Note: Descriptions are shown in the official language in which they were submitted.
CA 02268590 1999-04-12
1
ION CHANNEL MODULATING COMPOUNDS AND USES THEREOF
TECHNICAL FIELD
The present invention is generally directed toward ion channel
modulating compounds, pharmaceutical compositions and kits containing the ion
channel modulating compounds, and therapeutic uses thereof.
BACKGROUND OF THE INVENTION
Cardiac ion channels are proteins that reside in the cell membrane and
control the electrical activity of cardiac tissue. In response to external
stimuli, such as
changes in potential across the cell membrane, ion channels can form a pore
through the
cell membrane, and allow movement of specific ions into or out of the cell.
The
integrated behavior of thousands of ion channels in a single cell results in
an ion
current, and the integrated behavior of many ion currents makes up the
characteristic
cardiac action potential.
Arrhythmia is a variation from the normal rhythm of the heart beat and
generally represents the end product of abnormal ion-channel structure, number
or
function. Both atrial arrhythmias and ventricular arrhythmias are known. The
major
cause of fatalities due to cardiac arrhythmias is the subtype of ventricular
arrhythmias
known as ventricular fibrillation (VF). Conservative estimates indicate that,
in the U.S.
alone, each year over one million Americans will have a new or recurrent
coronary
attack (defined as myocardial infarction or fatal coronary heart disease).
About 650,000
of these will be first heart attacks and 450,000 will be recurrent attacks.
About one
third of the people experiencing these attacks will die of them. At least
250,000 people
a year die of coronary heart disease with 1 hour of the onset of symptoms and
before
they reach a hospital. These are sudden deaths caused by cardiac arrest,
usually
resulting from ventricular fibrillation.
Atrial fibrillation (AF) is the most common arrhythmia seen in clinical
practice and is a cause of morbidity in many individuals (Pritchett E.L., N.
Engl. J.
Med. 327(14):1031 Oct. 1, 1992, discussion 1031-2; Kannel and Wolf, Am. Heart
J.
CA 02268590 1999-04-12
2
123(1):264-7 Jan. 1992). Its prevalence is likely to increase as the
population ages and
it is estimated that 3-5% of patients over the age of 60 years have AF (Kannel
W.B.,
Abbot R.D., Savage D.D., McNamara P.M., N. Engl. J. Med. 306(17):1018-22,
1982;
Wolf P.A., Abbot R.D., Kannel W.B. Stroke. 22(8):983-8, 1991). While AF is
rarely
fatal, it can impair cardiac function and is a major cause of stroke (Hinton
R.C., Kistler
J.P., Fallon J.T., Friedlich A.L., Fisher C.M., American Journal of Cardiology
40(4):509-13, 1977; Wolf P.A., Abbot R.D., Kannel W.B., Archives of Internal
Medicine 147(9):1561-4, 1987; Wolf P.A., Abbot R.D., Kannel W.B. Stroke.
22(8):983-
8, 1991; Cabin H.S., Clubb K.S., Hall C., Perlmutter R.A., Feinstein A.R.,
American
Journal of Cardiology 65(1 x:1112-6, 1990).
Antiarrhythmic agents have been developed to prevent or alleviate
cardiac arrhythmia. For example, Class I antiarrhythmic compounds have been
used to
treat supraventricular arrhythmias and ventricular arrhythmias. Treatment of
ventricular
arrhythmia is very important since such an arrhythmia can be fatal. Serious
ventricular
arrhythmias (ventricular tachycardia and ventricular fibrillation) occur most
often in the
presence of myocardial ischemia and/or infarction. Ventricular fibrillation
often occurs
in the setting of acute myocardial ischemia, before infarction fully develops.
At
present, there is no satisfactory pharmacotherapy for the treatment and/or
prevention of
ventricular fibrillation during acute ischemia. In fact, many Class I
antiarrhythmic
compounds may actually increase mortality in patients who have had a
myocardial
infarction.
Class Ia, Ic and III antiarrhythmic drugs have been used to convert recent
onset AF to sinus rhythm and prevent recurrence of the arrhythmia (Fuch and
Podrid,
1992; Nattel S., Hadjis T., Talajic M., Drugs 48(3):345-71, 1994). However,
drug
therapy is often limited by adverse effects, including the possibility of
increased
mortality, and inadequate efficacy (Feld G.K., Circulation. 830:2248-50, 1990;
Coplen S.E., Antman E.M., Berlin J.A., Hewitt P., Chalmers T.C., Circulation
1991;
83(2):714 and Circulation 82(4):1106-16, 1990; Flaker G.C., Blackshear J.L.,
McBride
R., Kronmal R.A., Halperin J.L., Hart R.G., Journal of the American College of
Cardiology 20(3):527-32, 1992; CAST, N. Engl. J. Med. 321:406, 1989; Nattel
S.,
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3
Cardiovascular Research. 37(3):567-77, 1998). Conversion rates for Class I
antiarrhythmics range between 50-90% (Mattel S., Hadjis T., Talajic M., Drugs
48(3):345-71, 1994; Steinbeck G., Remp T., Hoffmann E., Journal of
Cardiovascular
Electrophysiology. 9(8 Suppl):5104-8, 1998). Class III antiarrhythmics appear
to be
more effective for terminating atrial flutter than for AF and are generally
regarded as
less effective than Class I drugs for terminating of AF (Mattel S., Hadjis T.,
Talajic M.,
Drugs. 48(3):345-71, 1994; Capucci A., Aschieri D., Villani G.Q., Drugs &
Aging
13(1):51-70, 1998). Examples of such drugs include ibutilide, dofetilide and
sotalol.
Conversion rates for these drugs range between 30-50% for recent onset AF
(Capucci
A., Aschieri D., Villani G.Q., Drugs & Aging 13(1 ):51-70, 1998), but they are
also
associated with a risk of inducing the ventricular tachyarrhythmias known as
torsades
de pointes. For ibutilide, the risk of ventricular proarrhythmia is estimated
at ~4.4%,
with ~1.7% of patients requiring cardioversion for refractory ventricular
arrhythmias
(Kowey P.R., VanderLugt J.T., Luderer J.R., American Journal of Cardiology
78(8A):46-52, 1996). Such events are particularly tragic in the case of AF as
this
arrhythmia is rarely a fatal in and of itself.
Therefore, there is a need in the art to identify new antiarrhythmic
treatments, for both ventricular arrhythmias as well as for atrial
arrhythmias. The
present invention fulfills this need, and further provides other related
advantages.
SUMMARY OF THE INVENTION
As disclosed within the present invention, a variety of cardiac
pathological conditions may be treated and/or prevented by the use of one or
more ion
channel modulating compounds that either singly or together with one or more
additional compounds are able to selectively inhibit certain combination of
cardiac ionic
currents. More specifically, the cardiac currents referred to above are the
sodium
currents and early repolarising currents.
Early repolarising currents correspond to those cardiac ionic currents
which activate rapidly after depolarization of membrane voltage and which
effect
repolarisation of the cell. Many of these currents are potassium currents and
may
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4
include, but are not limited to, the transient outward current ho, such as
Kv4.2 and
Kv4.3), and the ultrarapid delayed rectifier current (IK~r) such as Kvl.S,
Kvl.4 and
Kv2.1). The ultrarapid delayed rectifier current (IK"~) has also been
described as ISUS. A
second calcium dependent transient outward current (Ito2) has also been
described.
The cardiac pathological conditions that may be treated and/or prevented
by the present invention may include, but are not limited to, arrhythmias such
as the
various types of atrial and ventricular arrhythmias.
In one embodiment, the present invention provides ion channel
modulating compounds that can be used to selectively inhibit cardiac early
repolarising
currents and cardiac sodium currents.
In another embodiment, the present invention provides ion channel
modulating compounds that can be used to selectively inhibit cardiac early
repolarising
currents and cardiac sodium currents under conditions where an "arrhythmogenic
substrate" is present in the heart. An "arrhythmogenic substrate" is
characterized by a
reduction in cardiac action potential duration and/or changes in action
potential
morphology, premature action potentials, high heart rates and may also include
increased variability in the time between action potentials and an increase in
cardiac
milieu acidity due to ischaemia or inflammation. Changes such as these are
observed
during conditions of myocardial ischaemia or inflammation and those conditions
that
precede the onset of arrhythmias such as atrial fibrillation.
In another embodiment, the present invention provides aminocyclohexyl
ether compounds of formula (I), or a solvate or pharmaceutically acceptable
salt thereof:
CA 02268590 1999-04-12
R5
A\
R1
,'N\
\R2
R4
R3
(I)
wherein, independently at each occurrence,
X is selected from a direct bond, -C(Rfi,R,4)-Y- and -C(R,3)=CH-;
5 Y is selected from a direct bond, O, S and C,-C4alkylene;
R,3 is selected from hydrogen, C,-Cbalkyl, C3-Cgcycloalkyl, aryl and
benzyl;
R, and RZ are independently selected from hydrogen, C,-Cgalkyl,
C3-CBalkoxyalkyl, C,-CBhydroxyalkyl, and C,-C,Zaralkyl; or
R, and RZ, when taken together with the nitrogen atom to which they are
directly attached in formula (I), form a ring denoted by formula (II):
N
~'RJ
~.- R2
(II)
wherein the ring of formula (II) is formed from the nitrogen as shown as well
as three to
nine additional ring atoms independently selected from carbon, nitrogen,
oxygen, and
sulfur; where any two adjacent ring atoms may be joined together by single or
double
bonds, and where any one or more of the additional carbon ring atoms may be
substituted with one or two substituents selected from hydrogen, hydroxy,
C,-C3hydroxyalkyl, oxo, CZ-C4acyl, C1-C3alkyl, CZ-C4alkylcarboxy, C1-C3alkoxy,
C,-
Czoalkanoyloxy, or may be substituted to form a spiro five- or six-membered
heterocyclic ring containing one or two heteroatoms selected from oxygen and
sulfur;
CA 02268590 1999-04-12
6
and any two adjacent additional carbon ring atoms may be fused to a C3-
CBCarbocyclic
ring, and any one or more of the additional nitrogen ring atoms may be
substituted with
substituents selected from hydrogen, C,-Cbalkyl, Cz-C4acyl, CZ-C4hydroxyalkyl
and
C3-CBalkoxyalkyl; or
R, and RZ, when taken together with the nitrogen atom to which they are
directly attached in formula (I), may form a bicyclic ring system selected
from
3-azabicyclo[3.2.2]nonan-3-yl, 2-azabicyclo[2.2.2]octan-2-yl, 3-
azabicyclo[3.1.0]-
hexan-3-yl and 3-azabicyclo[3.2.0]heptan-3-yl;
R3 and R4 are independently attached to the cyclohexane ring shown in
formula (I) at the 3-, 4-, 5- or 6- positions and are independently selected
from
hydrogen, hydroxy, C,-Cbalkyl and C,-Cbalkoxy, and, when both R3 and R4 are
attached
to the same cyclohexane ring atom, may together form a spiro five- or six-
membered
heterocyclic ring containing one or two heteroatoms selected from oxygen and
sulfur;
R5, R6 and R,4 are independently selected from hydrogen, C,-Cbalkyl,
aryl and benzyl, or R6 and R,4, when taken together with the carbon to which
they are
attached, may form a spiro C3-Cscycloalkyl;
A is selected from CS-C,Zalkyl, a C3-C,3carbocyclic ring, and ring
systems selected from formulae (III), (IV), (V), (VI), (VII) and (VIII):
R~
R
(III)
where R,, R8 and R, are independently selected from bromine, chlorine,
fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido,
nitro,
sulfamyl, trifluoromethyl, CZ-C,alkanoyloxy, C,-Cbalkyl, C,-Cbalkoxy,
CZ-C,alkoxycarbonyl, C,-Cbthioalkyl, aryl and N(R,S,R,6) where R,5 and R,6 are
independently selected from hydrogen, acetyl, methanesulfonyl and C,-Cbalkyl;
CA 02268590 1999-04-12
/ \ / \
Rto Rt t Rto Rt t
\ / \ /
and
(IV) (V)
where R,o and R" are independently selected from bromine, chlorine,
fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido,
nitro,
sulfamyl, trifluoromethyl, CZ-C,alkanoyloxy, C,-Cbalkyl, C,-C6alkoxy,
CZ-C,alkoxycarbonyl, C,-Cbthioalkyl, and N(R,S,R,6) where R,5 and R,6 are
independently selected from hydrogen, acetyl, methanesulfonyl, and C,-Cbalkyl;
Rt2 \ Z~
(VI)
where R,2 is selected from bromine, chlorine, fluorine, carboxy,
hydrogen, hydroxy, hydroxymethyl, methanesulfonamido, nitro, sulfamyl,
trifluoromethyl, CZ-C~alkanoyloxy, C,-C6alkyl, C,-Cbalkoxy, Cz-
C,alkoxycarbonyl,
C,-Cbthioalkyl, and N(R,S,R,6) where R,5 and R,6 are independently selected
from
hydrogen, acetyl, methanesulfonyl, and C,-Cbalkyl; and Z is selected from CH,
CHz, O,
N and S, where Z may be directly bonded to "X" as shown in formula (I) when Z
is CH
or N, or Z may be directly bonded to R" when Z is N, and R,~ is selected from
hydrogen, C,-Cbalkyl, C3-CBCycloalkyl, aryl and benzyl;
/ \ ~-
\ ~ /
(VII) (VIII)
including isolated enantiomeric, diastereomeric and geometric isomers
thereof, and mixtures thereof.
CA 02268590 1999-04-12
g
In other embodiments, the present invention provides a composition or
medicament that includes a compound according to formula (I) in combination
with a
pharmaceutically acceptable carrier, diluent or excipient, and further
provides a method
for the manufacture of a composition or medicament that contains a compound
according to formula (I).
In other embodiments, the present invention provides pharmaceutical
compositions that contain at least one compound of formula (I) in an amount
effective
to treat a disease or condition in a warm-blooded animal suffering from or
having the
disease or condition, and/or prevent a disease or condition in a warm-blooded
animal
that would otherwise occur, and further contains at least one pharmaceutically
acceptable carrier, diluent or excipient. The invention further provides for
methods of
treating a disease or condition in a warm-blooded animal suffering from or
having the
disease or condition, and/or preventing a disease or condition from arising in
a warm-
blooded animal, wherein a therapeutically effective amount of a compound of
formula
(I), or a composition containing a compound of formula (I) is administered to
a warm-
blooded animal in need thereof. The diseases and conditions to which the
compounds,
compositions and methods of the present invention have applicability are as
follows:
arrhythmia, diseases of the central nervous system, convulsion, epileptic
spasms,
depression, anxiety, schizophrenia, Parkinson's disease, respiratory
disorders, cystic
fibrosis, asthma, cough, inflammation, arthritis, allergies, gastrointestinal
disorders,
urinary incontinence, irritable bowel syndrome, cardiovascular diseases,
cerebral or
myocardial ischemias, hypertension, long-QT syndrome, stroke, migraine,
ophthalmic
diseases, diabetes mellitus, myopathies, Becker's myotonia, myasthenia gravis,
paramyotonia congentia, malignant hyperthermia, hyperkalemic periodic
paralysis,
Thomsen's myotonia, autoimmune disorders, graft rejection in organ
transplantation or
bone marrow transplantation, heart failure, hypotension, Alzheimer's disease
or other
metal disorder, and alopecia.
In another embodiment, the present invention provides a pharmaceutical
composition containing an amount of a compound of formula (I) effective to
produce
local analgesia or anesthesia in a warm-blooded animal in need thereof, and a
CA 02268590 1999-04-12
9
pharmaceutically acceptable carrier, diluent, or excipient. The invention
further
provides a method for producing, local analgesia or anesthesia in a warm-
blooded
animal which includes administering to a warm-blooded animal in need thereof
an
effective amount of a compound of formula (I) or a pharmaceutical composition
containing a compound of formula (I). These compositions and methods may be
used
to relieve or forestall the sensation of pain in a warm-blooded animal.
In another embodiment, the present invention provides a pharmaceutical
composition containing an amount of a compound of formula (I) effective to
enhance
the libido in a warm-blooded animal in need thereof, and a pharmaceutically
acceptable
carrier, diluent, or excipient. The invention further provides a method for
enhancing
libido in a warm-blooded animal which includes administering to a warm-blooded
animal in need thereof an effective amount of a compound of formula (I) or a
pharmaceutical composition containing a compound of formula (I). These
compositions and methods may be used, for example, to treat a sexual
dysfunction, e.g.,
impotence in males, and/or to enhance the sexual desire of a patient without a
sexual
dysfunction. As another example, the therapeutically effective amount may be
administered to a bull (or other breeding stock), to promote increased semen
ejaculation, where the ejaculated semen is collected and stored for use as it
is needed to
impregnate female cows in promotion of a breeding program.
In another embodiment, the present invention provides a compound of
formula (I) or composition containing a compound of formula (I), for use in
methods
for either modulating ion channel activity in a warm-blooded animal or for
modulating
ion channel activity in vitro.
These and other embodiments of the present invention will become
evident upon reference to the following drawings and detailed description.
CA 02268590 1999-04-12
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates the reaction sequence further described in Example 1,
for preparing an aminocyclohexyl ether compound of the present invention.
Figure 2 illustrates a procedure whereby either cis- or trans-
5 aminocyclohexyl ether compounds of the present invention may be prepared.
Figure 3 illustrates synthetic methodology that may be employed to
prepare either cis or traps stereoisomers of the compounds of the present
invention.
Figures 4A and 4B illustrate the synthetic methodology described in
Example 15.
10 DETAILED DESCRIPTION OF THE INVENTION
As briefly noted above, in one aspect the present invention provides for
the treatment and/or prevention of a variety of cardiac pathological
conditions by the
use of one or more ion channel modulating compounds that either singly, or
together
with one or more additional compounds, are able to inhibit selective cardiac
ionic
currents. More specifically, the cardiac currents referred to above are the
sodium
currents and early repolarising currents.
Early repolarising currents correspond to those cardiac ionic currents
which activate rapidly after depolarisation of membrane voltage and which
effect
repolarisation of the cell. Many of these currents are potassium currents and
may
include, but are not limited to, the transient outward current (I,ol such as
Kv4.2 and
Kv4.3), and the ultrarapid delayed rectifier current (IKu~ such as Kvl.S,
Kvl.4, and
Kv2.1 ). The ultrarapid delayed rectifier current (IKur) has also be described
as IS"S. A
second calcium dependent transient outward current (hoz) has also been
described.
The cardiac pathological conditions that may be treated and/or prevented
by the novel methods of the present invention may include, but are not limited
to,
arrhythmias such as the various types of atrial (supraventricular) and
ventricular
arrhythmias. The compounds of the present invention are especially useful in
treating
and/or preventing atrial fibrillation and ventricular fibrillation.
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11
The novel methods of the present invention are especially useful under
conditions where an "arrhythmogenic substrate" is present in the heart. An
"arrhythmogenic substrate" is characterized by a reduction in cardiac action
potential
duration and/or changes in action potential morphology, premature action
potentials,
high heart rates and may also include increased variability in the time
between action
potentials and an increase in cardiac milieu acidity due to ischaemia or
inflammation.
Changes such as these are observed during conditions of myocardial ischaemia
or
inflammation (Janse & Wit, Physiol. Rev. 69(4):1049-169, Oct. 1989), and those
conditions that precede the onset of arrhythmias such as atrial fibrillation
(Pichlmaier et
al. Heart 80(5):467-72, Nov. 1998). Under conditions described above for
cardiac
arrhythmias in general, there is an increase in acidity of the cardiac milieu
from the
normal physiological pH (i. e., the pH of the milieu is lower than normal).
In the novel methods of the present invention of treating and/or
preventing arrhythmia, one or more ion channel modulating compounds, either
singly or
1 S together, are used to inhibit selective cardiac sodium currents and
cardiac early
repolarising currents. It is preferable that the ion channel modulating
compounds
generally have a pKa value of about 4 to 9 and more preferably less than about
8. The
most preferred pKa values are between about 5 and 7.5. Methods to determine
pKa
values are well known in the art (see, e.g., Perrin, "Dissociation Constants
of Organic
Bases in Aqueous Solution", Butterworth, London, 1972). For compounds of the
present invention with a preferred pKa value, the fraction of the charged
(protonated)
species will be increased under the pathological conditions such as cardiac
arrhythmias
and the presence of an arrhythmogenic substrate in the heart as described
above due to
the increase in cardiac milieu acidity. Where the charged form of a compound
is active,
its potency increases under conditions associated with an increases in cardiac
milieu
acidity.
In other methods of the present invention of treating and/or preventing
arrhythmia, one or more ion channel modulating compounds, either singly or
together
with one or more additional compounds, are used to inhibit selective cardiac
ionic
currents. More specifically, the cardiac currents referred to above are the
sodium
CA 02268590 1999-04-12
12
currents and early repolarising currents. It is preferable that the ion
channel modulating
compounds block the said cardiac currents from extracellular loci. Such
compounds act
on an external locus of the ion channel that is accessible from the
extracellular surface.
This facilitates access to the ion channel and provides rapid onset kinetics
and exhibits
frequency dependent blockade of currents. Such properties are all beneficial
for
compounds used to treat arrhythmias.
The novel methods of the present invention provide treatment and/or
prevention of arrhythmias that do not prolong action potential duration in
normal
cardiac ventricle but rather prolongs action potential duration under
conditions when an
arrhythmogenic substrate is present in the heart. Blockade of early, rather
than late
repolarising currents will prolong action potential duration under conditions
where
action potential duration has been previously reduced. Blockade of early,
rather than
late, repolarising currents offers another advantage over existing methods.
Blockade of
late repolarising currents such as IK, (HERG) and IKS (minx-LQT) prolongs
action
potential under normal conditions. In so doing there is a risk of
precipitating a
polymorphic ventricular tachycardia commonly called torsade de pointes which
can be
fatal (Mattel, 1998). As blockade of early repolarising currents does not
prolong action
potential duration under normal conditions, the novel methods of the present
invention
greatly reduce such proarrhythmia risk.
Methods for in vitro assessment of inhibition activity of ion channel
modulating compounds on different cardiac ion currents are well known in the
art and
are briefly described in Example 33 below.
Methods for assessment of proarrhythmia (e.g., torsade de pointes) risk
of ion channel modulating compounds are also published in the literature and
are briefly
described in Example 34 below.
In the novel methods of the present invention of treating and/or
preventing arrhythmia, one or more ion channel modulating compounds, either
singly or
together, are used to inhibit selective cardiac sodium currents and cardiac
early
repolarising currents. The concentration of each compound is typically between
0.001
and 30 ~M.
CA 02268590 1999-04-12
13
Thus, the present invention is directed to ion channel modulating
compounds that block cardiac early repolarising currents and cardiac sodium
currents.
The ion channel modulating compounds block the cardiac ion channels
responsible for
early repolarising currents and sodium currents; and/or block cardiac early
repolarising
currents and cardiac sodium currents under conditions where an arrhythmogenic
substrate is present in the heart; and/or block the cardiac ion channels
responsible for
early repolarising currents and sodium currents under conditions where an
arrhythmogenic substrate is present in the heart; and/or block cardiac early
repolarising
currents and cardiac sodium currents from extracellular loci in cardiac cells;
and/or have
pKa values of between 4-9, preferably having have pKa values of between 5-7.5.
In one embodiment, the cardiac early repolarising currents referred to
above comprise ionic currents which activate rapidly after depolarisation of
membrane
voltage and which effect repolarisation of the cell. The early repolarising
currents may
comprise the cardiac transient outward potassium current (Ito) and/or the
ultrarapid delay
rectifier current (IKurO The cardiac transient outward potassium current (ho)
and/or the
ultrarapid delay rectifier current (IK~r) may comprise at least one of the
Kv4.2, Kv4.3,
Kv2.1, Kv 1.4 and Kv 1.5 currents.
The invention also provides a composition comprising one or more of
the above-described ion channel modulating compounds in combination with a
pharmaceutically acceptable carrier, excipient or diluent.
The present invention provides that the above-described ion channel
modulating compounds) and/or compositions) containing same may be used in a
method for treating or preventing arrhythmia in a warm-blooded animal; and/or
may be
used in a method for modulating ion channel activity in a warm-blooded animal;
and/or
may be used in a method for modulating ion channel activity in vitro.
The invention also provides for the use of an ion channel modulating
compound in a manufacture of a medicament.
The invention further provides a pharmaceutical composition comprising
(a) an amount of an ion modulating compound as described above effective to
treat or
prevent atrial arrhythmia in a warm-blooded animal in need of the treatment or
CA 02268590 1999-04-12
14
prevention, and (b) a pharmaceutically acceptable carrier, diluent, or
excipient.
According to the present invention, this composition may be used in a method
for
treating or preventing atrial arrhythmia in a warm-blooded animal, where the
method
comprises administering to a warm-blooded animal in need thereof a
therapeutically
effective amount of one of the above-described ion channel modulating
compounds or a
composition containing same.
The invention further provides a pharmaceutical composition comprising
(a) an amount of an ion channel modulating compound as described above
effective to
treat or prevent ventricular arrhythmia in a warm-blooded animal in need of
the
treatment or prevention, and (b) a pharmaceutically acceptable carrier,
diluent, or
excipient. This composition may be used in a method for treating or preventing
ventricular arrhythmia in a warm-blooded animal, where the method comprises
administering to a warm-blooded animal in need thereof a therapeutically
effective
amount of one of the above-described ion channel modulating compounds or a
composition containing same.
The invention further provides a method for inhibiting multiple cardiac
ionic current, where the method comprises administering to a warm-blooded
animal in
need thereof one or more compounds that either singly or together both block
cardiac
early repolarising currents and cardiac sodium currents, said one or more
compounds
being administered in an amount effective to block cardiac sodium currents and
cardiac
early repolarising currents. In this method, said one or more compounds may
either
singly or together both block cardiac early repolarising currents and cardiac
sodium
currents from extracellular loci in cardiac cells.
The present invention also provides a method for inhibiting multiple
cardiac ionic currents, where the method comprises administering to a warm-
blooded
animal in need thereof one or more compounds that either singly or together
both block
the cardiac ion channels responsible for early repolarising currents and
sodium
channels, said one or more compounds being administered in an amount effective
to
block the cardiac sodium ion channels and the cardiac early repolarising ion
channels.
In this method, said one or more compounds may either singly or together both
block
CA 02268590 1999-04-12
1S
cardiac ion channels responsible for early repolarising currents and sodium
currents
from extracellular loci in cardiac cells. Also in this method one compound may
block
both sodium currents and cardiac early repolarising currents from
extracellular loci in
cardiac cells. Also in these methods, each of said one or more compounds may
have a
pKa value of less than 8.
The invention in addition provides a method for treating or preventing a
cardiac condition wherein there is an "arrhythmogenic substrate" present in
the heart,
where the method comprises administering to a warm-blooded animal in need
thereof,
in an amount effective to treat or prevent said cardiac condition, one or more
compounds that either singly or together block cardiac early repolarising
currents and
cardiac sodium currents. In this method, said one or more compounds may either
singly
or together both block cardiac early repolarising currents and cardiac sodium
currents
from extracellular loci in cardiac cells. Also in this method, one compound
may both
block cardiac early repolarising currents and cardiac sodium currents from
extracellular
loci in cardiac cells. Also in these methods, each of said one or more
compounds may
have a pKa value of less than 8.
Furthermore, the present invention provides a method for treating or
preventing a cardiac condition wherein there is an "arrhythmogenic substrate"
present in
the heart, where this method comprises administering to a warm-blooded animal
in need
thereof, in an amount effective to treat or prevent said cardiac condition,
one or more
compounds that either singly or together both block cardiac ion channels
responsible for
early repolarising currents and sodium currents. In this method, said one or
more
compounds may either singly or together both block cardiac ion channels
responsible
for early repolarising currents and sodium currents from extracellular loci in
cardiac
cells. Also in this method, one compound may both block cardiac ion channels
responsible for early repolarising currents and sodium currents from
extracellular loci in
cardiac cells. Additionally in this method, each of said one or more compounds
may
have a pKa value of less than 8.
The present invention provides a method for treating or preventing a
cardiac condition wherein there is an increase in acidity from the normal
physiological
CA 02268590 1999-04-12
16
pH of the cardiac milieu, where the method comprises administering to a warm-
blooded
animal in need thereof, in an amount effective to treat or prevent said
cardiac condition,
one or more compounds that either singly or together both block cardiac early
repolarising currents and cardiac sodium currents. In this method, said one or
more
compounds may either singly or together both block cardiac ion channels
responsible
for early repolarising currents and sodium currents from extracellular loci in
cardiac
cells. Also in this method, one compound may block cardiac ion channels
responsible
for early repolarising currents and in addition block sodium currents from
extracellular
loci in cardiac cells. In this method, each of said one or more compounds may
have a
pKa value of less than 8.
The present invention also provides a method for treating or preventing a
cardiac condition wherein there is an increase in acidity from the normal
physiological
pH of the cardiac milieu, where the method comprises administering to a warm-
blooded
animal in need thereof, in an amount effective to treat or prevent said
cardiac condition,
one or more compounds that either singly or together both block cardiac ion
channels
responsible for early repolarising currents and sodium currents. In this
method, said
one or more compounds may either singly or together both block cardiac ion
channels
responsible for early repolarising currents and sodium currents from
extracellular loci in
cardiac cells. Also in this method, one compound may both block cardiac ion
channels
responsible for early repolarising currents and sodium currents from
extracellular loci in
cardiac cells. Additionally, in this method, each of said one or more
compounds may
have a pKa value of less than 8.
In a preferred embodiment, in the above-described methods, the cardiac
condition is ventricular arrhythmia. In another preferred embodiment, in the
above-
described methods, the cardiac condition is atrial arrhythmia. In some
instances, the
increase in acidity of the cardiac milieu is due to myocardial ischaemia.
Additionally,
or alternatively, the increase in acidity of the cardiac milieu is due to high
heart rate.
Additionally, or alternatively, the increase in acidity is due to
inflammation.
Additionally, or alternatively, the increase in acidity is due to the presence
of an
CA 02268590 1999-04-12
1~
"arrhythmogenic substrate" in the heart. Additionally, or alternatively, the
increase in
acidity is due to conditions which precede atrial fibrillation.
In another aspect, the present invention is directed to aminocyclohexyl
ether compounds, pharmaceutical compositions containing the aminocyclohexyl
ether
compounds, and various uses for the compound and compositions. Such uses
include
blockage of ion channels in vitro or in vivo, the treatment of arrhythmias,
the production
of anesthesia, and other uses as described herein. An understanding of the
present
invention may be aided by reference to the following definitions and
explanation of
conventions used herein.
Definitions and Conventions
The aminocyclohexyl ether compounds of the invention have an ether
oxygen atom at position 1 of a cyclohexane ring, and an amine nitrogen atom at
position 2 of the cyclohexane ring, with other positions numbered in
corresponding
order as shown below in structure (A):
O
N\
'6
5
(A)
The bonds from the cyclohexane ring to the 1-oxygen and 2-nitrogen
atoms in the above formula may be relatively disposed in either a cis or traps
relationship. In a preferred embodiment of the present invention, the
stereochemistry of
the amine and ether substituents of the cyclohexane ring is either (R,R)-traps
or
(S,S)-traps. In another preferred embodiment the stereochemistry is either
(R,S)-cis or
(S,R)-cis.
In the formulae depicted herein, a bond to a substituent and/or a bond
that links a molecular fragment to the remainder of a compound may be shown as
CA 02268590 1999-04-12
1g
intersecting one or more bonds in a ring structure. This indicates that the
bond may be
attached to any one of the atoms that constitutes the ring structure, so long
as a
hydrogen atom could otherwise be present at that atom. Where no particular
substituent(s) is identified for a particular position in a structure, then
hydrogen(s) is
present at that position. For example, compounds of the invention containing
the
A-X-CH(RS)- group where A equals formula (III)
R~ \
R9
s
(III)
are intended to encompass compounds having the group (B):
R~ \ X-CH(Rs)-
Rg
(B)
where the group (B) is intended to encompass groups wherein any ring atom that
could
otherwise be substituted with hydrogen, may instead be substituted with either
R,, Rg or
R9, with the proviso that each of R,, R8 and R9 appears once and only once on
the ring.
Ring atoms that are not substituted with any of R,, Rg or R, are substituted
with
hydrogen. In those instances where the invention specifies that a non-aromatic
ring is
substituted with more than one R group, and those R groups are shown connected
to the
non-aromatic ring with bonds that bisect ring bonds, then the R groups may be
present
at different atoms of the ring, or on the same atom of the ring, so long as
that atom
could otherwise be substituted with a hydrogen atom.
Likewise, where the invention specifies compounds containing the
A-X-CH(RS)- group where A equals the aryl group (VI)
CA 02268590 1999-04-12
19
g a
f/
Rt2 a ~ ZJ-bs
d c
(VI)
the invention is intended to encompass compounds wherein -X-CH(RS)- is joined
through X to the aryl group (VI) at any atom which forms the aryl group (VI)
so long as
that atom of group (VI) could otherwise be substituted with a hydrogen atom.
Thus,
there are seven positions (identified with the letters "a" through "g") in
structure (VI)
where the -X-CH(RS)- group could be attached, and it is attached at one of
those seven
positions. The R,Z group would occupy one and only one of the remaining six
positions, and hydrogen atoms would be present in each of the five remaining
positions.
It is to be understood that when Z represents a divalent atom, e.g., oxygen or
sulfur,
then Z cannot be directly bonded to -X-CH(RS)-.
When the invention specifies the location of an asymmetric divalent
radical, then that divalent radical may be positioned in any possible manner
that
provides a stable chemical structure. For example, for compounds containing
the
A-X-CH(RS)- group where X is C(R,4,R6)-Y-, the invention provides compounds
having
both the A-C(R,4,R6)-Y-CH(RS)- and A-Y-C(R,4,R~)-CH(RS)- groups.
A wavy bond from a substituent to the central cyclohexane ring indicates
that that group may be located on either side of the plane of the central
ring.
The compounds of the present invention contain at least two asymmetric
carbon atoms and thus exist as enantiomers and diastereomers. Unless otherwise
noted,
the present invention includes all enantiomeric and diastereomeric forms of
the
aminocyclohexyl ether compounds of the invention. Pure stereoisomers, mixtures
of
enantiomers and/or diastereomers, and mixtures of different compounds of the
invention are included within the present invention. Thus, compounds of the
present
invention may occur as racemates, racemic mixtures and as individual
diastereomers, or
enantiomers with all isomeric forms being included in the present invention. A
racemate or racemic mixture does not imply a 50:50 mixture of stereoisomers.
CA 02268590 1999-04-12
The phrase "independently at each occurrence" is intended to mean (i)
when any variable occurs more than one time in a compound of the invention,
the
definition of that variable at each occurrence is independent of its
definition at every
other occurrence; and (ii) the identity of any one of two different variables
(e.g., R,
5 within the set R~ and RZ) is selected without regard the identity of the
other member of
the set. However, combinations of substituents and/or variables are
permissible only if
such combinations result in stable compounds.
In accordance with the present invention and as used herein, the
following terms are defined to have following meanings, unless explicitly
stated
10 otherwise:
"Acid addition salts" refers to those salts which retain the biological
effectiveness and properties of the free bases and which are not biologically
or
otherwise undesirable, formed with inorganic acids such as hydrochloric acid,
hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, or
organic
15 acids such as acetic acid, propionic acid, glycolic acid, pyruvic acid,
oxalic acid, malefic
acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid,
benzoic acid,
cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-
toluenesulfonic acid, salicylic acid and the like.
"Acyl" refers to branched or unbranched hydrocarbon fragments
20 terminated by a carbonyl -(C=O)- group containing the specified number of
carbon
atoms. Examples include acetyl [CH3C=O-, a Czacyl] and propionyl [CH3CHZC=O-,
a
C3acy1].
"Alkanoyloxy" refers to an ester substituent wherein the ether oxygen is
the point of attachment to the molecule. Examples include propanoyloxy
[(CH3CHZC=O-O-, a C3alkanoyloxy] and ethanoyloxy [CH3C=O-O-, a CZalkanoyloxy].
"Alkoxy" refers to an O-atom substituted by an alkyl group, for example,
methoxy [-OCH3, a C,alkoxy].
"Alkoxyalkyl" refers to a alkylene group substituted with an alkoxy
group. For example, methoxyethyl [CH30CHZCH2-] and ethoxymethyl
(CH3CHzOCHz-] are both C3alkoxyalkyl groups.
CA 02268590 1999-04-12
21
"Alkoxycarbonyl" refers to an ester substituent wherein the carbonyl
carbon is the point of attachment to the molecule. Examples include
ethoxycarbonyl
[CH3CHzOC=O-, a C3alkoxycarbonyl] and methoxycarbonyl [CH30C=O-, a
CZalkoxycarbonyl].
"Alkyl" refers to a branched or unbranched hydrocarbon fragment
containing the specified number of carbon atoms and having one point of
attachment.
Examples include n-propyl (a C3alkyl), iso-propyl (also a C3alkyl), and t-
butyl (a
C4alkyl).
"Alkylene" refers to a divalent radical which is a branched or unbranched
hydrocarbon fragment containing the specified number of carbon atoms, and
having two
points of attachment. An example is propylene [-CHzCHzCH2-, a C3alkylene].
"Alkylcarboxy" refers to a branched or unbranched hydrocarbon
fragment terminated by a carboxylic acid group [-COOH]. Examples include
carboxymethyl [HOOC-CHZ-, a Czalkylcarboxy] and carboxyethyl [HOOC-CHzCH2-, a
C3alkylcarboxy].
"Aryl" refers to aromatic groups which have at least one ring having a
conjugated pi electron system and includes carbocyclic aryl, heterocyclic aryl
(also
known as heteroaryl groups) and biaryl groups, all of which may be optionally
substituted. Carbocyclic aryl groups are generally preferred in the compounds
of the
present invention, where phenyl and naphthyl groups are preferred carbocyclic
aryl
groups.
"Aralkyl" refers to an alkylene group wherein one of the points of
attachment is to an aryl group. An example of an aralkyl group is the benzyl
group
[C6HSCHz-, a C,aralkyl group].
"Cycloalkyl" refers to a ring, which may be saturated or unsaturated and
monocyclic, bicyclic, or tricyclic formed entirely from carbon atoms. An
example of a
cycloalkyl group is the cyclopentenyl group (CSH,-), which is a five carbon
(CS)
unsaturated cycloalkyl group.
"Carbocyclic" refers to a ring which may be either an aryl ring or a
cycloalkyl ring, both as defined above.
CA 02268590 1999-04-12
22
"Carbocyclic aryl" refers to aromatic groups wherein the atoms which
form the aromatic ring are carbon atoms. Carbocyclic aryl groups include
monocyclic
carbocyclic aryl groups such as phenyl, and bicyclic carbocyclic aryl groups
such as
naphthyl, all of which may be optionally substituted.
"Heteroatom" refers to a non-carbon atom, where boron, nitrogen,
oxygen, sulfur and phosphorus are preferred heteroatoms, with nitrogen, oxygen
and
sulfur being particularly preferred heteroatoms in the compounds of the
present
mventlon.
"Heteroaryl" refers to aryl groups having from 1 to 9 carbon atoms and
the remainder of the atoms are heteroatoms, and includes those heterocyclic
systems
described in "Handbook of Chemistry and Physics," 49th edition, 1968, R.C.
Weast,
editor; The Chemical Rubber Co., Cleveland, OH. See particularly Section C,
Rules for
Naming Organic Compounds, B. Fundamental Heterocyclic Systems. Suitable
heteroaryls include furanyl, thienyl, pyridyl, pyrrolyl, pyrimidyl, pyrazinyl,
imidazolyl,
and the like.
"Hydroxyalkyl" refers to a branched or unbranched hydrocarbon
fragment bearing an hydroxy (-OH) group. Examples include hydroxymethyl
(-CHZOH, a C,hydroxyalkyl) and 1-hydroxyethyl (-CHOHCH3, a CZhydroxyalkyl).
"Thioalkyl" refers to a sulfur atom substituted by an alkyl group, for
example thiomethyl (CH3S-, a C,thioalkyl).
"Modulating" in connection with the activity of an ion channel means
that the activity of the ion channel may be either increased or decreased in
response to
administration of a compound or composition or method of the present
invention. Thus,
the ion channel may be activated, so as to transport more ions, or may be
blocked, so
that fewer or no ions are transported by the channel.
"Pharmaceutically acceptable carriers" for therapeutic use are well
known in the pharmaceutical art, and are described, for example, in Remingtons
Pharmaceutical Sciences, Mack Publishing Co. (A.R. Gennaro edit. 1985). For
example, sterile saline and phosphate-buffered saline at physiological pH may
be used.
Preservatives, stabilizers, dyes and even flavoring agents may be provided in
the
CA 02268590 1999-04-12
23
pharmaceutical composition. For example, sodium benzoate, sorbic acid and
esters of
p-hydroxybenzoic acid may be added as preservatives. Id. at 1449. In addition,
antioxidants and suspending agents may be used. Id.
"Pharmaceutically acceptable salt" refers to salts of the compounds of
the present invention derived from the combination of such compounds and an
organic
or inorganic acid (acid addition salts) or an organic or inorganic base (base
addition
salts). The compounds of the present invention may be used in either the free
base or
salt forms, with both forms being considered as being within the scope of the
present
invention.
The "therapeutically effective amount" of a compound of the present
invention will depend on the route of administration, the type of warm-blooded
animal
being treated, and the physical characteristics of the specific warm-blooded
animal
under consideration. These factors and their relationship to determining this
amount are
well known to skilled practitioners in the medical arts. This amount and the
method of
administration can be tailored to achieve optimal efficacy but will depend on
such
factors as weight, diet, concurrent medication and other factors which those
skilled in
the medical arts will recognize.
Compositions described herein as "containing a compound of formula
(I)" encompass compositions that contain more than one compound of formula
(I).
CA 02268590 1999-04-12
24
Compounds of the Present Invention
The compounds of the present invention are amines which may be
represented by formula (I):
R5
A~
~1
//N\
'R2
R4
R3
(I)
Compounds of formula (I) are aminocyclohexyl ethers. More specifically, these
aminocyclohexyl ethers are substituted at position 2 of the cyclohexyl ring
with an
amine group -NR,Rz. The cyclohexyl ring may also be substituted with
additional
substituents (designated as R3 and R4) as described in more detail below.
Examples of
specific embodiments of compounds represented by formula (I) are described
below
Depending upon the selection of substituents R, and RZ, the compounds
of formula (I) may be primary, secondary, or tertiary amines (i.e., both R,
and RZ are
hydrogen, only one of R, and RZ is hydrogen, or neither of R, and RZ are
hydrogen,
respectively). Where the amine is tertiary, it may be a cyclic amine. Amine
substituents R~ and RZ may be independently selected from substituents which
include
hydrogen, alkyl groups containing from one to eight carbon atoms (i.e., C,-
Cgalkyl),
alkoxyalkyl groups containing from three to eight carbon atoms (i.e., C3-
CBalkoxyalkyl),
alkyl groups containing from one to eight carbon atoms where one of the carbon
atoms
is substituted with a hydroxyl group (i.e., C,-Cghydroxyalkyl), and aralkyl
groups
containing from seven to twelve carbon atoms (i.e., C,-C,Zaralkyl).
Alternatively, R, and R2, when taken together with the nitrogen atom to
which they are directly attached in formula (I), may form a ring denoted by
formula (II):
CA 02268590 1999-04-12
~N R
R2
(II)
wherein the ring of formula (II) is formed from the nitrogen as shown as well
as three to
nine additional ring atoms independently selected from carbon, nitrogen,
oxygen, and
5 sulfur; where any two adjacent ring atoms may be joined together by single
or double
bonds, and where any one or more of the additional carbon ring atoms may be
substituted with one or two substituents selected from hydrogen, hydroxy,
C,-C3hydroxyalkyl, oxo, CZ-C4acyl, CI-C3alkyl, CZ-C4alkylcarboxy, C~-C3alkoxy,
C,-
Czoalkanoyloxy, or may be substituted to form a spiro five- or six-membered
10 heterocyclic ring containing one or two heteroatoms selected from oxygen
and sulfur
(e.g., an acetal, thioacetal, ketal, or thioketal group); and any two adjacent
additional
carbon ring atoms may be fused to a C3-Cgcarbocyclic ring, and any one or more
of the
additional nitrogen ring atoms may be substituted with substituents selected
from
hydrogen, C,-C6alkyl, CZ-C4acyl, CZ-C4hydroxyalkyl and C3-CBalkoxyalkyl.
Examples
15 of substituents containing a fused ring system include the perhydroindolyl
and
1,2,3,4-tetrahydroisoquinolinyl groups.
In connection with the ring of formula (II), any two adjacent ring atoms
may be joined together by single or double bonds. Thus, the ring of formula
(II) may be
saturated or unsaturated, and an unsaturated ring may contain one, or more
than one,
20 sites of unsaturation. In other words, the ring of formula (II) may contain
one or more
double bonds, it being understood, however, that the unsaturated ring of
formula (II) is
chemically stable.
Alternatively, R, and RZ, when taken together with the 2-amino nitrogen
of formula (I), may complete a bicyclic ring. Bicyclic rings include, for
example,
25 3-azabicyclo[3.2.2]nonane, 2-azabicyclo[2.2.2]octane, 3-
azabicyclo[3.1.0]hexane, and
3-azabicyclo[3.2.0]heptane. For these derivatives, the 2-substituents of the
cyclohexyl
ethers of formula (I) are the following groups: 3-azabicyclo[3.2.2]nonan-3-yl,
2-azabicyclo[2.2.2]octan-2-yl, 3-azabicyclo[3.1.0]hexan-3-yl, and 3-
azabicyclo[3.2.0]-
heptan-3-yl.
CA 02268590 1999-04-12
26
Preferably, R, and R2, when taken together, contain only a single
heteroatom. Preferred heteroatoms include nitrogen, oxygen and sulfur. An
example of
a ring in which R, and RZ together include an oxygen heteroatom is the
morpholinyl
group. An example of a ring where R, and RZ together include a second nitrogen
heteroatom is the piperazinyl group.
Cyclohexane substituents R3 and R4 may be independently attached to
ring positions 3, 4, 5 or 6 (i.e., both R3 and R4 may be attached to the same
ring position
or each attached to different ring positions). R3 and R4 are independently
selected from
hydrogen, hydroxy, C,-Cbalkyl, and C,-Cbalkoxy, and, when both R3 and R4 are
attached
to the same cyclohexane ring atom, may together form a spiro five- or six-
membered
heterocyclic ring containing one or two heteroatoms selected from oxygen and
sulfur.
Preferred heterocyclic substituents contain either a single oxygen or a single
sulfur ring
atom.
Depending upon the identity of X, the ether side chain, -CH(RS)-X-A, in
formula (I) may take several forms. For example, a compound of formula (I) may
have
X as a -C(Rs,R,4)-Y- group, where Y may be any of a direct bond, an oxygen
atom (O),
a sulfur atom (S) or a C,-C4alkylene group. R6 and R,4 are independently
selected from
hydrogen, C,-Cbalkyl, aryl and benzyl, or R6 and R,4, when taken together with
the
carbon to which they are attached, may form a spiro C3-CSCycloalkyl. Thus,
compounds
of the invention include compounds of formula (I) where R6 and R,4 are
hydrogen and Y
is a direct bond, such that X may be CH2.
Alternatively, X may be an alkenylene moiety, e.g., a cis-or
traps-alkenylene moiety, C(R,3)=CH, where R,3 may be any of hydrogen, C,-
C6alkyl,
C3-CBcycloalkyl, aryl or benzyl. For compounds of formula (I) where X is an
alkenylene moiety, X is preferably a traps-alkenylene moiety.
Alternatively, X may be a direct bond. Independent of the selections for
A, X and other variables, RS is selected from hydrogen, C,-Cbalkyl, aryl and
benzyl.
Ether side chain component A is generally a hydrophobic moiety.
Typically, a hydrophobic moiety is comprised of non-polar chemical groups such
as
hydrocarbons or hydrocarbons substituted with halogens or ethers or
heterocyclic
CA 02268590 1999-04-12
27
groups containing nitrogen, oxygen, or sulfur ring atoms. Suitable
hydrocarbons are CS
Cl2alkyl and C3-C,3carbocyclic rings. Particularly preferred cyclic
hydrocarbons
include selected aromatic groups such as phenyl, 1-naphthyl, 2-naphthyl,
indenyl,
acenaphthyl, and fluorenyl and are represented by formulae (III), (IV), (V),
(VI), (VII),
or (VIII) respectively.
A suitable "A" group within the compounds of the present invention is a
phenyl ring represented by formula (III):
R~
R9
R
s
(III)
where R,, Rg and R9 are independently selected from bromine, chlorine,
fluorine,
carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido, nitro,
sulfamyl,
trifluoromethyl, CZ-C,alkanoyloxy, C,-Cbalkyl, C,-Cbalkoxy, CZ-
C,alkoxycarbonyl,
C,-Cbthioalkyl, aryl and N(R,S,R,6) where R,5 and R,6 are independently
selected from
hydrogen, acetyl, methanesulfonyl, and C,-Cbalkyl.
For compounds of formula (I) where X is a direct bond or CHZ, at least
one of R,, Rg and R, is preferably selected from amine (-NR~SR,6, where R~5
and R,6 are
independently hydrogen, acetyl, methanesulfonyl, and C~-C6alkyl), bromine,
chlorine,
fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, nitro, trifluoromethyl,
CZ-C,alkanoyloxy, C,-Cbalkyl, C,-Cbalkoxy, Cz-C,alkylcarbonyl, C,-C6thioalkyl
or aryl
groups. For compounds of formula (I) when X is CH=CH, and R3 and R4 are
hydrogen,
at least one of R,, Rg and R, is preferably a substituent other than hydrogen.
Other suitable "A" groups in compounds of the present invention are
1-naphthyl groups as represented by formula (IV):
CA 02268590 1999-04-12
28
/ \
Rt o Rt t
\ /
(IV)
where R,o and R" are independently selected from bromine, chlorine, fluorine,
carboxy,
hydrogen, hydroxy, hydroxymethyl, methanesulfonamido, vitro, sulfamyl,
trifluoromethyl, CZ-C~alkanoyloxy, C,-Cbalkyl, C,-Cbalkoxy, Cz-
C~alkoxycarbonyl,
C,-Cbthioalkyl, and N(R,S,R,6) where R,5 and R,6 are independently selected
from
hydrogen, acetyl, methanesulfonyl, and C,-Cbalkyl.
Other suitable "A" groups in compounds of the present invention are 2-
naphthyl group as represented by formula (V):
/ \ "
Rto Rt t
\ /
(V)
where R,o and R" are independently selected from bromine, chlorine, fluorine,
carboxy,
hydrogen, hydroxy, hydroxymethyl, methanesulfonamido, vitro, sulfamyl,
trifluoromethyl, CZ-C,alkanoyloxy, C,-Cbalkyl, C,-C6alkoxy, CZ-
C,alkoxycarbonyl,
C,-C6thioalkyl, and N(R,S,R,6) where R,5 and R,6 are independently selected
from
hydrogen, acetyl, methanesulfonyl, and C,-Cbalkyl, as defined above.
Other suitable "A" groups in compounds of the present invention are
aromatic groups represented by formula (VI):
Rt2 \ Z~
(VI)
CA 02268590 1999-04-12
29
where R,2 is selected from bromine, chlorine, fluorine, carboxy, hydrogen,
hydroxy,
hydroxymethyl, methanesulfonamido, nitro, sulfamyl, trifluoromethyl,
CZ-C,alkanoyloxy, C,-Cbalkyl, C,-Cbalkoxy, CZ-C,alkoxycarbonyl, C,-
Cbthioalkyl, and
N(R,S,R,6) where R,5 and R,6 are independently selected from hydrogen, acetyl,
methanesulfonyl, and C,-Cbalkyl; and Z is selected from CH, CH2, O, N and S,
where Z
may be directly bonded to "X" as shown in formula (I) when Z is CH or N, or Z
may be
directly bonded to R" when Z is N, and R" is selected from hydrogen, C,-
Cbalkyl,
C3-CBCycloalkyl, aryl and benzyl.
The aryl groups of formula (VI) are derivatives of indene, indole,
benzofuran, and thianaphthene when Z is methylene, nitrogen, oxygen, and
sulfur,
respectively. Preferred heterocyclic groups of formula (VI) include indole
where Z is
NH, benzofuran where Z is O, and thianaphthene where Z is S. As described
below, in
a preferred embodiment, Z is O, S or N-R", and in a particularly preferred
embodiment
ZisOorS.
Another suitable "A" group in compounds of the present invention are
acenaphthyl groups as represented by formula (VII):
/ \
\ /
(VII)
Still another suitable "A" group in compounds of the present invention is
the fluorenyl group represented by formula (VIII):
(VIII)
CA 02268590 1999-04-12
Preferably, ether side chain component A is an acenapthyl or fluorenyl
group only when X is a direct bond or CHZ. In further preferred embodiments,
the
acenaphthyl group is a 1-acenaphthyl group, and the fluorenyl group is a 9-
fluorenyl
5 group.
As mentioned above, the present invention provides aminocyclohexyl
ethers represented by formula (I). In a preferred embodiment X is (CHZ)-Y. For
these
embodiments, Y is preferably a direct bond, an oxygen atom, or a sulfur atom.
In a
particularly preferred embodiment, Y is a direct bond or an oxygen atom. In
another
10 preferred embodiment Y is a direct bond and X is C(R6,R,4), where R6 and
R,4 are as
defined above. In another preferred embodiment, where X is C(R,3)=CH, R,3 is a
hydrogen atom. For these embodiments, R3 and R4 are preferably independently
attached to the cyclohexane ring at the 4- or 5- positions.
In a preferred embodiment, the invention provides compounds having
15 formula (IX), or a solvate or pharmaceutically acceptable salt thereof:
~X~O R~
'R2
R4
(IX)
wherein, independently at each occurrence,
20 X is selected from a direct bond, -CH=CH- and -C(R.6,R,4)-Y-;
Y is selected from a direct bond, O and S; and
R,, R2, R3, R4, R6, R,, R8, R9, R,o, R", R,z, R,4, A and Z are defined as
above for compounds of formula (I).
CA 02268590 1999-04-12
31
In another preferred embodiment, the invention provides a compound
having formula (X), or a solvate or pharmaceutically acceptable salt thereof:
A ~
X/ \O R~
N~
R2
(X)
wherein, independently at each occurrence,
X is selected from a direct bond, -CH=CH- and -C(R6,R,4)-Y-;
Y is selected from a direct bond, O, and S;
R,, R2, R6 and R~4 are defined as above for compounds of formula (I);
R3 and R4 are independently attached to the cyclohexane ring at the 4- or
5-positions, and are independently selected from hydrogen and C~-Cbalkoxy; and
A is selected from CS-C~Zalkyl, C3-Cgcycloalkyl, and any of formulae
(III), (IV), (V), and (VI) as above for compounds of formula (I), wherein Z,
R,, Rg, Rg,
R,o, R" and R~Z are defined as above for compounds of formula (I).
In another preferred embodiment, the invention provides compounds
having formula (XI), or a solvate or pharmaceutically acceptable salt thereof:
CA 02268590 1999-04-12
32
O
A/ R~
N
\ R2
(XI)
wherein, independently at each occurrence,
R, and R2 are defined as above for compounds of formula (I);
R3 and R4 are independently attached to the cyclohexane ring at the 4- or
5-positions, and are independently selected from hydrogen and methoxy; and
A is selected from CS-C,zalkyl, C3-CBCycloalkyl, and any of formulae
(III), (IV), (V), and (VI) as above for compounds of formula (I), wherein Z,
R,, Rg, R,,
R,o, R" and R,2 are defined as above for compounds of formula (I).
In another preferred embodiment, the invention provides compounds of
formula (XII), or a solvate or pharmaceutically acceptable salt thereof:
A
1 1
N
\ R2
R4
R3
(XII)
wherein, independently at each occurrence,
R, and Rz are defined as above for compounds of formula (I);;
CA 02268590 1999-04-12
33
R3 and R4 are independently attached to the cyclohexane ring at the 4- or
5-positions, and are independently selected from hydrogen and methoxy; and
A is selected from CS-C,Zalkyl, C3-Cgcycloalkyl, and any of formulae
(III), (IV), (V), and (VI) as above for compounds of formula (I), wherein Z,
R~, R8, R9,
R,o, R" and R,z are defined as above for compounds of formula (I).
In another preferred embodiment, the invention provides compounds of
formula (XIII), or a solvate or pharmaceutically acceptable salt thereof:
A ~
x~0 R~
N
'R2
R3
(XIII)
wherein, independently at each occurrence,
X is selected from a direct bond and -CH=CH-;
R, and RZ are defined as above for compounds of formula (I);;
I 5 R3 and R4 are independently attached to the cyclohexane ring at the 4- or
5-positions, and are independently selected from hydrogen and methoxy; and
A is selected from C3-Cgcycloalkyl and any of formulae (III), (IV), (V),
(VI), (VII) and (VIII) as above for compounds of formula (I), where Rg and R9
are
defined as above for compounds of formula (I); R,, R,o, R" and R,2 are
hydrogen, and Z
is selected from O, S and N-R,~ where R" is selected from hydrogen and methyl;
with
the proviso that A may be selected from formulae (VII) and (VIII) only when X
is a
direct bond.
In another preferred embodiment, the invention provides compounds
having formula (XIV), or a solvate or pharmaceutically acceptable salt
thereof:
CA 02268590 1999-04-12
34
O
A~ O R~
\ R2
(XIV)
wherein, independently at each occurrence,
R, and RZ are defined as above for compounds of formula (I);
A is selected from any of formulae (III), (IV), (V) and (VI) as above for
compounds of formula (I), wherein R~, R,o, R", and R,z, are hydrogen, Rg and
R9 are
independently selected from hydrogen, hydroxy, fluorine, chlorine, bromine,
methanesulfonamido, methanoyloxy, methoxycarbonyl, nitro, sulfamyl,
thiomethyl,
trifluoromethyl, methyl, ethyl, methoxy, ethoxy and NH2, with the proviso that
at least
one of R8 and R, is not hydrogen; and Z is selected from O and S.
In another preferred embodiment, the invention provides compounds
having formula (XV), or a solvate or pharmaceutically acceptable salt thereof:
A
O R~
\ R2
(XV)
wherein, independently at each occurrence,
R, and RZ are defined as above for compounds of formula (I); and
A is selected from any of formulae (III), (IV), (V) and (VI) as defined
above for compounds of formula (I), wherein R,, R,o, R", and R,2, are
hydrogen, Rg and
CA 02268590 1999-04-12
R9 are independently selected from hydrogen, hydroxy, fluorine, chlorine,
bromine,
methanesulfonamido, methanoyloxy, methoxycarbonyl, nitro, sulfamyl,
thiomethyl,
trifluoromethyl, methyl, ethyl, methoxy, ethoxy and NHZ, with the proviso that
at least
one of R8 and R9 is not hydrogen; and Z is selected from O and S.
5 In another preferred embodiment, the invention provides compounds
having formula (XVI), or a solvate or pharmaceutically acceptable salt
thereof:
~X~O R~
R2
(XVI)
10 wherein, independently at each occurrence,
X is selected from a direct bond, traps-CH=CH-, -CHZ- and -CHZ-O-;
R, and Rz are both methoxyethyl or, when taken together with the
nitrogen atom to which they are attached, complete a ring selected from
pyrrolidinyl,
ketopyrrolidinyl, acetoxypyrrolidinyl, hydroxypyrrolidinyl, thiazolidinyl,
piperidinyl,
15 ketopiperidinyl, acetylpiperazinyl, 1,4-dioxa-7-azaspiro[4.4]non-7-yl,
hexahydroazepinyl, morpholinyl, N-methylpiperazinyl and 3-
azabicyclo[3.2.2]nonanyl;
and
A is selected from cyclohexyl, monochlorophenyl, 2,6-dichlorophenyl,
3,4-dichlorophenyl, 2-bromophenyl, 2,4-dibromophenyl, 3-bromophenyl,
20 4-bromophenyl, 1-naphthyl, 2-naphthyl, 3-benzo(b)thiophenyl, 4-
benzo(b)thiophenyl,
(2-trifluoromethyl)phenyl, 2,4-di(trifluoromethyl)phenyl, and (4-
trifluoromethyl)phenyl.
The following are further preferred compounds of the present invention:
CA 02268590 1999-04-12
36
(1R,2R)/(1S,2S)-[2-(4-morpholinyl)-1-(2- ,O / \
naphthenethoxy)]cyclohexane
N \
O
O
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-( 1-
naphthenethoxy)]cyclohexane N \
O
O
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-(4-
bromophenethoxy)]cyclohexane N \ Br
O
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-[2-(2-
naphthoxy)ethoxy]]cyclohexane N
O
Br
O
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-[2-(4- ~ ~O \
bromophenoxy)ethoxy]]cyclohexane N
O
/ \
~O\/\ \
O
CA 02268590 1999-04-12
37
~O / OMe
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-(3,4- \
dimethoxyphenethoxy)]cyclohexane N OMe
O
( 1 R,2R)/( 1 S,2S)-[2-( 1-pyrrolidinyl)-1-( 1-
naphthenethoxy)]cyclohexane
N
~O
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-(2-
(benzo[b]thlophen-3-yl)]cyclohexane N S
O
O S
(1R,2R)/(1S,2S)-[2-(4-morpholinyl)-1-(2- ~ /
N
(benzo[b]thiophen-4-yl)]cyclohexane
O
O Br
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-(3-
N \
bromophenethoxy)]cyclohexane
O
CA 02268590 1999-04-12
38
Br
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-(2-
bromophenethoxy)]cyclohexane
N
O
OMe
( 1 R,2R)/( 1 S,2S)-[2-(4-morpholinyl)-1-(3- O
OMe
(3,4-dimethoxyphenyl)propoxy)]cyclohexane
'N
O
O
/ \
( 1 R,2R)/( 1 S,2S)-[2-[bis(2-
N
methoxyethyl)aminyl]-1-(2-
OMe
naphthenethoxy)]cyclohexane
OMe
.O / CI
( 1 R,2R)/( 1 S,2S)-2-(4-morpholinyl)-1-(3,4-
dichlorophenethoxy)cyclohexane N~ C I
(1R,2R)/(1S,2S)-2-(3-ketopyrrolidinyl)-1-(1- O
naphthenethoxy)cyclohexane
N~ O
CA 02268590 1999-04-12
39
.O
(1R,2R)/(1S,2S)-2-(1-acetylpiperazinyl)-1- ' N
(2-naphthenethoxy)cyclohexane ~ C H
3
O
CI
(1R,2R)/(1S,2S)-2-(3-ketopyrrolidinyl)-1- 'O i
(2,6-dichlorophenethoxy)cyclohexane CI~
.HCI
( 1 R,2R)/( 1 S,2S)-2-[ 1,4-dioxa-7- O
/
azaspiro[4.4]non-7-yl]-1-(1-
naphthenethoxy)cyclohexane ~ N~\\~O
CF3
(1R,2S)/(1S,2R)-2-(4-morpholinyl)-1-[(2- 'O i
trifluoromethyl)phenethoxy]cyclohexane
~' N
monohydrochloride ~ O . HC I
(1R,2R)/(1S,2S)-2-(3-ketopyrrolidinyl)-1-[3- O
(cyclohexyl)propoxy]cyclohexane ~. N
.HCI
monohydrochloride
O
(1R,2R)/(1S,2S)-2-(3-acetoxypyrrolidinyl)-1- O
(1-naphthenethoxy)cyclohexane I /
'~N
monohydrochloride
.HCI
O
CA 02268590 1999-04-12
CI
(1R,2R)/(1S,2S)-2-(4-morpholinyl)-1-[(2,6-O
dichlorophenyl)methoxy]cyclohexanea CI
N
monohydrochloride ~O .HCI
CI
( 1 R,2R)/( I S,2S)-2-(3-ketopyrrolidinyl)-1-O
[(2,6-dichlorophenyl)methoxy]cyclohexanea CI
N
monohydrochloride
.HCI
O
CI
(1R,2R)/(1S,2S)-2-(3-hydroxypyrrolidinyl)-'O
1-(2,6-dichlorophenethoxy)cyclohexaneCI
N
monohydrochloride ~~"~~.OH .HCI
i
( 1 R,2R)/( 1 S,2S)-2-(3-ketopyrrolidinyl)-1-
(2,2-diphenylethoxy)cyclohexane -O
monohydrochloride ' N
O .HCI
CI
( I R,2R)/( 1 S,2S)-2-(3-thiazolidinyl)-1-(2,6- O
dichlorophenethoxy)cyclohexane ''N CI
monohydrochloride ~~ .HCI
i
1R,2S / 1S,2R -2- 3-keto rrolidin 1 -1- 1
( )( ) ( pY Y) ( - 'O i
naphthenethoxy)cyclohexane w
N~ O
monohydrochloride .HCI
Outline of Method of Preparation of Compounds of the Invention
The aminocyclohexyl ether compounds of the present invention contain
amino and ether sidechains disposed in a 1,2 arrangement on a cyclohexane
ring.
CA 02268590 1999-04-12
41
Accordingly, the amino and ether sidechains may be disposed in either a cis or
traps
relationship, relative to one another and the plane of the cyclohexane ring.
The present
invention provides synthetic methodology whereby cis or traps compounds may be
prepared.
Traps compounds of the present invention may be prepared in analogy
with known synthetic methodology (see, e.g., Shanklin, Jr. et al., U.S.
Patent,
5,130,309). Figure 1 outlines the preparation of a traps compound of the
invention,
where this preparation is more fully described in Example 1. As outlined in
Figure 1,
the preparation of a traps compound of the invention may be achieved by
following a
four step procedure.
In a first step (denoted "i)" in Figure 1 ), cyclohexene epoxide undergoes
a ring-opening reaction with an amine. See, e.g., Szmuszkovicz, U.S. Patent
4,145,435.
While the reaction can occur at room temperature, typically elevated
temperature is
preferred in order to drive the reaction to completion in a commercially
desirable length
of time. The reaction is typically conducted in a solvent, such as water, and
the reflux
temperature of the solvent provides a suitable temperature. Equal molar
amounts of the
amine and cyclohexene epoxide typically provide satisfactory results. In any
event, the
amine nitrogen reacts with the epoxide group to form a 1-hydroxy 2-amino
cyclohexane, where the hydroxy and amine groups are typically disposed in a
traps
relationship. A wide variety of amine compounds and substituted cyclohexene
oxides
may be employed in this general reaction, and Figure 1 illustrates this
reaction in the
instance where the amine is morpholine and the cyclohexene oxide is
unsubstituted.
For other amines or substituted cyclohexene epoxides that may contain other
reactive
functional groups, appropriate protection groups are introduced prior to step
i) being
carried out. Suitable protecting groups are set forth in, for example, Greene,
"Protective
Groups in Organic Chemistry", John Wiley & Sons, New York NY (1991).
In a second step (denoted "ii)" in Figure 1 ) the hydroxy group that was
derived from the epoxide, is converted into an activated form. An "activated
form" as
used herein means that the hydroxy group is converted into a good leaving
group. The
leaving group illustrated in Figure 1 is a mesylate group, and that is a
preferred leaving
CA 02268590 1999-04-12
42
group. However, the hydroxy group could be converted into other leaving groups
according to procedures well known in the art. In a typical reaction, the
aminocyclohexanol compound is treated with methanesulfonyl chloride in the
presence
of a base, such as triethylamine as shown in Figure 1. The reaction is
satisfactorily
conducted at about 0°C. An excess of the methanesulfonyl chloride,
relative to the
aminocyclohexanol, is typically preferred in order to maximally convert the
more
valuable aminocyclohexanol into the activated form. For some other
aminocyclohexanol compounds, it may be necessary to introduce appropriate
protection
groups prior to step ii) being performed. Suitable protecting groups are set
forth in, for
example, Greene, "Protective Groups in Organic Chemistry", John Wiley & Sons,
New
York NY ( 1991 ).
In a third step (denoted "iii)" in Figure 1 ) an alcohol is reacted with a
strong base to provide an alkoxide salt. Conversion of an alcohol to an
alkoxide (also
known as an alcoholate) using strong base is a general reaction, and will work
with a
wide variety of hydroxy-containing compounds. In some instances, the alcohol
compound may have other reactive functional groups that are desirably
protected prior
to contact of the alcohol with strong base. Suitable protecting groups are set
forth in,
for example, Greene, "Protective Groups in Organic Chemistry", John Wiley &
Sons,
New York NY (1991). Such alcohols are either commercially available or may be
obtained by procedures described in the art or adapted therefrom, where
suitable
procedures may be identified through the Chemical Abstracts and Indices
therefor, as
developed and published by the American Chemical Society.
In a fourth step (denoted "iv)" in Figure 1 ), the alcoholate of step "iii)"
is
reacted with the activated aminocyclohexanol of step "ii)". Thus, generally
stated,
compounds of the present invention may be prepared by reacting an activated
form of
the appropriate 1,2-aminocyclohexanol (1 mol) with an alcoholate (1.25 mol)
prepared
by treatment of the selected alcohol (1.25 mol) with, for example, sodium
hydride (1.3
mol). The 1,2-aminocyclohexanol (1 mol) can be activated by forming the
corresponding mesylate, in the presence of methanesulfonyl chloride (1.25 mol)
and
triethylamine (1.5 mol). The mesylate is added quickly to the alcoholate, in a
suitable
CA 02268590 1999-04-12
43
solvent such as dimethylformamide. The reaction temperature is monitored
carefully in
order to avoid undesired side-reactions such as (3-elimination. In general, a
reaction
temperature of 80-90°C for 2 hours is typically suitable to form
compounds of the
invention. When the reaction has proceeded to substantial completion, the
desired
product is recovered from the reaction mixture by conventional organic
chemistry
techniques, and is purified generally by column chromatography followed by
recrystallisation. Protective groups may be removed at the appropriate stage
of the
reaction sequence. Suitable methods are set forth in, for example, Greene,
"Protective
Groups in Organic Chemistry", John Wiley & Sons, New York NY (1991).
The reaction sequence described above (and shown in Figure 1 )
generates the aminocyclohexyl ether as the free base. The pure enantiomeric
forms can
be obtained by preparative chiral HPLC. The free base may be converted, if
desired, to
the monohydrochloride salt by known methodologies, and subsequently, if
desired, to
other acid addition salts by reaction with inorganic or organic salts. Acid
addition salts
can also be prepared metathetically by reacting one acid addition salt with an
acid
which is stronger than that of the anion of the initial salt.
Cis or traps compounds of the invention may be prepared according to
the chemistry outlined in Figure 2. As shown in Figure 2, 1, 2-
aminocyclohexanones
may be prepared by Swern oxidation of the corresponding traps-1,
2-aminocyclohexanol compounds (which may be prepared as described above) using
oxalyl chloride/dimethyl sulfoxide (see, e.g., Synthesis 1980, 165).
Subsequent
reduction of the aminocyclohexanone with lithium aluminum hydride or sodium
borohydride provides a mixture of cis- and traps-aminocyclohexanols. The
mixture of
aminoalcohols may be esterified with an appropriate carboxylic acid by
azeotropic
distillation in toluene in the presence of a catalytic amount of p-
toluenesulfonic acid, to
provide a diastereomeric mixture of cis- and traps-esters. The mixture of
diastereomeric esters can be separated by preparative chromatography by one of
ordinary skill in the art. The racemic cis- or traps ester preparation could
then be
reduced with sodium borohydride in the presence of Lewis acid to the
corresponding
racemic cis- or traps-ether (see, e.g., J. Org. Chem. 25, 875, 1960 and
Tetrahedron 18,
CA 02268590 1999-04-12
44
953, 1962). The racemic cis-ether can be resolved by preparative chiral HPLC
as
discussed above for the traps-compound.
Alternatively, cis and traps compounds of the invention may be prepared
according to the chemistry outlined in Figure 3. As shown in Figure 3,
cyclohexene
oxide can react with an alcohol (ROH) in the present of Mg(C104)Z (see, e.g.,
M. Chini
et al., Synlett, 673-676, 1992) to provide 1,2-hydroxycyclohexyl ethers.
Oxidation with
pyridinium dichromate (see, e.g., R. Oshima et al., J. Org. Chem., 50, 2613-
2621, 1985)
yielded the corresponding 1,2-alkoxycyclohexanone. Subsequent reductive
amination
(R. F. Borch et al., J. Am. Chem. Soc., 93(12), 2897-2904, 1971) provides a
mixture of
cis- and traps-aminocyclohexyl ethers. The mixture of diastereomeric ethers
can be
separated by chromatography by one of ordinary skill in the art. The racemic
cis- or
traps-ether so prepared could then be resolved by classical recrystallization
methods
well known in the art or by preparative chiral HPLC to provide the individual
enantiomer: traps-( 1 R,2R), traps-( 1 S,2S), cis-( 1 R,2S) or cis-( 1 S,2R)
aminoethers.
The synthetic procedures described herein, especially when taken with
the general knowledge in the art, provide sufficient guidance to those of
ordinary skill
in the art to perform the synthesis, isolation, and purification of the
compounds of the
present invention.
Compositions and Modes of Administration
In another embodiment, the present invention provides compositions
which include a cyclohexylamine compound as described above in admixture or
otherwise in association with one or more inert carriers, excipients and
diluents, as well
as optional ingredients if desired. These compositions are useful as, for
example, assay
standards, convenient means of making bulk shipments, or pharmaceutical
compositions. An assayable amount of a compound of the invention is an amount
which is readily measurable by standard assay procedures and techniques as are
well
known and appreciated by those skilled in the art. Assayable amounts of a
compound
of the invention will generally vary from about 0.001 wt% to about 75 wt% of
the entire
weight of the composition. Inert carriers include any material which does not
degrade
CA 02268590 1999-04-12
or otherwise covalently react with a compound of the invention. Examples of
suitable
inert carriers are water; aqueous buffers, such as those which are generally
useful in
High Performance Liquid Chromatography (HPLC) analysis; organic solvents such
as
acetonitrile, ethyl acetate, hexane and the like (which are suitable for use
in in vitro
5 diagnostics or assays, but typically are not suitable for administration to
a warm-
blooded animal); and pharmaceutically acceptable carriers, such as
physiological saline.
Thus, the present invention provides a pharmaceutical or veterinary
composition (hereinafter, simply referred to as a pharmaceutical composition)
containing a cyclohexylamine compound as described above, in admixture with a
10 pharmaceutically acceptable carrier, excipient or diluent. The invention
further
provides a pharmaceutical composition containing an effective amount of a
cyclohexylamine compound as described above, in association with a
pharmaceutically
acceptable carrier.
The pharmaceutical compositions of the present invention may be in any
15 form which allows for the composition to be administered to a patient. For
example,
the composition may be in the form of a solid, liquid or gas (aerosol).
Typical routes of
administration include, without limitation, oral, topical, parenteral,
sublingual, rectal,
vaginal, and intranasal. The term parenteral as used herein includes
subcutaneous
injections, intravenous, intramuscular, epidural, intrasternal injection or
infusion
20 techniques. Pharmaceutical composition of the invention are formulated so
as to allow
the active ingredients contained therein to be bioavailable upon
administration of the
composition to a patient. Compositions that will be administered to a patient
take the
form of one or more dosage units, where for example, a tablet, capsule or
cachet may be
a single dosage unit, and a container of cyclohexylamine compound in aerosol
form
25 may hold a plurality of dosage units.
Materials used in preparing the pharmaceutical compositions should be
pharmaceutically pure and non-toxic in the amounts used. The inventive
compositions
may include one or more compounds (active ingredients) known for a
particularly
desirable effect. For instance, epinephrine may be combined with an
aminocyclohexyl
30 ether compound of the invention, to provide a composition useful to induce
local
CA 02268590 1999-04-12
46
anesthesia. It will be evident to those of ordinary skill in the art that the
optimal dosage
of the active ingredients) in the pharmaceutical composition will depend on a
variety of
factors. Relevant factors include, without limitation, the type of subject
(e.g., human),
the particular form of the active ingredient, the manner of administration and
the
composition employed.
In general, the pharmaceutical composition includes a cyclohexylamine
compound as described herein, in admixture with one or more carriers. The
carriers)
may be particulate, so that the compositions are, for example, in tablet or
powder form.
The carriers) may be liquid, with the compositions being, for example, an oral
syrup or
injectable liquid. In addition, the carriers) may be gaseous, so as to provide
an aerosol
composition useful in, e.g., inhalatory administration.
When intended for oral administration, the composition is preferably in
either solid or liquid form, where semi-solid, semi-liquid, suspension and gel
forms are
included within the forms considered herein as either solid or liquid.
As a solid composition for oral administration, the composition may be
formulated into a powder, granule, compressed tablet, pill, capsule, cachet,
chewing
gum, wafer, lozenges, or the like form. Such a solid composition will
typically contain
one or more inert diluents or edible carriers. In addition, one or more of the
following
adjuvants may be present: binders such as syrups, acacia, sorbitol,
polyvinylpyrrolidone, carboxymethylcellulose, ethyl cellulose,
microcrystalline
cellulose, gum tragacanth or gelatin, and mixtures thereof; excipients such as
staxch,
lactose or dextrins, disintegrating agents such as alginic acid, sodium
alginate,
Primogel, corn starch and the like; lubricants such as magnesium stearate or
Sterotex;
fillers such as lactose, mannitols, starch, calcium phosphate, sorbitol,
methylcellulose,
and mixtures thereof; lubricants such as magnesium stearate, high molecular
weight
polymers such as polyethylene glycol, high molecular weight fatty acids such
as stearic
acid, silica, wetting agents such as sodium lauryl sulfate, glidants such as
colloidal
silicon dioxide; sweetening agents such as sucrose or saccharin, a flavoring
agent such
as peppermint, methyl salicylate or orange flavoring, and a coloring agent.
CA 02268590 1999-04-12
47
When the composition is in the form of a capsule, e.g., a gelatin capsule,
it may contain, in addition to materials of the above type, a liquid carrier
such as
polyethylene glycol or a fatty oil.
The composition may be in the form of a liquid, e.g., an elixir, syrup,
solution, aqueous or oily emulsion or suspension, or even dry powders which
may be
reconstituted with water and/or other liquid media prior to use. The liquid
may be for
oral administration or for delivery by injection, as two examples. When
intended for
oral administration, preferred compositions contain, in addition to the
present
compounds, one or more of a sweetening agent, thickening agent, preservative
(e.g.,
alkyl p-hydoxybenzoate), dye/colorant and flavor enhancer (flavorant). In a
composition intended to be administered by injection, one or more of a
surfactant,
preservative (e.g., alkyl p-hydroxybenzoate), wetting agent, dispersing agent,
suspending agent (e.g., sorbitol, glucose, or other sugar syrups), buffer,
stabilizer and
isotonic agent may be included. The emulsifying agent may be selected from
lecithin or
sorbitol monooleate.
The liquid pharmaceutical compositions of the invention, whether they
be solutions, suspensions or other like form, may include one or more of the
following
adjuvants: sterile diluents such as water for injection, saline solution,
preferably
physiological saline, Ringer's solution, isotonic sodium chloride, fixed oils
such as
synthetic mono or digylcerides which may serve as the solvent or suspending
medium,
polyethylene glycols, glycerin, propylene glycol or other solvents;
antibacterial agents
such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid
or sodium
bisulfate; chelating agents such as ethylenediaminetetraacetic acid; buffers
such as
acetates, citrates or phosphates and agents for the adjustment of tonicity
such as sodium
chloride or dextrose. The parenteral preparation can be enclosed in ampoules,
disposable syringes or multiple dose vials made of glass or plastic.
Physiological saline
is a preferred adjuvant. An injectable pharmaceutical composition is
preferably sterile.
A liquid compositions intended for either parenteral or oral
administration should contain an amount of the inventive compound such that a
suitable
dosage will be obtained. Typically, this amount is at least 0.01% of a
compound of the
CA 02268590 1999-04-12
48
invention in the composition. When intended for oral administration, this
amount may
be varied to be between 0.1 and about 70% of the weight of the composition.
Preferred
oral compositions contain between about 4% and about 50% of the active
cyclohexylamine compound. Preferred compositions and preparations according to
the
present invention are prepared so that a parenteral dosage unit contains
between 0.01 to
10% by weight of active compound.
The pharmaceutical composition may be intended for topical
administration, in which case the carrier may suitably comprise a solution,
emulsion,
ointment, cream or gel base. The base, for example, may comprise one or more
of the
following: petrolatum, lanolin, polyethylene glycols, bee wax, mineral oil,
diluents
such as water and alcohol, and emulsifiers and stabilizers. Thickening agents
may be
present in a pharmaceutical composition for topical administration. If
intended for
transdermal administration, the composition may include a transdermal patch or
iontophoresis device. Topical formulations may contain a concentration of the
inventive compound of from about 0.1 to about 25% w/v (weight per unit
volume).
The composition may be intended for rectal administration, in the form,
e.g., of a suppository which will melt in the rectum and release the drug. The
composition for rectal administration may contain an oleaginous base as a
suitable
nonirritating excipient. Such bases include, without limitation, lanolin,
cocoa butter and
polyethylene glycol. Low-melting waxes are preferred for the preparation of a
suppository, where mixtures of fatty acid glycerides and/or cocoa butter are
suitable
waxes. The waxes may be melted, and the cyclohexylamine compound is dispersed
homogeneously therein by stirring. The molten homogeneous mixture is then
poured
into convenient sized molds, allowed to cool and thereby solidify.
The composition may include various materials which modify the
physical form of a solid or liquid dosage unit. For example, the composition
may
include materials that form a coating shell around the active ingredients. The
materials
which form the coating shell are typically inert, and may be selected from,
for example,
sugar, shellac, and other enteric coating agents. Alternatively, the active
ingredients
may be encased in a gelatin capsule or cachet.
CA 02268590 1999-04-12
49
The composition in solid or liquid form may include an agent which
binds to the cyclohexylamine compound and thereby assists in the delivery of
the active
components. Suitable agents which may act in this capacity include a
monoclonal or
polyclonal antibody, a protein or a liposome.
The pharmaceutical composition of the present invention may consist of
gaseous dosage units, e.g., it may be in the form of an aerosol. The term
aerosol is used
to denote a variety of systems ranging from those of colloidal nature to
systems
consisting of pressurized packages. Delivery may be by a liquefied or
compressed gas
or by a suitable pump system which dispenses the active ingredients. Aerosols
of
compounds of the invention may be delivered in single phase, bi-phasic, or tri-
phasic
systems in order to deliver the active ingredient(s). Delivery of the aerosol
includes the
necessary container, activators, valves, subcontainers, and the like, which
together may
form a kit. Preferred aerosols may be determined by one skilled in the art,
without
undue experimentation.
Whether in solid, liquid or gaseous form, the pharmaceutical
composition of the present invention may contain one or more known
pharmacological
agents used in methods for either modulating ion channel activity in a warm-
blooded
animal or for modulating ion channel activity in vitro, or used in the
treatment of
arrhythmia, diseases of the central nervous system, convulsion, epileptic
spasms,
depression, anxiety, schizophrenia, Parkinson's disease, respiratory
disorders, cystic
fibrosis, asthma, cough, inflammation, arthritis, allergies, gastrointestinal
disorders,
urinary incontinence, irritable bowel syndrome, cardiovascular diseases,
cerebral or
myocardial ischemias, hypertension, long-QT syndrome, stroke, migraine,
ophthalmic
diseases, diabetes mellitus, myopathies, Becker's myotonia, myasthenia gravis,
paramyotonia congentia, malignant hyperthermia, hyperkalemic periodic
paralysis,
Thomsen's myotonia, autoimmune disorders, graft rejection in organ
transplantation or
bone marrow transplantation, heart failure, hypotension, Alzheimer's disease
and other
metal disorders, and alopecia. Other agents known to cause libido enhancement,
local
analgesia or anesthesia may be combined with compounds of the present
invention.
CA 02268590 1999-04-12
The pharmaceutical compositions may be prepared by methodology well
known in the pharmaceutical art. The aminocyclohexyl compounds of the
invention
may be in the form of a solvate in a pharmaceutically acceptable solvent such
as water
or physiological saline. Alternatively, the compounds may be in the form of
the free
5 base or in the form of a pharmaceutically acceptable salt such as the
hydrochloride,
sulfate, phosphate, citrate, fumarate, methanesulfonate, acetate, tartrate,
maleate, lactate,
mandelate, salicylate, succinate and other salts known in the art. The
appropriate salt
would be chosen to enhance bioavailability or stability of the compound for
the
appropriate mode of employment (e.g., oral or parenteral routes of
administration).
10 A composition intended to be administered by injection can be prepared
by combining the cyclohexylamine compound with water, and preferably buffering
agents, so as to form a solution. The water is preferably sterile pyrogen-free
water. A
surfactant may be added to facilitate the formation of a homogeneous solution
or
suspension. Surfactants are compounds that non-covalently interact with the
15 cyclohexylamine compound so as to facilitate dissolution or homogeneous
suspension
of the cyclohexylamine compound in the aqueous delivery system. Surfactants
are
desirably present in aqueous compositions of the invention because the
cyclohexylamine compounds of the present invention are typically hydrophobic.
Other
carriers for injection include, without limitation, sterile peroxide-free
ethyl oleate,
20 dehydrated alcohols, propylene glycol, as well as mixtures thereof.
Suitable pharmaceutical adjuvants for the injecting solutions include
stabilizing agents, solubilizing agents, buffers, and viscosity regulators.
Examples of
these adjuvants include ethanol, ethylenediaminetetraacetic acid (EDTA),
tartrate
buffers, citrate buffers, and high molecular weight polyethylene oxide
viscosity
25 regulators. These pharmaceutical formulations may be injected
intramuscularly,
epidurally, intraperitoneally, or intravenously.
CA 02268590 1999-04-12
$1
Pharmacological Testing
As noted above, the present invention provides for utilizing the
compounds described above in in vitro and in vivo methods. In one embodiment,
ion
channels, such as cardiac sodium channels, are blocked in vitro or in vivo.
Ion channels are ubiquitous membrane proteins in the cells of warm-
blooded animals such as mammals. Their critical physiological roles include
control of
the electrical potential across the membrane, mediation of ionic and fluid
balance,
facilitation of neuromuscular and neuronal transmission, rapid transmembrane
signal
transduction, and regulation of secretion and contractility.
Accordingly, compounds that are capable of modulating the activity or
function of the appropriate ion channels will be useful in treating or
preventing a variety
of diseases or disorders caused by defective or inadequate function of the ion
channels.
The compounds of the invention are found to have significant activity in
modulating ion
channel activity both in vivo and in vitro.
Thus, the present invention provides for methods of treating a disease or
condition in a warm-blooded animal suffering from or having the disease or
condition,
and/or preventing a disease or condition from arising in a warm-blooded
animal,
wherein a therapeutically effective amount of a compound of formula (I), or a
composition containing a compound of formula (I) is administered to a warm-
blooded
animal in need thereof. The diseases and conditions to which the compounds,
compositions and methods of the present invention may be applied as follows:
arrhythmia, diseases of the central nervous system, convulsion, epileptic
spasms,
depression, anxiety, schizophrenia, Parkinson's disease, respiratory
disorders, cystic
fibrosis, asthma, cough, inflammation, arthritis, allergies, gastrointestinal
disorders,
urinary incontinence, irritable bowel syndrome, cardiovascular diseases,
cerebral or
myocardial ischemias, hypertension, long-QT syndrome, stroke, migraine,
ophthalmic
diseases, diabetes mellitus, myopathies, Becker's myotonia, myasthenia gravis,
paramyotonia congentia, malignant hyperthermia, hyperkalemic periodic
paralysis,
Thomsen's myotonia, autoimmune disorders, graft rejection in organ
transplantation or
CA 02268590 1999-04-12
52
bone marrow transplantation, heart failure, hypotension, Alzheimer's disease
or other
mental disorder, and alopecia.
Furthermore, the present invention provides a method for producing
local analgesia or anesthesia in a warm-blooded animal which includes
administering to
a warm-blooded animal in need thereof an effective amount of a compound of
formula
(I) or a pharmaceutical composition containing a compound of formula (I).
These
methods may be used to relieve or forestall the sensation of pain in a warm-
blooded
animal.
Furthermore, the present invention provides a method wherein a
preparation that contains ion channels is contacted with, or a warm-blooded
animal
(e.g., a mammal, such as a human) is administered an effective amount of an
aminocyclohexyl ether compound of the invention. Suitable preparations
containing
cardiac sodium channels include cells isolated from cardiac tissue as well as
cultured
cell lines. The step of contacting includes, for example, incubation of ion
channels with
a compound under conditions and for a time sufficient to permit modulation of
the
activity of the channels by the compound.
In another embodiment, the compounds described above are provided for
treating arrhythmia. As used herein, "treating arrhythmia" refers to both
therapy for
arrhythmia and for the prevention of arrhythmias occurring in a heart that is
susceptible
to arrhythmia. An effective amount of a composition of the present invention
is used to
treat arrhythmia in a warm-blooded animal, such as a human. Methods of
administering
effective amounts of antiarrhythmic agents are well known in the art and
include the
administration of an oral or parenteral dosage form. Such dosage forms
include, but are
not limited to, parenteral dosage form. Such dosage forms include, but are not
limited
to, parenteral solutions, tablets, capsules, sustained release implants, and
transdermal
delivery systems. Generally, oral or intravenous administration is preferred.
The
dosage amount and frequency are selected to create an effective level of the
agent
without harmful effects. It will generally range from a dosage of from about
0.1 to
about 100 mg/kg/day, and typically from about 0.1 to 10 mg/kg where
administered
orally or intravenously for antiarrhythmic effect.
CA 02268590 1999-04-12
53
Administration of compositions of the present invention may be carried
out in combination with the administration of other agents. For example, it
may be
desired to administer an opioid antagonist, such as naloxone, if a compound
exhibits
opioid activity where such activity may not be desired. The naloxone may
antagonize
opioid activity of the administered compound without adverse interference with
the
antiarrhythmic activity. As another example, an aminocyclohexyl ether compound
of
the invention may be co-administered with epinephrine in order to include
local
anesthesia.
In order to assess whether a compound has a desired pharmacological
activity with the present invention, it is subjected to a series of tests. The
precise test to
employ will depend on the physiological response of interest. The published
literature
contains numerous protocols for testing the efficacy of a potential
therapeutic agent, and
these protocols may be employed with the present compounds and compositions.
For example, in connection with treatment or prevention of arrhythmia, a
series of four tests may be conducted. In the first of these tests, a compound
of the
present invention is given as increasing (doubling with each dose) intravenous
boluses
every 8 minutes to a pentobarbital anesthetized rat. The effects of the
compound on
blood pressure, heart rate and the ECG are measured 30 seconds, 1, 2, 4 and 8
minutes
after each dose. Increasing doses are given until the animal dies. The cause
of death is
identified as being of either respiratory or cardiac origin. This test gives
an indication
as to whether the compound is modulating the activity of sodium channels
and/or
potassium channels, and in addition gives information about acute toxicity.
The indices
of sodium channel blockade are increasing P-R interval and QRS widening of the
ECG.
Potassium channel blockade results in Q-T interval prolongation of the ECG.
A second test involves administration of a compound as an infusion to
pentobarbital anesthetized rats in which the left ventricle is subjected to
electrical
square wave stimulation performed according to a preset protocol described in
further
detail below. This protocol includes the determination of thresholds for
induction of
extrasystoles and ventricular fibrillation. In addition, effects on electrical
refractoriness
are assessed by a single extra beat technique. In addition effects on blood
pressure,
CA 02268590 1999-04-12
54
heart rate and the ECG are recorded. In this test, sodium channel Mockers
produce the
ECG changes expected from the first test. In addition, sodium channel Mockers
also
raise the thresholds for induction of extrasystoles and ventricular
fibrillation. Potassium
channel blockade is revealed by increasing refractoriness and widening of the
Q-T
intervals of the ECG.
A third test involves exposing isolated rat hearts to increasing
concentrations of a compound. Ventricular pressures, heart rate, conduction
velocity
and ECG are recorded in the isolated heart in the presence of varying
concentrations of
the compound. The test provides evidence for direct toxic effects on the
myocardium.
Additionally, selectivity, potency and efficacy of action of a compound can be
ascertained under conditions simulating ischemia. Concentrations found to be
effective
in this test are expected to be efficacious in the electrophysiological
studies.
A fourth test is estimation of the antiarrhythmic activity of a compound
against the arrhythmias induced by coronary artery occlusion in anaesthetized
rats. It is
expected that a good antiarrhythmic compound will have antiarrhythmic activity
at
doses which have minimal effects on either the ECG, blood pressure or heart
rate under
normal conditions.
All of the foregoing tests are performed using rat tissue. In order to
ensure that a compound is not having effects which are only specific to rat
tissue,
further experiments are performed in dogs and primates. In order to assess
possible
sodium channel and potassium channel blocking action in vivo in dogs, a
compound is
tested for effects on the ECG, ventricular epicardial conduction velocity and
responses
to electrical stimulation. An anesthetized dog is subjected to an open chest
procedure to
expose the left ventricular epicardium. After the pericardium is removed from
the heart
a recording/stimulation electrode is sewn onto the epicardial surface of the
left ventricle.
Using this array, and suitable stimulation protocols, conduction velocity
across the
epicardium as well as responsiveness to electrical stimulation can be
assessed. This
information coupled with measurements of the ECG allows one to assess whether
sodium and/or potassium channel blockade occurs. As in the first test in rats,
a
CA 02268590 1999-04-12
compound is given as a series of increasing bolus doses. At the same time
possible
toxic effects of a compound on the dog's cardiovascular system is assessed.
The effects of a compound on the ECG and responses to electrical
stimulation are also assessed in intact, halothane anesthetized baboons (Papio
anubis).
5 In this preparation, a blood pressure cannula and ECG electrodes are
suitably placed in
an anesthetized baboon. In addition, a stimulating electrode is placed into
the right
ventricle, together with a monophasic action potential electrode. As in the
tests
described above, ECG and electrical stimulation response to a compound reveal
the
possible presence of sodium and/or potassium channel blockade. The monophasic
10 action potential also reveals whether a compound widens the action
potential, an action
expected of a potassium channel Mocker.
In addition to the tests described above and in Examples 28-31, the
pharmacological activity related to atrial arrhythmia (e.g. atrial
fibrillation and atrial
flutter) of the compounds of the present invention may be evaluated by other
in vivo
15 animal models established in the literature. Two such models are described
below in
Example 32 and Example 33.
As another example, in connection with the mitigation or prevention of
the sensation of pain, the following test may be performed. To determine the
effects of
a compound of the present invention on an animal's response to a sharp pain
sensation,
20 the effects of a slight prick from a 7.5 g weighted syringe fitted with a
23G needle as
applied to the shaved back of a guinea pig (Cavia porcellus) is assessed
following
subcutaneous administration of sufficient (50 ~1, 10 mg/ml) solution in saline
to raise a
visible bleb on the skin. Each test was done on the central area of the bleb
and also on
its periphery to check for diffusion of the test solution from the point of
administration.
25 If the test animal produces a flinch in response to the stimulus, this
demonstrates the
absence of blockade of pain sensation. Testing was carried out at intervals
for up to 4
hours post administration. The sites of bleb formation were examined after 24
hours
and showed no skin abnormalities consequent to local administration of test
substances
or of saline, the vehicle used for preparation of the test solutions.
CA 02268590 1999-04-12
56
Other Compositions
The present invention also provides kits that contain a pharmaceutical
composition which includes one or more compounds of the above formulae. The
kit
also includes instructions for the use of the pharmaceutical composition for
modulating
the activity of ion channels, for the treatment of arrhythmia or for the
production of
local analgesia and/or anesthesia, and for the other utilities disclosed
herein. Preferably,
a commercial package will contain one or more unit doses of the pharmaceutical
composition. For example, such a unit dose may be an amount sufficient for the
preparation of an intravenous injection. It will be evident to those of
ordinary skill in
the art that compounds which are light and/or air sensitive may require
special
packaging and/or formulation. For example, packaging may be used which is
opaque to
light, and/or sealed from contact with ambient air, and/or formulated with
suitable
coatings or excipients.
The following examples are offered by way of illustration and not by
way of limitation. In the Examples, and unless otherwise specified, starting
materials
were obtained from well-known commercial supply houses, e.g., Aldrich Chemical
Company (Milwaukee, WI), and were of standard grade and purity. "Ether" and
"ethyl
ether" each refers to diethyl ether; "h." refers to hours; "min." refers to
minutes; "GC"
refers to gas chromatography; "v/v" refers to volume per volume; and ratios
are weight
ratios unless otherwise indicated.
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57
EXAMPLES
EXAMPLE 1
(~)-TRANS-[2-(4-MORPHOLINYL)-1-(2-NAPHTHENETHOXY)] CYCLOHEXANE
S MONOHYDROCHLORIDE
(COMPOUND # 1 )
(i) Morpholine (5 mL, 57 mmol), cyclohexene oxide (5.8 mL, 57
mmol) and water (3 mL) were refluxed for l.Sh. GC analysis showed the reaction
to be
complete. The cooled mixture was partitioned between saturated NaOH solution
(50
mL) and ether (75 mL). The aqueous layer was backwashed with ether (30 mL) and
the
combined ether layers were dried over sodium sulfate. The ether was removed in
vacuo
to leave a yellow oil (9.83 g). The crude product, (~)-traps-[2-(4-
morpholinyl)]cyclohexanol, was purified by vacuum distillation (b.p. 75-
80°C at full
vacuum) to give a clear liquid (8.7 g). Yield 82.5%.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (6.0 g, 32.4 mmol) and triethylamine (6.8 mL, 48
mmol) in
dichloromethane (100 mL) was added via cannula a solution of methanesulfonyl
chloride (3.10 mL, 40 mmol) in dichloromethane (50 mL). The addition was
completed
in 10 min., the reaction mixture was stirred for another hour at 0°C
and then at room
temperature for 4 hours. The dichloromethane mixture was washed with water (2
x 50
mL) and the combined aqueous washings back extracted with dichloromethane (50
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide 8.5 g (100% yield) of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion previously washed with
hexanes (3 x 20 mL), (1.24 g, 51.6 mmol) in dry dimethylformamide (50 mL) was
added via cannula a solution of 2-naphthenethanol (6.8 g, 40 mmol) in dry
dimethylformamide (50 mL). Addition was followed by gas evolution and, as the
reaction mixture was stirred at room temperature, it began to gel. The
mesylate as
prepared in (ii) above was dissolved in dimethylformamide (50 mL) and the
resulting
solution was added quickly via cannula to the slurry of alcoholate. The
reaction
CA 02268590 1999-04-12
S8
mixture was heated to 80°C and then the temperature reduced to
40°C. The resulting
yellow solution was poured into ice-water (1500 mL) and extracted with ethyl
acetate (3
x 300 mL). The combined organic extracts were backwashed with a saturated
aqueous
solution of sodium chloride (500 mL) and dried over sodium sulfate.
Evaporation of
the solvent in vacuo provided 13.4 g of an amber oil which was dissolved in
water (150
mL) and the pH of the solution was adjusted to pH 2 with aqueous 1M HCI. The
acidic
aqueous solution was extracted with ethyl ether (2 x 100 mL) and then basified
to pH 10
with 50% sodium hydroxide aqueous solution. The basic aqueous solution was
extracted with ethyl ether (2 x 100 mL), the combined organic layers were
dried over
sodium sulfate and concentrated in vacuo to leave 7.16 g of the crude free
aminoether.
The crude product was purified by chromatography on silica gel 60 (70-230
mesh) with
a mixture of ethyl acetate-chloroform (1:1, v/v) as eluent to yield 4.37 g of
the pure free
base. The product was dissolved in ethyl ether (80 mL) and converted to the
monohydrochloride salt by adding saturated solution of HCl in ethyl ether (80
mL). An
oil came out of the solution, the solvent was evaporated in vacuo and the
residue
dissolved in the minimum amount of warm ethyl alcohol, addition of a large
volume of
ethyl ether triggered crystallization. The crystals were collected to afford
3.83 g (31
yield) of the title compound, m.p. 158-160°C, having the elemental
analysis indicated in
Table 1.
EXAMPLE 2
(~)-TRANS-[2-(4-MORPHOLINYL)-1-( 1-NAPHTHENETHOXY)] CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #2)
(i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (6.0 g, 32 mmol) and triethylamine (6.8 mL, 48 mmol)
in
dichloromethane (100 mL) was added via cannula a solution of methanesulfonyl
chloride (3.10 mL, 40 mmol) in dichloromethane (50 mL). The addition was
completed
CA 02268590 1999-04-12
59
in 10 min., the reaction mixture was stirred for another hour at 0°C
and then at room
temperature for 4 hours. The dichloromethane mixture was washed with water (2
x 50
mL) and the combined aqueous washings back extracted with dichloromethane (50
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide 9.0 g of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 20 mL) (1.30 g, S 1.6 mmol), in dry dimethylformamide (50 mL) was
added via cannula a solution of 1-naphthenethanol (6.8 g, 40 mmol) in dry
dimethylformamide (50 mL). Addition was followed by evolution of gas and the
reaction mixture was stirred at room temperature for 4 hours. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (3 min.) via cannula to the slurry of alcoholate.
The
reaction mixture was heated to 80°C for 3 hours, then the temperature
was reduced to
35°C for overnight stirring. The reaction mixture was poured into ice-
water (1500 mL)
and extracted with ethyl acetate (3 x 300 mL). The combined organic extracts
were
backwashed with a saturated aqueous solution of sodium chloride (500 mL) and
dried
over sodium sulfate. Evaporation of the solvent in vacuo provided 12.0 g of an
oil
which was dissolved in ether (80 mL) and treated with a saturated solution of
HCl in
ether. A sticky product came out of solution, the solvent was evaporated in
vacuo and
the resulting crude hydrochloride salt was dissolved in water (200 mL). The
acidic
aqueous solution was extracted with ethyl ether (2 x 100 mL) and then basified
to pH 10
with 50% sodium hydroxide aqueous solution. The basic aqueous solution was
extracted with ethyl ether (2 x 100 mL), the combined organic layers were
dried over
sodium sulfate and concentrated in vacuo to leave 7.20 g of the crude free
amino ether.
The crude product was purified by chromatography on silica gel 60 (70-230
mesh) with
a mixture of ethyl acetate-dichloromethane (1:1, v/v) as eluent to provide the
pure free
base. The product was dissolved in ethyl ether (80 mL) and converted to the
monohydrochloride salt by adding a saturated solution of HCl in ethyl ether
(80 mL). A
white product precipitated and this solid was collected and dissolved in the
minimum
amount of warm ethyl alcohol; addition of a large volume of ethyl ether
triggered
CA 02268590 1999-04-12
crystallization. The crystals were collected to afford 2.30 g of the title
compound, m.p.
198-200°C, having the elemental analysis indicated in Table 1.
EXAMPLE 3
S (~)-TRANS-[2-(4-MORPHOLINYL)-1-(4-BROMOPHENETHOXY)]CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #3)
(i) The starting trans-aminocyclohexanol is prepared according to
example 1.
10 (ii) To a chilled (0°C) solution of
(~)-trans-[2-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine
(3.4 mL,
24 mmol) in dichloromethane (2S mL) was added via cannula a solution of
methanesulfonyl chloride (1.SS mL, 20.0 mmol) in dichloromethane (2S mL). The
addition was completed in S min., the reaction mixture was stirred for another
hour at
1 S 0°C and then at room temperature for 2 hours. The reaction mixture
was diluted with
dichloromethane (SO mL) and washed with water (2 x SO mL) and the combined
aqueous washings back extracted with dichloromethane (2S mL). The combined
organic layers were dried over sodium sulfate and concentrated in vacuo to
provide 4.7
g of the crude mesylate.
20 (iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.62 g, 25.8 mmol) in dry dimethylformamide (2S mL) was
added via cannula a solution of 4-bromophenethylalcohol (4.0 g, 20 mmol) in
dimethylformamide (SO mL). Addition was followed by evolution of gas and the
reaction mixture was stirred at room temperature for 4 hours. The mesylate as
prepared
2S in (ii) above was dissolved in dry dimethylformamide (SO mL) and the
resulting
solution was added quickly (3 min.) via cannula to the slurry of alcoholate.
The
reaction mixture was heated to 80°C for 2 hours, then the temperature
was reduced to
3S°C and the reaction stirred overnight. The reaction mixture was
poured into ice-water
(800 mL) and extracted with ethyl acetate (3 x 200 mL). The combined organic
extracts
30 were backwashed with a saturated aqueous solution of sodium chloride (1S0
mL) and
CA 02268590 1999-04-12
61
dried over sodium sulfate. Evaporation of the solvent in vacuo provided 7.4 g
of an oil
which was dissolved in ether (80 mL) was treated with a saturated solution of
HCl in
ether. An oil came out of solution, the solvent was evaporated in vacuo and
the residue
was dissolved in water (100 mL). The acidic aqueous solution was extracted
with ethyl
ether (2 x 50 mL) and then basified to pH 10 with 50% sodium hydroxide aqueous
solution. The basic aqueous solution was extracted with ethyl ether (2 x 50
mL), the
combined organic layers were dried over sodium sulfate and concentrated in
vacuo to
leave 3.67 g of the crude free amino ether. The crude product was purified by
chromatography on silica gel 60 (70-230 mesh) with a mixture of ethyl
acetate-dichloromethane (1:1, v/v) as eluent to provide the pure free base.
The product
was dissolved in ethyl ether (30 mL) and converted to the monohydrochloride
salt by
adding a saturated solution of HCl in ethyl ether (30 mL). The solvent was
evaporated
and the residue dissolved in the minimum amount of ethyl alcohol, addition of
a large
volume of ethyl ether triggered crystallization. The crystals were collected
to afford
1.31 g of the title compound, m.p. 148-151°C, having the elemental
analysis indicated
in Table 1.
EXAMPLE 4
(~)-TRANS-[2-(4-MORPHOLINYL)-1-[2-(2-NAPHTHOXY)ETHOXY)] CYCLOHEXANE
2O MONOHYDROCHLORIDE
(COMPOUND #4)
(i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24
mmol) in
dichloromethane (50 mL) was added via cannula a solution of methanesulfonyl
chloride
(1.55 mL, 20.0 mmol) in dichloromethane (50 mL). The addition was completed in
10
min., the reaction mixture was stirred for another hour at 0°C and then
at room
temperature for 4 hours. The dichloromethane mixture was washed with water (2
x 50
mL) and the combined aqueous washings back extracted with dichloromethane (50
CA 02268590 1999-04-12
62
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide 4.3 g (100% yield) of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.7 g, 29 mmol) in dry dimethylformamide (50 mL) was
added
via cannula a solution of 2-(2-naphthoxy)ethanol (3.76 g, 20.0 mmol) in dry
dimethylformamide (50 mL). Addition was followed by evolution of gas and the
reaction mixture was stirred at room temperature for 90 min. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (3 min.) via cannula to the reaction mixture. The
resulting
reaction mixture was heated overnight to 90°C and then cooled to room
temperature.
The reaction mixture was poured into ice-water (800 mL) and extracted with
ethyl
acetate (3 x 200 mL). The combined organic extracts were backwashed with a
saturated
aqueous solution of sodium chloride (300 mL) and dried over sodium sulfate.
Evaporation of the solvent in vacuo provided 7.8 g of a yellow oil which was
dissolved
in ether (100 mL) and treated with a saturated solution of HCl in ether (100
mL). The
resulting precipitate was collected, partially solubilized in water (200 mL)
and the
heterogeneous aqueous solution was extracted with ether (2 x 100 mL). The
remaining
insoluble material was collected and recrystallized in boiling ethanol (75 mL)
to provide
a first crop of the desired product. The acidic aqueous solution was basified
to pH 10
with aqueous 50% NaOH and extracted with ether (2 x 50 mL). The combined
organic
extracts were dried over sodium sulfate and concentrated in vacuo to provide
1.6 g of
the crude free amino ether. The product was purified by chromatography on
silica gel
60 (70-230 mesh) using a mixture of ethyl acetate-dichloromethane as eluent to
yield
0.73 g of a pale yellow oil. The pure free base was then dissolved in ether
(50 mL) and
converted to the monohydrochloride salt by adding a saturated solution of HC1
in ether
(50 mL). The white precipitate was collected and recrystallized in boiling
ethanol (40
mL) to provide a second crop. Combination of the two crops afforded 1.03 g of
the title
compound, m.p. 235-237°C, having the elemental analysis indicated in
Table 1.
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63
EXAMPLE S
(~)-TRANS-[2-(4-MORPHOLINYL)-1-[2-(4-BROMOPHENOXY)ETHOXY)]]CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #S)
S (i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24
mmol) in
dichloromethane (SO mL) was added via cannula a solution of methanesulfonyl
chloride
(1.SS mL, 20.0 mmol) in dichloromethane (SO mL). The addition was completed in
10
min., the reaction mixture was stirred for another hour at 0°C and then
at room
temperature for 4 hours. The dichloromethane mixture was washed with water (2
x SO
mL) and the combined aqueous washings back extracted with dichloromethane (SO
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
1 S vacuo to provide 3.95 g (92% yield) of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.63 g, 26 mmol) in dry dimethylformamide (SO mL) was
added
via cannula a solution of 2-(4-bromophenoxy)ethanol (4.34 g, 20.0 mmol) in dry
dimethylformamide (SO mL). Addition was followed by evolution of a gas and the
reaction mixture was stirred at room temperature for 90 min. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (SO mL) and the resulting
solution was added quickly (3 min.) via cannula to the reaction mixture. The
reaction
mixture was heated to 90°C for 90 min. and then the temperature was
reduced to 40°C
and the reaction was stirred overnight. The reaction mixture was poured into
ice-water
2S (800 mL) and extracted with ethyl acetate (3 x 200 mL). The combined
organic extracts
were backwashed with a saturated aqueous solution (300 mL) of sodium chloride
and
dried over sodium sulfate. Evaporation of the solvent in vacuo provided 8.35 g
of a
yellow oil which was dissolved in ether (100 mL) and treated with a saturated
solution
of HCl in ether (100 mL). The resulting white solid was collected and
recrystallized in
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boiling ethanol (1S0 mL) to yield 3.7 g (S4% yield) of the pure title
compound, m.p.
228-230°C, having the elemental analysis indicated in Table 1.
EXAMPLE 6
S (~)-TRANS-[2-(4-MORPHOLINYL)-1-(3,4-DIMETHOXYPHENETHOXY)]CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #6)
(i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24
mmol) in
dichloromethane (SO mL) was added via cannula a solution of methanesulfonyl
chloride
(1.SS mL, 20.0 mmol) in dichloromethane (SO mL). The addition was completed in
10
min., the reaction mixture was stirred for another hour at 0°C and then
at room
1 S temperature for 4 hours. The dichloromethane mixture was washed with water
(2 x SO
mL) and the combined aqueous washings back extracted with dichloromethane (SO
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide 4.18 g of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.64 g, 27 mmol) in dry dimethylformamide (SO mL) was
added
via cannula a solution of 3,4-dimethoxyphenethyl alcohol (3.64 g, 20.0 mmol)
in dry
dimethylformamide (SO mL). Addition was followed by evolution of a gas and the
reaction mixture was stirred at room temperature for 90 min. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (SO mL) and the resulting
2S solution was added quickly (3 min.) via cannula to the reaction mixture.
The reaction
mixture was heated to 80°C for 90 min. and then the temperature was
reduced to 40°C
and stirring continued overnight. The reaction mixture was poured into ice-
water (800
mL) and extracted with ethyl acetate (3 x 200 mL). The combined organic
extracts
were backwashed with a saturated aqueous solution of sodium chloride (300 mL)
and
dried over sodium sulfate. Evaporation of the solvent in vacuo provided 7.18 g
of the
CA 02268590 1999-04-12
crude product which was dissolved in ether (100 mL) and treated with a
saturated
solution of HCl in ether (100 mL). The solvent was evaporated in vacuo and the
residual oil was taken up with water (100 mL) and extracted with ether (2x50
mL). The
aqueous layer was basified to pHlO with 50% NaOH aqueous solution and
extracted
5 with ether (2x50 mL). The combined organic layers were dried over sodium
sulfate and
concentrated in vacuo. The crude product was purified by chromatography on
silica gel
60 (70-230 mesh) using a mixture of ethyl acetate and dichloromethane (1:1,
v/v) as
eluent to provide 2.8 g of a pale yellow oil. The free base was dissolved in
ether (80
mL) and converted to the monohydrochloride salt by adding a saturated solution
of HCl
10 in ether (80 mL). The sticky precipitate was collected, dissolved in the
minimum
amount of ethanol and a large excess of ether was added to trigger
crystallization of
2.24 g (36% yield) of the title compound, m.p. 148-150°C, having the
elemental
analysis indicated in Table 1.
15 EXAMPLE 7
(~)-TRANS-[2-( 1-PYRROLIDINYL)-1-( 1-NAPHTHENETHOXY)] CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #7)
(i) Pyrrolidine (25 mL, 300 mmol), cyclohexene oxide (30 mL, 297
20 mmol) and water (10 mL) were refluxed for 3 h. GC analysis showed the
reaction to be
complete. The cooled mixture was partitioned between saturated NaOH solution
(10
mL) and ether (150 mL). The aqueous layer was backwashed with ether (2x100 mL)
and the combined ether layers were dried over sodium sulfate. The ether was
removed
in vacuo to leave a yellow oil. The crude product was purified by vacuum
distillation
25 (b.p. 66-69°C at full vacuum) to give a clear liquid (43.9 g). Yield
87%.
(ii) To a chilled (0°C) solution of
(~)-traps-[2-(pyrrolidinyl)]cyclohexanol (2.74 g, 16.2 mmol) and triethylamine
(3.4
mL, 24 mmol) in dichloromethane (50 mL) was added via cannula a solution of
methanesulfonyl chloride (1.55 mL, 20.0 mmol) in dichloromethane (50 mL). The
30 addition was completed in 10 min., the reaction mixture was washed with
water (2 x 50
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66
mL) and the combined aqueous washings back extracted with dichloromethane (50
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide 3.24 g of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 ml), (0.64 g, 27 mmol) in dry dimethylformamide (50 mL) was
added
via cannula a solution of 1-naphthenethanol (3.64 g, 20.0 mmol) in dry
dimethylformamide (50 mL). Addition was followed by evolution of a gas and the
reaction mixture was stirred at room temperature for 90 min. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (3 min.) via cannula to the reaction mixture. The
reaction
mixture was heated to 80°C for 90 min. and then its temperature was
reduced to 40°C
and it was stirred overnight. The reaction mixture was poured into ice-water
(800 mL)
and extracted with ethyl acetate (3 x 200 mL). The combined organic extracts
were
backwashed with a saturated aqueous solution with sodium chloride (300 mL) and
dried
over sodium sulfate. Evaporation of the solvent in vacuo provided 9.00 g of
the crude
product which was dissolved in ether (50 mL) and treated with a saturated
solution of
HCl in ether (50 mL). The solvent was evaporated in vacuo and the residual oil
was
taken up with water (100 mL) and extracted with ether (2x50 mL). The aqueous
layer
was basified to pHlO with 50% NaOH aqueous solution and extracted with ether
(2x50
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo. The crude product was purified by chromatography on silica gel 60 (70-
230
mesh) using a mixture of ethyl methanol and chloroform (2:8, v/v) as eluent.
The free
amino ether was partially dissolved in ether (80 mL), insoluble materials were
filtered
off, and then a saturated solution of HCl in ether (80 mL) was added to the
filtrate. The
solvent was evaporated in vacuo, the residue was dissolved in acetone and
addition of
aliquots of ether triggered slow crystallization. 2 crops of the title
compound (0.88 g),
m.p. 103-105°C were collected, having the elemental analysis indicated
in Table 1.
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EXAMPLE 8
(~)-TRANS-[2-(4
MORPHOLINYL)-1-(2-(BENZO [B] THIOPHEN-3-YL)ETHOXY)] CYCLOHEXANE
MONOHYDROCHLORIDE
S (COMPOUND #8)
(i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24
mmol) in
dichloromethane (50 mL) was added via cannula a solution of methanesulfonyl
chloride
(1.55 mL, 20.0 mmol) in dichloromethane (50 mL). The addition was completed in
5
min., the reaction mixture was stirred for another hour at 0°C and then
at room
temperature for 3 hours. The reaction mixture was washed with water (3 x 30
mL) and
the combined aqueous washings back extracted with dichloromethane (50 mL). The
combined organic layers were dried over sodium sulfate and concentrated in
vacuo to
provide 5.25 g of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.60 g, 25 mmol) in dry dimethylformamide (50 mL) was
added
via cannula a solution of 2-(benzo[b]thiophen-3y1)ethanol (3.56 g, 20.0 mmol)
in dry
dimethylformamide (50 mL). Addition was followed by evolution of gas and the
reaction mixture was stirred at room temperature for 3 hours. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (2 min.) via cannula to the reaction mixture. The
reaction
mixture was heated to 75°C for 2 hours, then the temperature was
reduced to 65°C and
stirring continued overnight. The reaction mixture was poured into ice-water
(800 mL)
and extracted with ethyl acetate (3 x 200 mL). The combined organic extracts
were
backwashed with a saturated aqueous solution (300 mL) of sodium chloride and
dried
over sodium sulfate. Evaporation of the solvent in vacuo provided 7.7 g of an
oil which
was dissolved in ether (100 mL) and treated with a saturated solution of HCl
in ether
(100 mL). An oil precipitated from the solution, the solvent was evaporated in
vacuo
CA 02268590 1999-04-12
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and the resulting crude hydrochloride salt was dissolved in water (200 ml).
The acidic
aqueous solution was extracted with ethyl ether (2 x 100 mL) and then basified
to pH 10
with aqueous 50% sodium hydroxide. The basic aqueous solution was extracted
with
ethyl ether (3 x 100 mL), the combined organic layers were dried over sodium
sulfate
and concentrated in vacuo to leave 3.30 g of the crude free aminoether. The
crude
product was purified by chromatography on silica gel 60 (70-230 mesh) with a
mixture
of ethyl acetate and dichloromethane (l:l, v/v) as eluent to provide the free
base. The
product was dissolved in ethyl ether (100 mL) and converted to the
monohydrochloride
salt by adding a saturated solution of HCl in ethyl ether ( 100 mL). The
solvent was
evaporated in vacuo and the residue was dissolved in the minimum amount of
boiling
methanol to provide a first crop (0.7 g) of crystalline product on cooling.
Addition of
diethyl ether to the methanol filtrate provided a second crop (0.55 g). The
two crops
were combined to yield 1.25 g of the title compound, m.p. 158-160°C,
having the
elemental analysis indicated in Table 1.
EXAMPLE 9
(~)-TRANS-[2-(4-MORPHOLINYL)-1-(2-(BENZO [B] THIOPHEN-4-YL)ETHOXY)]
CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND #9)
(i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24.0
mmol)
in dichloromethane (50 mL) was added via cannula a solution of methanesulfonyl
chloride (1.55 mL, 20,0 mmol) in dichloromethane (50 mL). The addition was
completed in 5 min., the reaction mixture was stirred for another hour at
0°C and then at
room temperature for 3 hours. The reaction mixture was washed with water (2 x
30
mL) and the combined aqueous washings back extracted with dichloromethane (50
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide 4.24 g of the crude mesylate.
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(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.60 g, 25 mmol) in dry dimethylformamide (50 mL) was
added
via cannula a solution of 2-(benzo[b]thiophen-4-yl)ethanol (3.56 g, 20.0 mmol)
in dry
dimethylformamide (50 mL). Addition was followed by evolution of a gas and the
reaction mixture was stirred at room temperature for 3 hours. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (2 min.) via cannula to the reaction mixture. The
reaction
mixture was heated to 85°C for 2 hours, then the temperature was
reduced to 40°C and
the reaction stirred overnight. The reaction mixture was poured into ice-water
(800 mL)
and extracted with ethyl acetate (3 x 200 mL). The combined organic extracts
were
backwashed with a saturated aqueous solution (300 mL) of sodium chloride and
dried
over sodium sulfate. Evaporation of the solvent in vacuo provided 8.2 g of an
oil which
was dissolved in ether (100 mL) and treated with a saturated solution of HCl
in ether
(100 mL). An oil precipitated and the solvent was evaporated in vacuo and the
resulting
crude hydrochloride salt was dissolved in water (200 mL). The acidic aqueous
solution
was extracted with ethyl ether (2 x 100 mL) and then basified to pH 10 with an
aqueous
solution of sodium hydroxide (50°~o w/v). The basic aqueous solution
was extracted
with ethyl ether (3 x 100 mL), the combined organic layers were dried over
sodium
sulfate and concentrated in vacuo to leave 3.0 g of the crude free aminoether.
The crude
product was purified by chromatography on silica gel 60 (70-230 mesh) with a
mixture
of ethyl acetate-dichloromethane (1:1, v/v) as eluent to provide the pure free
base. The
product was dissolved in ethyl ether (50 mL) and converted to the
monohydrochloride
salt by adding a saturated solution of HCl in ethyl ether (50 mL). The solvent
was
evaporated in vacuo, the residue was dissolved in the minimum amount of cold
ethanol
and addition of ether triggered formation of crystals (1.17 g), m.p. 178-
180°C, having
the elemental analysis indicated in Table 1.
CA 02268590 1999-04-12
EXAMPLE 10
(~)-TRANS-[2-(4-MORPHOLINYL)-1-(3-BROMOPHENETHOXY)] CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #lO)
5 (i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24
mmol) in
dichloromethane (50 mL) was added via cannula a solution of methanesulfonyl
chloride
10 (1.55 mL, 20.0 mmol) in dichloromethane (50 mL). The addition was completed
in 5
min., the reaction mixture was stirred for another hour at 0°C and then
at room
temperature for 3 hours. The reaction mixture was washed with water (2 x 30
mL) and
the combined aqueous washings back extracted with dichloromethane (50 mL). The
combined organic layers were dried over sodium sulfate and concentrated in
vacuo to
15 provide 5.4 g of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.60 g, 25 mmol) in dry dimethylformamide (50 mL) was
added
via cannula a solution of 3-bromophenethyl alcohol (4.0 g, 20 mmol) in dry
dimethylformamide (50 mL). Addition was followed by evolution of a gas and the
20 reaction mixture was stirred at room temperature for 3 hours. The mesylate
as prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (2 min.) via cannula to the reaction mixture. The
reaction
mixture was heated to 85°C for 2 hours, then the temperature was
reduced to 45°C and
the reaction stirred overnight. The reaction mixture was poured into ice-water
(800 mL)
25 and extracted with ethyl acetate (3 x 200 mL). The combined organic
extracts were
backwashed with a saturated aqueous solution of sodium chloride (300 mL) and
dried
over sodium sulfate. Evaporation of the solvent in vacuo provided 8.0 g of an
oil which
was dissolved in ether (100 mL) and treated with a saturated solution of HCl
in ether
(100 mL). An oil precipitated and the solvent was evaporated in vacuo and the
resulting
30 crude hydrochloride salt was dissolved in water (200 mL). The acidic
aqueous solution
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was extracted with ethyl ether (2 x 100 mL) and then basified to pH 10 with an
aqueous
solution of sodium hydroxide (SO% w/v). The basic aqueous solution was
extracted
with ethyl ether (3 x 100 mL), the combined organic layers were dried over
sodium
sulfate and concentrated in vacuo to leave 2.9 g of the crude free aminoether.
The crude
S product was purified by chromatography on silica gel 60 (70-230 mesh) with a
mixture
of ethyl acetate-dichloromethane (1:1, v/v) as eluent to provide the pure free
base. The
product was dissolved in ethyl ether (SO mL) and converted to the
monohydrochloride
salt by adding saturated solution of HCl in ethyl ether (SO mL). The solvent
was
evaporated in vacuo, the residue was dissolved in the minimum amount of cold
ethanol
and addition of ether triggered formation of crystals (O.S3 g), m.p. 14S-
148°C, having
the elemental analysis indicated in Table 1.
EXAMPLE 11
1 S (~)-TRANS-[2-(4-MORPHOLINYL)-1-(2-BROMOPHENETHOXY)]CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND # 11 )
(i) The starting trans-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-trans-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24.0
mmol)
in dichloromethane (SO mL) was added via cannula a solution of methanesulfonyl
chloride (1.SS mL, 20.0 mmol) in dichloromethane (SO mL). The addition was
completed in S min., the reaction mixture was stirred for another hour at
0°C and then at
2S room temperature for 3 hours. The reaction mixture was washed with water (2
x 30
mL) and the combined aqueous washings back extracted with dichloromethane (SO
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide S.9 g of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.60 g, 2S mmol) in dry dimethylformamide (SO mL) was
added
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via cannula a solution of 2-bromophenethyl alcohol (4.0 g, 20 mmol) in dry
dimethylformamide (50 mL). Addition was followed by evolution of a gas and the
reaction mixture was stirred at room temperature for 3 hours. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (2 min.) via cannula to the reaction mixture. The
reaction
mixture was heated to 85°C for 2 hours, then the temperature was
reduced to 45°C and
the reaction stirred overnight. The reaction mixture was poured into ice-water
(800 mL)
and extracted with ethyl acetate (3 x 200 mL). The combined organic extracts
were
backwashed with a saturated aqueous solution of sodium chloride (300 mL) and
dried
over sodium sulfate. Evaporation of the solvent in vacuo provided 8.4 g of an
oil which
was dissolved in 1.0 M HCl aqueous solution (50 mL), the volume was adjusted
to 200
mL with water and the pH adjusted to pH 2 with 1.0 M HCl aqueous solution. The
acidic aqueous solution was extracted with ethyl ether (3 x 100 mL) and then
basified to
pH 10 with 50% aqueous sodium hydroxide solution. The basic aqueous solution
was
extracted with ethyl ether (3 x 100 mL), the combined organic layers were
dried over
sodium sulfate and concentrated in vacuo to leave 2.8 g of the crude free
aminoether.
The crude product was purified by chromatography on silica gel 60 (70-230
mesh) with
a mixture of ethyl acetate-dichloromethane (1:1, v/v) as eluent to provide the
pure free
base. The product was dissolved in ethyl ether (50 mL) and converted to the
monohydrochloride salt by adding saturated solution of HCl in ethyl ether (50
mL).
The solvent was evaporated in vacuo, the residue was dissolved in the minimum
amount of cold ethanol and addition of ether triggered formation of crystals
which were
collected in two crops (0.74 g), m.p. 140-142°C, having the elemental
analysis indicated
in Table 1.
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EXAMPLE 12
(~)-TRAMS-[2-(4-
MORPHOLINYL)-1-(3-(3 ,4-DIMETHOXYPHENYL)-1-PROPOXY)] CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND # 12)
(i) The starting traps-aminocyclohexanol is prepared according to
example 1.
(ii) To a chilled (0°C) solution of (~)-traps-[2-(4-
morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) and triethylamine (3.4 mL, 24
mmol) in
dichloromethane (50 mL) was added via cannula a solution of methanesulfonyl
chloride
(1.55 mL, 20.0 mmol) in dichloromethane (50 mL). The addition was completed in
10
min., the reaction mixture was stirred for another hour at 0°C and then
at room
temperature for 4 hours. The dichloromethane mixture was washed with water (2
x 50
mL) and the combined aqueous washings back extracted with dichloromethane (50
mL). The combined organic layers were dried over sodium sulfate and
concentrated in
vacuo to provide the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.6 g, 27 mmol) in dry dimethylformamide (50 mL) was
added
via cannula a solution of 3-(3,4-dimethoxyphenyl)-1-propanol (3.93 g, 20.0
mmol) in
dry dimethylformamide (50 mL). Addition was followed by evolution of a gas and
the
reaction mixture was stirred at room temperature for 90 min. The mesylate as
prepared
in (ii) above was dissolved in dry dimethylformamide (50 mL) and the resulting
solution was added quickly (3 min.) via cannula to the reaction mixture. The
reaction
mixture was heated to 90°C for 90 min. and then the temperature was
reduced to 45°C
and stirring continued overnight. The reaction mixture was poured into ice-
water (800
mL) and extracted with ethyl acetate (3 x 200 mL). The combined organic
extracts
were backwashed with a saturated aqueous solution of sodium chloride (300 mL)
and
dried over sodium sulfate. Evaporation of the solvent in vacuo provided 8.5 g
of the
crude product which was dissolved in 15% HCl aqueous solution (200 mL) and
extracted with ether (2x100 mL). The aqueous layer was basified to pHlO with
50%
CA 02268590 1999-04-12
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NaOH aqueous solution and extracted with ether (2x100 mL). The combined
organic
layers were dried over sodium sulfate and concentrated in vacuo. The crude
product
was purified by chromatography on silica gel 60 (70-230 mesh) using a mixture
of ethyl
acetate and dichloromethane (1:1, v/v) as eluent to provide the free base
which was
dissolved in ether (80 mL) and converted to the monohydrochloride salt by
adding a
saturated solution of HCl in ether (80 mL). The sticky precipitate was
collected,
dissolved in the minimum amount of warm ethanol and a large excess of ether
was
added to trigger crystallization of the title compound, m.p. 175-177°C,
having the
elemental analysis indicated in Table 1.
EXAMPLE 13
(~)-TRANS-[2-[BIS(2 METHOXYETHYL)AMINO]-1-(2-NAPHTHENETHOXY)]CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #13)
(i) Bis-(2-methoxyethyl)amine(25 mL, 169 mmol) and cyclohexene
oxide (17.2 mL, 170 mmol) were mixed in water (5 mL) and the resulting mixture
was
refluxed for 30 hours. The cooled reaction mixture was partitioned between 10%
NaOH aqueous (200 mL) and diethyl ether (200 mL). The aqueous layer was
extracted
twice more with diethyl ether (2 x 100 mL), the combined organic layers were
washed
with water (8 mL) and dried over sodium sulfate. The solvent was evaporated in
vacuo
to provide the crude product which was vacuum distilled to provide 26.4 g of
pure
colorless oil.
(ii) To a chilled (0°C) solution of (t)-traps-2-[bis(2-
methoxyethyl)amino]cyclohexanol) 4.63 g, 20.00 mmol) and triethylamine (3.4
mL,
24.00 mmol) in dichloromethane (50 mL) was added via cannula a solution of
methanesulfonyl chloride (1.55 mL, 20.00 mmol) in dichloromethane (50 mL). The
additional was completed in 5 min., the reaction mixture was stirred for
another hour at
0°C and then at room temperature for 4 hours. The reaction mixture was
washed with
water (2 x 30 mL) and the combined aqueous washings backextracted with
CA 02268590 1999-04-12
dichloromethane (50 mL). The combined organic layers were dried over sodium
sulfate
and concentrated in vacuo to provide 4.87 g of the crude mesylate.
(iii) To sodium hydride, 80% oil dispersion, previously washed with
hexanes (3 x 10 mL), (0.60 g, 25.00 mmol) in anhydrous dimethylformamide (50
mL)
5 was added via cannula a solution of 2-naphthenethanol (3.4 g, 20.00 mmol) in
anhydrous dimethylformamide (50 mL). Addition was followed by hydrogen
bubbling,
the reaction mixture was stirred at room temperature for 90 min. The mesylate
as
prepared in (ii) above was dissolved in dry dimethylformamide (50 mL) and the
resulting solution was added quickly (3 min.) via cannula to the reaction
mixture. The
10 reaction mixture was heated up to 90°C in 2 hours, then the
temperature was reduced to
40°C and the reaction stirred overnight. The reaction mixture was
poured into ice-water
(800 mL) and extracted with ethyl acetate (3 x 200 mL). The combined organic
extracts
were backwashed with a sodium chloride saturated aqueous solution (300 mL) and
dried over sodium sulfate. Evaporation of the solvent in vacuo provided 8.1 g
of an oil
15 which was dissolved in 1M HCl aqueous solution (50 mL) and the volume
completed to
200 mL with water. The acidic aqueous solution was extracted with diethyl
ether (2 x
100 mL) and then basified to pH 10 with 50% sodium hydroxide aqueous solution.
The
basic aqueous solution was extracted with ethyl ether (2 x 100 mL), the
combined
organic layers were dried over sodium sulfate and concentrated in vacuo to
leave 3.58 g
20 of the crude free aminoether. The crude product was purified by
chromatography
column using silica gel 60, 70-230 mesh from BDH Inc. with a mixture of
methanol and
dichloromethane (2:8, v/v) as eluent to provide the pure free base. The
product was
dissolved in diethyl ether (50 mL) and converted to the monohydrochloride salt
by
adding etheral HCl (50 mL). The solvent was evaporated in vacuo to yield 0.75
g of the
25 title compound (not recrystallized).
CA 02268590 1999-04-12
76
EXAMPLE 14
( 1 R,2R)/( 1 S,2S)-2-(4-MoRPHOLINYL)-1-(3,4-DICHLOROPHENETHOXY)
CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND #14)
The basic overall approach used to synthesize this compound is
analogous to that shown in Figure 1.
(i) (1R,2R)/(1S,2S)-2-(4-Morpholinyl)cyclohexanol: A mixture of
cyclohexene oxide (206.5 mL, 2 mol, 98%) and morpholine (175 mL, 2 mol) in
water
(60 mL) was refluxed for 3.5 h. Morpholine (5.3 mL) was added to the reaction
mixture, which was then further refluxed for 1.5 h. in order to complete the
reaction.
The cooled reaction mixture was then partitioned between 40% NaOH aqueous
solution
( 100 mL) and diethyl ether (200 mL). The aqueous layer was separated from the
organic layer and extracted twice more with diethyl ether (2 x 100 mL). The
combined
organic extracts were dried over sodium sulfate and the solvent was evaporated
in
vacuo. Vacuum distillation yielded 342.3 g (92.4%) of the title compound.
(ii) To a chilled (0°C) solution of (1R,2R)/(1S,2S)-2-(4
morpholinyl)cyclohexanol (40.76 g, 0.22 mol) and triethylamine (36.60 mL, 0.26
mol)
in dichloromethane (400 mL) was added dropwise a solution of methanesulfonyl
chloride (20.53 mL, 0.26 mol) in dichloromethane (50 mL). The reaction mixture
was
stirred at 0°C for 45 min. and then at room temperature for 3 hours.
The reaction
mixture was then washed with water (2 x 100 mL); the combined washings were
back-
extracted with dichloromethane (100 mL). The combined organic extracts were
dried
over sodium sulfate and the solvent was evaporated in vacuo to yield the crude
mesylate
suitable for the next step without any further purification.
(iii) 3,4-Dichlorophenethyl alcohol: To a solution of lithium
aluminum hydride (7.79 g, 195 mmol) in anhydrous diethyl ether (435 mL) was
added
slowly as a powder, via a solid dropping funnel, 3,4-dichlorophenyl acetic
acid (27.20
g, 130 mmol). When the addition was completed, the reaction mixture was
refluxed for
12 hours. The reaction was quenched by cautious addition of saturated sodium
sulfate
CA 02268590 1999-04-12
77
aqueous solution (20 mL), the resulting insoluble was then filtered off and
the filtrate
was concentrated in vacuo to yield 25.09 g of the desired alcohol.
(iv) To NaH (6.00 g, 0.2 mol, 80% dispersion in oil) in anhydrous
ethylene glycol dimethyl ether (200 mL) was added a solution of 3,4-
dichlorophenethyl
alcohol (38.87 g, 0.2 mol) in anhydrous ethylene glycol dimethyl ether (100
mL). The
resulting mixture was stirred for 3 hours at ambient temperature under argon
atmosphere.
(v) The mesylate (ii) in anhydrous ethylene glycol dimethyl ether
( 100 mL) was added quickly to the alkoxide (iv) and the resulting reaction
mixture was
readily refluxed for 16 hours. To the cooled reaction mixture was added water
(200
mL) and the organic solvent was evaporated in vacuo. The resulting aqueous
solution
was further diluted with water (200 mL) and the pH was adjusted to pH 1.5 with
10%
HCl aqueous solution. The acidic aqueous layer was extracted with diethyl
ether (500
mL) to eliminate the unreacted 3,4-dichlorophenethyl alcohol. Further
basification of
the aqueous layer with SM NaOH aqueous solution to pH 5.7 followed by
extraction
with diethyl ether provided the crude title compound contaminated with some
remaining mesylate (ii). The solvent of the organic extract at pH 5.7 was
evaporated in
vacuo, the residue was then refluxed in a mixture of ethanol-water (1:1, v/v,
200 mL) in
the presence of sodium hydride (4.12 g, 0.1 mol) for 2 hours in order to
hydrolyzed the
remaining mesylate. The cooled reaction mixture was diluted with water (300
mL) and
the organic solvent was evaporated in vacuo. The pH of the residual aqueous
solution
was adjusted to pH 5.7 with 6M HCl aqueous solution followed by extraction
with
diethyl ether (700 mL). The organic extract was concentrated in vacuo to yield
the pure
aminoether. The residual product was then partitioned between 1 M HCl aqueous
solution (300 mL) and dichloromethane (300 mL). The acidic aqueous solution
was
extracted twice more with dichloromethane (2 x 300 mL). The combined organic
layers
were dried over sodium sulfate, the solvent was evaporated in vacuo and the
residue
was recrystallized from a mixture of ethanol-hexanes (3:7, v/v, 700 mL) to
yield 49.3 g
of the title compound, having the elemental analysis indicated in Table 1.
CA 02268590 1999-04-12
78
EXAMPLE 15
( 1 R,2R)/( 1 S,2 S)-2-(3-KETOPYRROLIDINYL)-1-( 1-NAPHTHENETHOXY)CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #15)
Synthesis of Compound #15 follows the sequence of reactions shown in
Figure 4A and Figure 4B, and is described in detail below.
(i) N-Benzyloxycarbonvl-3-3-pyrrolidinol: To a chilled (-60°C)
solution of (R)-(+)-3-pyrrolidinol (20.0 g, 98%, 224.9 mmol) and triethylamine
(79.2
mL, 99%, 562 mmol) in dichloromethane (200 mL) was added dropwise a solution
of
benzyl chloroformate (33.8 mL, 95%, 224.9 mmol) in dichloromethane (80 mL).
After
the addition was completed within 45 min, the reaction mixture (a yellow
suspension)
was allowed to warm up to room temperature and was stirred under argon at room
temperature overnight. The reaction mixture was then quenched with 1 M HCl
aqueous
solution (350 mL) and the organic layer was collected. The acidic aqueous
layer was
extracted with dichloromethane (2 x 150 mL) and the combined organic layers
were
dried over sodium sulfate. Evaporation in vacuo of the solvent provided 59.62
g of pale
yellow oil, which was further pumped under high vacuum for 15 min to yield
58.23 g
(17% over theoretical yield) of the crude title compound suitable for the next
step
without any further purification.
(ii) N-Benzylox;rcarbonyl-3 pyrrolidinone: To a chilled (-60°C)
solution of oxalyl chloride (23 mL, 98%, 258.6 mmol) in dichloromethane (400
mL)
was added dropwise a solution of anhydrous dimethyl sulfoxide (36.7 mL, 517.3
mmol)
in dichloromethane (20 mL) at such a rate to keep the temperature below -
40°C. The
reaction mixture was then stirred at -60°C for 15 min. Then a solution
of N-
benzyloxycarbonyl-3-pyrrolidinol (58.22 g, step i, no more than 224.9 mmol) in
dichloromethane (80 mL) was added dropwise, keeping the reaction mixture
temperature below -50°C. The reaction mixture was then stirred at -
60°C for 30 min
before adding triethylamine (158.3 mL, 99%, 1.125 mol). The resulting mixture
was
allowed to warm up to room temperature and then washed with water (600 mL), 1
M
CA 02268590 1999-04-12
79
HCl aqueous solution (580 mL) and water (400 mL). The organic layer was dried
over
sodium sulfate and concentrated in vacuo to leave 54.5 g of amber oil, which
was
further pumped under high vacuum with stirring at room temperature for 25 min.
to
give 52.08 g (5.6% over theoretical yield) of the crude title compound
suitable for the
next step without any further purification.
(iii) 7-Benzyloxycarbonyl-1,4-dioxa-7-azaspiro[4.41nonane:
A mixture of N-benzyloxycarbonyl-3-pyrrolidinone (51.98 g, step ii, no more
than
224.9 mmol) and ethylene glycol (18.8 mL, 99+%, 337.4 mmol) in toluene (180
mL)
with a catalytic amount ofp-toluenesulfonic acid monohydrate (1.04 g, 5.4
mmol) was
refluxed in a Dean & Stark apparatus for 16 hours. The reaction mixture was
then
diluted with more toluene (250 mL) and washed with saturated sodium
bicarbonate
aqueous solution (150 mL) and saturated sodium chloride aqueous solution (2 x
150
mL). The combined aqueous layers were back-extracted with toluene (100 mL).
The
combined organic layers were dried over sodium sulfate and concentrated in
vacuo to
leave 79.6 g of dark oil. The crude product was dissolved in ethanol (500 mL),
and
running it through a bed of activated carbon (80 g), decolorized the resulting
solution.
The charcoal was washed with more ethanol (1000 mL) and toluene (500 mL). The
filtrate was concentrated in vacuo and further pumped under high vacuum for 1
hour to
yield 63.25 g (6.8% over theoretical yield) of the crude title compound
suitable for the
next step without any further purification.
(iv) 1,4-Dioxa-7-azaspiro[4-44]nonane: A mixture of 7-
benzyloxycarbonyl-1,4-dioxa-7-azaspiro[4.4]nonane (34.79 g, step iii, no more
than
123.7 mmol) and 10% Pd-C (13.9 g) in ethanol (90 mL) was hydrogenolyzed (60
psi) in
a Parr shaker apparatus at room temperature for 1.5 hour. The catalyst was
filtered off,
the solvent was evaporated in vacuo and the residue was pumped under high
vacuum
for 20 min. to yield 15.86 g of the title compound (yield 99.3%).
(v) (1R,2R)/(1S,2S)-~1,4-Dioxa-7-azaspiro[4.4]non-7-
yl)cYclohexanol: A mixture of 1,4-dioxa-7-azaspiro[4.4]nonane (23.54 g, step
iv, no
more than 182 mmol), cyclohexene oxide (22.6 mL, 98%, 219 mmol) and water (7.8
mL) was heated at 80°C for 2 hours. The reaction mixture was then
partitioned between
CA 02268590 1999-04-12
40% sodium hydroxide aqueous solution (60 mL) and diethyl ether (120 mL). The
basic aqueous layer was extracted twice more with diethyl ether (2 x 120 mL).
The
combined organic extracts were dried over sodium sulfate and concentrated in
vacuo.
The residue was then pumped under high vacuum at 50 °C for 1 hour under
stirring (to
5 remove the excess of cyclohexene oxide) to yield 32.79 g of the crude title
compound
(yield 79.3%).
(vi) To a chilled (0°C) solution of (1R,2R)/(1S,2S)-2-(1,4-dioxa-7-
azaspiro[4.4]non-7-yl)cyclohexanol (27.47 g, 120 mmol, step v) and
triethylamine
(15.86 g, 156 mmol) in dichloromethane (240 mL) was added dropwise
10 methanesulfonyl chloride (18.23 g, 156 mmol). The reaction mixture was
stirred at 0°C
for 45 min. and then at room temperature for 3 hours. The reaction mixture was
then
washed with a mixture of water-saturated sodium bicarbonate aqueous solution
(l:l,
v/v, 120 mL). The washing layer was collected and was back-extracted with
dichloromethane ( 120 mL). The combined organic extracts were dried over
sodium
15 sulfate, the solvent was evaporated in vacuo and the residue was pumped
under high
vacuum for 4 hours to yield the crude mesylate suitable for the next step
without any
further purification.
(vii) To sodium hydride (4.32 g, 144 mmol) suspended in anhydrous
ethylene glycol dimethyl ether (80 mL) was added a solution of 1-
naphthenethanol
20 (25.31 g, 144 mmol) in anhydrous ethylene glycol dimethyl ether (80 mL).
The
resulting mixture was then stirred at room temperature for 4 hours.
(viii) (1R,2R)/(1S,2S)-2-[1,4-dioxa-7-azaspiro[4.4]non-7-~l-1-(1-
naphthenethoxy)cyclohexane: A solution of mesylate (vi) in anhydrous ethylene
glycol
dimethyl ether (80 mL) was added quickly to the alkoxide (vii) and the
resulting
25 mixture was readily heated to reflux under argon for 66 hours. The cooled
reaction
mixture was quenched with water (200 mL) and the organic solvent was
evaporated in
vacuo. The remaining aqueous solution was diluted with water (500 mL) and
acidified
with 10% HCl aqueous solution to pH 0.5. The acidic aqueous layer was
extracted with
diethyl ether (2 x 500 mL) in order to extract unreacted 1-naphthenethanol.
The pH of
30 the aqueous solution was adjusted to pH 4.8 with SM NaOH aqueous solution
and then
CA 02268590 1999-04-12
81
extracted with diethyl ether (600 mL). The aqueous solution was further
basified to pH
5.7 and extracted with diethyl ether (600 mL). The same procedure was repeated
at pH
6.5 and 12.1. Analysis by gas chromatography of the different ether extracts
showed
that organic extracts at pH 4.8, 5.7 and 6.5 contained the title compound
whereas ether
extract at pH 12.1 contained only unknown impurities. The organic extracts at
pH 4.8,
5.7 and 6.5 were combined and dried over sodium sulfate. The solvent was
evaporated
in vacuo and the residue was pumped under high vacuum for 3.5 hours to yield
35.82 g
(75% yield) of the title compound suitable for the next step without any
further
purification.
(ix) (1R,2R)/(1S,2S)-2-(3-Ketopyrrolidin~)-1-(1-
naphthenethoxy)cyclohexane monc~hydrochloride: A solution of ( 1 R,2R)/( 1 S,2
S)-2-
[1,4-dioxa-7-azaspiro[4.4]non-7-yl]-1-(1-naphthenethoxy)cyclohexane (13.73 g,
36.0
mmol, step vi) with 6M HCl aqueous solution (50 mL) in 2-butanone (200 mL) was
refluxed for 12 hours. The butanone was evaporated in vacuo and the residual
aqueous
solution was diluted to 250mL with water. The aqueous solution was extracted
with
diethyl ether (2 x 200 mL) and then with dichloromethane (2 x 200 mL). The
pooled
dichloromethane extracts were dried over sodium sulfate and the solvent was
evaporated in vacuo. The residual oil was azeotropically dried with toluene.
The
resulting sticky product was vigorously stirred overnight in diethyl ether
(500 mL) with
occasional scratching to trigger crystallization of the reaction product. The
resulting
solid was collected and solubilized in a small amount of dichloromethane (~10
mL),
addition of a large quantity of diethyl ether 0400 mL) triggered
recrystallization. The
solid was collected, dried under high vacuum for 3 hours to yield 9.3 g (76%
yield) of
the title compound, having the elemental analysis indicated in Table 1.
CA 02268590 1999-04-12
82
EXAMPLE 16
( 1 R,2R)/( 1 S,2S)-2-( 1-ACETYLPIPERAZINYL)-1-(2-NAPHTHENETHOXY)CYCLOHEXANE
MONOHYDROCHLORIDE
S (COMPOUND #16)
Compound #16 was prepared according to a procedure similar as the one
depicted in Figure 1 and further detailed in Example 14.
(i) (1R,2R)/(1S,2S)-2-(1-Acetylpiperazin~)-1-cyclohexanol: A
mixture of 1-acetylpiperazine (5 g, 39 mmol) and cyclohexene oxide (3.95 mL,
39
mmol) in water ( 1.2 mL) was refluxed for 16 hours. The cooled reaction
mixture was
partitioned between 40% NaOH aqueous solution (20 mL) and diethyl ether (2 x
20
mL). The combined organic layers were dried over sodium sulfate and the
solvent was
evaporated in vacuo to yield 7.63 g of the title compound as white crystals
(87% yield)
(ii) To a chilled (0°C) solution of (1R,2R)/(1S,2S)-2-(1-
acetylpiperazinyl)-1-cyclohexanol (3.65 g, 16.2 mmol) and triethylamine (3.4
mL, 24
mmol) in dichloromethane (50 mL) was added dropwise a solution of
methanesulfonyl
chloride (1.55 mL, 20 mmol) in dichloromethane (50 mL). The reaction mixture
was
stirred at 0°C for one hour and then allowed to warm up to ambient
temperature. The
reaction mixture was then washed with water (2 x 50 mL) and the combined
washings
were back-extracted with dichloromethane (50 mL). The combined organic layers
were
dried over sodium sulfate and the solvent was evaporated in vacuo to yield the
crude
mesylate suitable for the next step without any further purification.
(iii) To a suspension of sodium hydride (0.8 g, 24 mmol, previously
washed with hexanes (2 x 15 mL)) in anhydrous dimethylformamide (50 mL) was
added a solution of 2-naphthenethanol in anhydrous dimethylformamide (50 mL).
The
resulting mixture was stirred at room temperature for 30 min.
(iv) (1R,2R)/(1S,2S)-2-(1-Acetylpiperazinyl)-1-(2-
naphthenethoxy)cyclohexane monohydrochloride: the mesylate (ii) in solution in
anhydrous dimethylformamide (50 mL) was added quickly to the alkoxide mixture
(iii)
and the resulting mixture was heated to 80°C for 16 hours. The cooled
reaction mixture
CA 02268590 1999-04-12
83
was poured into ice water (800 mL) and extracted with ethyl acetate (3 x 200
mL). The
combined organic extracts were back-washed with brine (200 mL) and the solvent
was
evaporated in vacuo. The residual oil was taken up with water (80 mL) and the
resulting aqueous solution was acidified to pH 2 with 6M HCl aqueous solution.
The
acidic aqueous solution was extracted with diethyl ether (3 x 40 mL) in order
to extract
the unreacted 2-naphthenethanol. 'The pH of the aqueous layer was adjusted to
pHlO
with 50% NaOH aqueous solution and extracted with diethyl ether (3 x 40 mL).
The
combined organic extracts were dried over sodium sulfate and the solvent was
evaporated in vacuo to yield the crude free aminoether. Purification by column
chromatography of silica gel using a mixture of ethyl acetate-dichloromethane
(1:1, v/v)
as eluent provided the pure free base. Conversion to the hydrochloride salt
was
accomplished with ethereal HCl followed by recrystallization in a mixture of
ethanol-
diethyl ether provided the title compound, having the elemental analysis
indicated in
Table 1.
EXAMPLE 17
(1R,2R)/(1 S,2S)-2-(3-KETOPYRROLIDINYL)-1-(2,6
DICHLOROPHENETHOXY)CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND # 17)
Compound #17 was prepared in 10 steps according to the procedure
described in Example 16. Steps (i) to (v) were identical to those in Example
16.
(vi) To a chilled (0°C) solution of (1R,2R)/(1S,2S)-2-(1,4-dioxa-7-
azaspiro[4.4]non-7-yl)cyclohexanol (27.77 g, 120 mmol) and triethylamine (22
mL, 156
mmol) in dichloromethane (240 mL) was added methanesulfonyl chloride ( 12.32
mL,
156 mmol). The reaction mixture was stirred at 0°C for 45 min. and then
at room
temperature for 3 hours. The reaction mixture was washed with water (2 x 100
mL) and
the combined washings were back-extracted with dichloromethane (120 mL). The
combined organic extracts were dried over sodium sulfate and the solvent was
CA 02268590 1999-04-12
84
evaporated in vacuo to yield the crude mesylate which was further pumped under
high
vacuum for 4 hours prior to use in step ix.
(vii) 2,6-Dichlorophenethyl alcohol: a suspension of lithium
aluminum hydride (13.75 g, 365.75 mmol) in anhydrous diethyl ether (500 mL)
was
added via a powder addition funnel 2,6-dichlorophenylacetic acid (50 g, 243.75
mmol).
The resulting reaction mixture was refluxed for 16 hours and then quenched by
slow
addition of a sodium sulfate saturated aqueous solution (25 mL). The resulting
slurry
was stirred for 3 hours and then filtered, the insoluble was carefully washed
with diethyl
ether (2 x 100 mL). The combined ether filtrates were dried over sodium
sulfate and the
solvent was evaporated in vacuo to yield 38.6 g (85% yield) of the title
compound.
(viii) To sodium hydride (144 mmol, 4.32 g, 80% oil dispersion) in
anhydrous ethylene glycol dimethyl ether (80 mL) was added a solution of 2,6
dichlorophenethyl alcohol (27.65 g, 144 mmol) in anhydrous ethylene glycol
dimethyl
ether (80 mL). The resulting mixture was stirred at room temperature under
argon
atmosphere for 4 hours.
(ix) (1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiroj4.4]non-7-y~-1-(2,6-
dichlorophenethoxy)cyclohexane: The mesylate (vi) in anhydrous ethylene glycol
dimethyl ether (80 mL) was added quickly to the alkoxide mixture (viii) and
the
resulting mixture was readily refluxed for 66 hours. The cooled reaction
mixture was
poured into water (200 mL) and the organic solvent was evaporated in vacuo.
The
residual aqueous solution was diluted with more water to a volume of 700 mL,
acidified
to pH 0.5 with 6M HCl aqueous solution and extracted with diethyl ether (2 x
600 mL).
The pH of the aqueous layer was adjusted to pH 5.9 and then the aqueous
solution was
extracted with diethyl ether (700 mL). The organic extract was dried over
sodium
sulfate and the solvent was evaporated in vacuo to yield 34.0 g of the title
compound
(70% yield).
(x) ~1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-(2,6-
dichlorophenethoxy)cyclohexane monohydrochloride: A mixture of ( 1 R,2R)/( 1
S,2S)-2-
[1,4-dioxa-7-azaspiro[4.4]non-7-yl]-1-(2,6-dichlorophenethoxy)cyclohexane
(15.85 g,
38.9 mmol, step ix) and 6M HCl aqueous solution (100 mL) in 2-butanone (400
mL)
CA 02268590 1999-04-12
was refluxed for 16 hours. The cooled reaction mixture was diluted with water
(100
mL) and the organic solvent was evaporated in vacuo. The organic layer was
further
diluted with water (400 mL), extracted with diethyl ether (500 mL) and with
dichloromethane (2 x 600 mL). The combined dichloromethane extracts were dried
5 over sodium sulfate and the solvent was evaporated in vacuo. Azeotropic
distillation
with toluene provided the title compound which was further dried under high
vacuum
for 15 min. The hydrochloride salt was crystallized by triturating in diethyl
ether, the
crystals were collected and recrystallized from a mixture of ethanol-diethyl
ether to
yield 11.85 g of pure product (77% yield), having the elemental analysis
indicated in
10 Table 1.
EXAMPLE 18
( 1 R,2R)/( 1 S,2S)-2-[ 1,4-DIOXA-7-AZasPIRO[4.4]NON-7-YL]-1-( 1-
15 NAPHTHENETHOXY)CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND # 18)
( 1 R,2R)/( 1 S,2S)-2-[ 1,4-Dioxa-7-azaspiro [4.4]non-7-yl]-1-( 1-
naphthenethoxy)cyclohexane (1.2 g, 3.14 mmol, from Example 15, step (viii)) in
20 diethyl ether (80 mL) was treated with ethereal HCI. The solvent was
evaporated in
vacuo and the residue was taken up with diethyl ether, triturating gave a
solid, which
was collected and precipitated from a mixture of dichloromethane-diethyl ether
to yield
0.85 g of the title compound, having the elemental analysis indicated in Table
1.
CA 02268590 1999-04-12
86
EXAMPLE 19
( 1 R,2S)/( 1 S,2R)-2-(4-MORPHOLINYL)-1-[(2
TRIFLUOROMETHYL)PHENETHOXY~CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND # 19)
(i) 2-(4-Morpholin~)cyclohexanone: To a chilled (-70°C) solution
of oxalyl chloride (20 mL, 0.23 mol) in dichloromethane (500 mL) was added
dropwise
a solution of anhydrous dimethylsulfoxide (34 mL, 0.48 mol) in dichloromethane
(50
mL) and the resulting mixture was stirred for 5 min. at a temperature below -
60°C.
Then a solution of (1R,2R)/(1S,2S)-2-(4-morpholinyl)cyclohexanol (37.05 g, 0.2
mol)
in dichloromethane (50 mL) was added dropwise in order to maintain the
reaction
temperature below -60°C and the reaction mixture was stirred for 15
min.
Triethylamine (140 mL) was added dropwise to the reaction mixture, keeping the
reaction temperature below -50°C, and then the reaction mixture was
allowed to warm
up to room temperature. The reaction mixture was poured into water (600 mL)
and the
aqueous layer was separated and extracted with dichloromethane (2 x 500 mL).
The
combined organic layers were dried over sodium sulfate and the solvent was
removed in
vacuo. Vacuum distillation yielded 35.1 g (96% yield) of the title compound.
(ii) 2-(4-Morpholin~l~yclohexanol: To a chilled (0°C) suspension of
sodium borohydride (2.14 g, 56 mmol) in isopropanol (120 mL) was added a
solution of
2-(4-morpholinyl)cyclohexanol (24.7 g, 135 mmol, step i) in isopropanol (80
mL). The
resulting reaction mixture was stirred at 0°C for 10 min. and then 30
min. at ambient
temperature. Water (200 mL) was added to the reaction mixture and the organic
solvent
was evaporated in vacuo. The residual aqueous solution was then extracted with
ethyl
acetate (4 x 50 mL), the combined organic extracts were dried over sodium
sulfate and
the solvent was evaporated in vacuo to yield 22.48 g of the title compound
suitable for
the next step without any further purification.
(iii) ( 1 S,2R)/( 1 R1ZS)-2-(4-Morpholinyl)cyclohexyl
2-(trifluoromethyl~phenylacetate: A mixture of 2-(4-morpholinyl)cyclohexanol
(7.41 g,
mmol, step ii), 2-(trifluoromethyl)phenylacetic acid (10.21 g, 49 mmol) and p-
CA 02268590 1999-04-12
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toluenesulfonic acid monohydrate (40 mg) in toluene (60 mL) was refluxed in a
Dean &
Stark apparatus for 48 hours. To the cooled reaction mixture was added
saturated
sodium bicarbonate aqueous solution (40 mL), the aqueous layer was separated
and
extracted with ethyl acetate (3 x 50 mL). The combined organic layers were
dried over
sodium sulfate and the solvent was evaporated in vacuo to yield a mixture of
( 1 S,2R)/( 1 R,2S)-2-(4-morpholinyl)cyclohexyl 2-
(trifluoromethyl)phenylacetate and
(1R,2R)/(1 S,2S)-2-(4-morpholinyl)cyclohexyl 2-(trifluoromethyl)phenylacetate.
Chromatography by dry column of the cisltrans mixture with mixtures of ethyl
acetate-
hexanes (+ 0.5% isopropylamine v/v) as eluents provided 3.19 g of the crude
title
compound contaminated by the starting material 2-(4-morpholinyl)cyclohexanol.
The
crude product was partitioned between dichloromethane (30 mL) and O.SM HCl
aqueous solution (7 mL). The aqueous layer was separated and further extracted
with
dichloromethane (2 x 18 mL). The combined organic layers were dried over
sodium
sulfate and the solvent was evaporated in vacuo. Recrystallization from a
mixture of
ethanol-hexanes yielded 2.78 g of the title compound.
(iv) (1S,2R)/(1R,2S)-2-(4-Mor~holinyl)-1-[(2-
trifluoromethyl)phenethoxy]cyclohexane monohydrochloride: To a mixture of
( 1 S,2R)/( 1 R,2S)-2-(4-morpholinyl)cyclohexyl 2-
(trifluoromethyl)phenylacetate ( 1.64 g,
4.28 mmol, step iii) and sodium borohydride (332 mg, 8.70 mmol) in anhydrous
tetrahydrofuran (35 mL) under reflux was added a solution of boron trifluoride
diethyl
etherate (8.2 mL, 65 mmol) over 1.5 hour. The reaction mixture was quenched by
addition of water (~70 mL), the organic solvent was evaporated in vacuo and
the pH of
the residual aqueous solution was adjusted to pH 9.6. The aqueous layer was
extracted
with diethyl ether (2 x 70 mL), the combined organic extracts were dried over
sodium
sulfate and the solvent was evaporated in vacuo. The residue was then
partitioned
between O.SM HCl aqueous solution (50 mL) and diethyl ether (2 x 50 mL). The
aqueous solution was basified to pH 5.9 and extracted with diethyl ether (50
mL). The
organic layer was collected, dried over sodium sulfate and the solvent was
evaporated in
vacuo to yield the crude free aminoether. The free base was converted to the
hydrochloride salt by partition between O.SM HCl aqueous solution (10 mL) and
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dichloromethane ( 10 mL). The acidic aqueous solution was extracted once more
with
dichloromethane (10 mL), the combined organic extracts were dried over sodium
sulfate and the solvent was evaporated in vacuo. Recrystallization from a
mixture of
ethanol-hexanes yielded 636 mg (38% yield) of the title compound, having the
elemental analysis indicated in Table 1.
EXAMPLE 20
( 1 R,2R)/( 1 S,2S)-2-(3-KETOPYRROLIDINYL)-1-[3-
1 O (CYCLOHEXYL)PROPOXY]CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND #20)
(i) 3-C cl~yl-1-propyl bromide: To the chilled (0°C) 3-
cyclohexyl-1-propanol (5 g, 35.15 mmol) was added slowly a solution of
phosphorus
tribromide ( 1.1 mL, 17.6 mmol) in dichloromethane (2 mL). Upon completion of
the
addition, the reaction mixture was allowed to warm up to room temperature and
was
stirred for 4 hours. The reaction was quenched by addition of saturated sodium
bicarbonate aqueous solution (5 mL) and 10% NaOH (10 mL). The resulting
mixture
was extracted with diethyl ether (3 x 50 mL), the combined organic extracts
were dried
over sodium sulfate and the solvent was evaporated in vacuo to provide an oil.
Vacuum
distillation yielded 3.4 g (47% yield) of the title compound.
(ii) (1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiro[4.4]non-7-~l-1-[3-
(cyclohexyl)propoxy]cyclohexane: To a suspension of sodium hydride (200 mg,
8.33
mmol) in anhydrous dimethylformamide (20 mL) was added a solution of
(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol (1.5 g, 6.6
mmol)
in anhydrous dimethylformamide (10 mL). The resulting mixture was stirred at
room
temperature for 30 min. and then a solution of 3-(cyclohexyl)propyl bromide
(1.67 g,
8.15 mmols) in anhydrous dimethylformamide was quickly added. The reaction
mixture was stirred at room temperature for 16 hours. The reaction mixture was
poured
into water (200 mL) and then extracted with ethyl acetate (3 x 50 mL). The
combined
organic extracts were back-washed with brine (50 mL) and the solvent was
evaporated
CA 02268590 1999-04-12
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in vacuo. The residue was taken up with water (50 mL) and the pH was adjusted
to pH
1.0 with 6M HCl aqueous solution. The acidic aqueous solution was extracted
with
diethyl ether (2 x 50 mL), then basified to pH 5.0-5.5 with SM NaOH aqueous
solution
and extracted with diethyl ether (3 x 50 mL). The combined organic extracts at
pH 5.0-
5.5 were concentrated in vacuo to provide the crude title compound suitable
for the next
step without any further purification.
(iii) (1R,2S~1S,2R)-2-(3-Ketopyrrolidinyl)-1-[3-
wclohex~l,)propoxylcyclohexane monohydrochloride: (1R,2R)/(1S,2S)-2-[1,4-Dioxa-
7-azaspiro[4.4]non-7-yl]-1-[3-(cyclohexyl)propoxy]cyclohexane (ii) in a
mixture of 6M
HCl aqueous solution-butanone (1:4, v/v, 100 mL) was refluxed for 16 hours.
The
cooled reaction mixture was concentrated in vacuo and the residual aqueous
solution
was diluted with water (~50 mL). The acidic aqueous solution was extracted
with
diethyl ether (50 mL) and then with dichloromethane (3 x 50 mL). The
dichloromethane extracts were dried over sodium sulfate and the solvent was
evaporated in vacuo to provide the crude title compound. The hydrochloride
salt was
crystallized by triturating in a mixture of diethyl ether-hexanes (1:1, v/v,
200 mL) and
then precipitated from a mixture of dichloromethane-diethyl ether-hexanes to
yield 0.8
g of the title compound, having the elemental analysis indicated in Table 1.
EXAMPLE 21
( 1 R,2R)/( 1 S,2 S)-2-(3-ACETOXYPYRROLIDINYL)-1-( 1-
NAPHTHENETHOXY)CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #21)
(i) (1R,2R)/(1S,2S,-2-y3-Hydroxypyrrolidinyll-1-(1-
naphthenethoxy)cyclohexane monohydrochloride: To a chilled (0°C)
solution of sodium
borohydride in isopropanol (20 mL) was added a solution of (1R,2R)/(1S,2S)-2-
(3-
ketopyrrolidinyl)-1-(1-naphthenethoxy)cyclohexane monohydrochloride (1.4 g,
3.75
mmol) in isopropanol (30 mL). The resulting mixture was stirred at 0°C
for 15 min.
and then 30 min. at room temperature. The reaction was quenched by addition of
water,
CA 02268590 1999-04-12
the reaction mixture was evaporated to dryness and the residue was washed with
dichloromethane (2 x 20 mL). The dichloromethane washings were dried over
sodium
sulfate and the solvent was evaporated in vacuo to yield the title compound.
(ii) (1R,2R)/(1S,2S)-2-(3-Acetoxypyrrolidinyl)-1-(1-
5 naphthenethoxy)cyclohexane monohydrochloride: The intermediate alcohol (i)
was then
refluxed in acetic anhydride ( 15 mL) for 2 hours. The excess acetic anhydride
was
removed in vacuo; the residue was taken up with water (100 mL) and extracted
with
diethyl ether (2 x 30 mL). The aqueous solution was basified to pH 8.0 and
extracted
with diethyl ether (3 x 50 mL). The combined organic extracts were dried over
sodium
10 sulfate and concentrated in vacuo. The residual oil was dissolved in a
small amount of
dichloromethane and a large volume of diethyl ether was added in order to
trigger
crystallization of 1.0 g (65% yield) of the title compound, having the
elemental analysis
indicated in Table 1.
15 EXAMPLE 22
( 1 R,2R)/( 1 S,2S)-2-(4-MORPHOLINYL)-1-[(2,6
DICHLOROPHENYL)METHOXY~CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND #22)
Compound #22 was prepared according to the Williamson ether
synthesis. To a suspension of sodium hydride, 80% oil dispersion (337 mg, 11
mmol)
in ethylene glycol dimethyl ether (20 mL) was added a solution of
(1R,2R)/(1S,2S)-2-
(4-morpholinyl)-1-cyclohexanol (2.0 g, 10.8 mmol) in ethylene glycol dimethyl
ether
(10 mL). The resulting reaction mixture was stirred at room temperature under
argon
atmosphere for 3 hours, then a solution of 2,6-dichlorobenzyl bromide in
ethylene
glycol dimethyl ether (10 mL) was added and the reaction mixture was refluxed
for 16
hours. The cooled reaction mixture was poured into water (40 mL) and the
organic
solvent was evaporated in vacuo. The residual aqueous solution was diluted
with more
water (60 mL) and acidified to pH 0.5 with 6M HCl aqueous solution. The acidic
aqueous solution was extracted with diethyl ether (2 x 40 mL) and then the pH
was
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adjusted to pH 5.5. Extraction with diethyl ether (3 x 50 mL) followed by
drying over
sodium sulfate and concentration in vacuo provided the pure aminoether. The
hydrochloride salt was precipitated by treatment of the free base with
ethereal HCI.
Recrystallization from a mixture of acetone-methanol-diethyl ether yielded 2.6
g (68%
yield) of the title compound, having the elemental analysis indicated in Table
1.
EXAMPLE 23
( 1 R,2R)/( 1 S,2S)-2-(3-KETOPYRROLIDINYL)-1-[(2,6-
1 O DICHLOROPHENYL)METHOXY]CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND #23)
Compound #23 was prepared in 7 steps according to the procedure
detailed in Example 15. Steps (i) to (v) were identical to the ones described
in Example
15. The ether synthesis (step vi) was carried out according to the Williamson
ether
synthesis as in Example #22.
(vi) ( 1 R,2R)/( 1 S,2S)-2-[ 1,4-Dioxa-7-azaspiro [4.4]non-7-~l-1-[(2,6-
dichlorophenyl)methoxyl cyclohexane: To a suspension of sodium hydride, 80%
oil
dispersion (222 mg, 7.25 mmol) in ethyleneglycol dimethyl ether (20 mL) was
added a
solution of (1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol
(1.5 g,
6.60 mmol, step (v) of Example 15) in ethylene glycol dimethyl ether (10 mL).
The
resulting mixture was stirred at room temperature for 2 hours and then a
solution of 2,6-
dichlorobenzyl bromide ( 1.9 g, 7.9 mmol) in ethylene glycol dimethyl ether (
10 mL)
was added. The reaction mixture was refluxed for 16 hours under argon
atmosphere,
the solvent was evaporated in vacuo and the residue was taken up with water
(70 mL).
The aqueous solution was acidified to pH 0.5 with 6M HCl aqueous solution and
then
extracted with diethyl ether (2 x 40 mL). Basification of the aqueous solution
to pH
4.5-5.5, followed by extraction with diethyl ether (4 x 40 mL), drying of the
combined
organic extracts over sodium sulfate and evaporation of the solvent in vacuo
provided
the intermediate title compound.
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92
(vii) (1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-~(2,6-
dichlorophenyl)methoxy]cyclohexane monohydrochloride: The ketal intermediate
(step
vi) in a mixture of 6M HCl-butanone ( 1:4, v/v, 100 mL) was refluxed for 16
hours. The
butanone was evaporated in vacuo and the residual aqueous layer was diluted
with more
S water ( 100 mL). The acidic aqueous layer was extracted with diethyl ether
(2 x40 mL)
and then with dichloromethane (3 x 40 mL). The combined dichloromethane
extracts
were dried over sodium sulfate and the solvent was evaporated in vacuo to
provide the
crude title compound. The product was crystallized by triturating in diethyl
ether and
reprecipitated from a mixture of dichloromethane-diethyl ether to yield 1.8 g
(72%
yield) of the title compound, having the elemental analysis indicated in Table
1.
EXAMPLE 24
( 1 R,2R)/( 1 S,2 S)-2-(3-HYDROXYPYRROLIDINYL)-1-(2,6-
1 S DICHLOROPHENETHOXY)CYCLOHEXANE MONOHYDROCHLORIDE
(COMPOUND #24)
To a solution of compound #17 (S.0 g, 12.7 mmol) in isopropanol (120
mL) was added sodium borohydride (2.0 g, 52.8 mmol) as a powder and the
resulting
mixture was stirred at room temperature until completion of the reaction. The
reaction
was quenched with water (40 mL) and then concentrated to dryness. The residue
was
washed with dichloromethane (SO mL); the filtrate was dried over sodium
sulfate,
concentrated in vacuo to provide the title compound, which crystallized after
3 hours
under high vacuum. Elemental analysis results of the product is shown in Table
1.
2S
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EXAMPLE 25
( 1 R,2R)/( 1 S,2S)-2-(3-KETOPYRROLIDINYL)-1-(2,2-DIPHENYLETHOXY)CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #25)
Compound #25 was prepared in 10 steps according to a procedure
identical to the one described in Examples 15 and 17. Steps (i) to (v) were
identical to
Example 15.
(vi) To a chilled (0°C) solution of (1R,2R)/(1S,2S)-2-(1,4-dioxa-7-
azaspiro[4.4]non-7-yl)cyclohexanol (2.0 g, 8.8 mmol) and triethylamine (2.1
mL, 15
mmol) in dichloromethane (30 mL) was added methanesulfonyl chloride (0.9 mL,
11.44
mmol). The reaction mixture was stirred at 0°C for 45 min. and then at
room
temperature for 3 hours. The reaction mixture was diluted with dichloromethane
(25
mL), washed with water (2 x 25 mL) and the combined washings were back-
extracted
with dichloromethane (25 mL). The combined organic extracts were dried over
sodium
sulfate and the solvent was evaporated in vacuo to yield the crude mesylate
which was
further pumped under high vacuum for 30 min. prior to use in step ix.
(vii) (2,2-Diphenyl)ethyl alcohol: To lithium aluminum hydride
(2.85 g, 23.56 mmol) in anhydrous diethyl ether (150 mL) was added, as a
powder,
diphenylacetic acid (5.0 g, 56 mmol). The resulting reaction mixture was
gently
refluxed for one hour. The reaction was quenched with sodium sulfate saturated
aqueous solution and the resulting precipitate was filtered off. The filtrate
was
concentrated in vacuo to yield 4.0 g (86% yield) of the title compound.
(viii) To sodium hydride, previously washed with hexanes, (253 mg,
10.56 mmol) in suspension in ethylene glycol dimethyl ether (15 mL) was added
a
solution of 2,2-diphenylethyl alcohol (2.09 g, 10.56 mmol, step vii) in
ethylene glycol
dimethyl ether (15 mL). The resulting mixture was stirred at room temperature
under
argon atmosphere for 30 min.
(ix) ( 1 R,2R)/( 1 S,2 S)-2-( 1,4-Dioxa-7-azas~iro [4.4]non-7-yl)-1-(2,2-
diphenylethoxy)cyclohexane: The mesylate (vi) in ethylene glycol dimethyl
ether (20
mL) was added quickly to the alkoxide (viii) and the reaction mixture was
refluxed for
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94
days. The cooled reaction mixture was concentrated in vacuo, the residue was
taken
up with water (50 mL) and the pH was adjusted to pH 1.0 with 6M HCl aqueous
solution. The acidic aqueous solution was extracted with diethyl ether (2 x 50
mL), the
aqueous layer was collected and basified to pH 6Ø Extraction with diethyl
ether (2 x
5 50 mL) followed by drying over sodium sulfate and evaporation of the solvent
in vacuo
yielded 1.55 g (43% yield) of the title compound.
(x) ,~1R,2R)/(1S,2S1-~3-Ketopyrrolidin~)-1-(2,2-
diphenylethoxy)cyclohexane monohydrochloride: A mixture of (1R,2R)/(1S,2S)-2-
(1,4-
dioxa-7-azaspiro[4.4]non-7-yl)-1-(2,2-diphenylethoxy)cyclohexane (1.55 g, 3.8
mmol)
in 6M HCl-butanone (1:4, v/v, 50 mL) was refluxed for 2 hours. The butanone
was
evaporated in vacuo and the residue was taken up with water (50 mL). The
aqueous
solution was extracted with diethyl ether (2 x 50 mL); the aqueous layer was
collected
and extracted with dichloromethane (2 x 50 mL). The combined dichloromethane
extracts were dried over sodium sulfate and concentrated in vacuo to yield the
crude
title compound. The product was crystallized by triturating in diethyl ether
and
reprecipitated from a mixture of dichloromethane-diethyl ether to yield 1.21 g
(80%
yield) of the title compound, having the elemental analysis indicated in Table
1.
EXAMPLE 26
( 1 R,2R)/( 1 S,2S)-2-(3-THIAZOLIDINYL)-1-(2,6-DICHLOROPHENETHOXY)CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #26)
(i) (1R,2R)/(1S,2S)-2-(3-Thiazolidinyl)cyclohexanol: To anhydrous
magnesium perchlorate (12.93 g, 53.3 mmol) was added a solution of cyclohexene
oxide (6.1 mL, 58.6 mmol) in anhydrous acetonitrile (25 mL) and the resulting
mixture
was stirred at room temperature for 20 min. Then a solution of thiazolidine
(5.16 g,
55.0 mmol) in anhydrous acetonitrile was added and the reaction mixture was
heated at
35°C for 16 hours. The reaction mixture was concentrated in vacuo and
the residue was
partitioned between water (350 mL) and diethyl ether (350 mL). The aqueous
layer was
CA 02268590 1999-04-12
9$
separated and extracted once more with diethyl ether (350 mL). The combined
organic
extracts were dried over sodium sulfate and concentrated in vacuo to provide
the crude
product. The crude aminoalcohol was purified by dry-column chromatography with
a
mixture of ethyl acetate-hexanes (1:1, v/v) as eluent to yield 4.83 g (47%
yield) of the
title compound.
(ii) To a chilled (0°C) solution of ( 1 R,2R)/( 1 S,2S)-2-(3-
thiazolidinyl)cyclohexanol (3.17 g, 16.9 mmol) and triethylamine (3.08 mL,
22.0
mmol) in dichloromethane (30 mL) was added dropwise methanesulfonyl chloride
(1.74
mL, 22.0 mmol). The reaction mixture was stirred at 0°C for one hour
and then at
ambient temperature for 3 hours. The reaction mixture was diluted with
dichloromethane (20 mL) and washed with water (2 x 30 mL). The combined
washings
were back-extracted with dichloromethane (25 mL) and the combined organic
extracts
were dried over sodium sulfate. Evaporation of the solvent in vacuo yielded
the
mesylate suitable for the next step without any further purification.
(iii) To sodium hydride, 80% oil dispersion (608 mg, 20.28 mmol) in
ethylene glycol dimethyl ether (30 mL) was added a solution of 2,6-
dichlorophenethyl
alcohol (3.87 g, 20.28 mmol, example 4, step vii) in ethyleneglycol dimethyl
ether (15
mL). The resulting mixture was stirred at room temperature under argon
atmosphere
for 2 hours.
(iv) (1R,2R)/(1S,2S)-2-(3-Thiazolidin~)-1-(2,6-
dichlorophenethoxy)cyclohexane monohydrochloride: The mesylate (ii) in
ethylene
glycol dimethyl ether (15 mL) was added quickly to the alkoxide (iii) and the
reaction
mixture was refluxed for 40 hours. The cooled reaction mixture was poured into
water
(100 mL) and the organic solvent was evaporated in vacuo. The residual aqueous
solution was diluted with more water (100 mL) and the pH was adjusted to pH
1.5. The
acidic aqueous solution was extracted with diethyl ether (3 x 100 mL), the
combined
organic extracts were dried over sodium sulfate and the solvent was removed in
vacuo
to provide the crude free base. The product was purified by dry-column
chromatography with a mixture of ethyl acetate-hexanes (1:10, v/v) as eluent
to yield
2.4 g of the crude free aminoether. The pure product (1.0 g) was converted to
the
CA 02268590 1999-04-12
96
hydrochloride salt by treatment with ethereal HC1 and the resulting salt was
recrystallized from a mixture of acetone-diethyl ether to yield 0.69 g of the
title
compound, having the elemental analysis indicated in Table 1.
EXAMPLE 27
( 1 R,2 S)/( 1 S,2R)-2-(3-KETOPYRROLIDINYL)-1-( 1-NAPHTHENETHOXY)CYCLOHEXANE
MONOHYDROCHLORIDE
(COMPOUND #27)
Compound #27 was prepared in 8 steps according to the synthetic
scheme depicted in Figure 3. Steps (i) to (iv) were identical to those
described in
Example 15.
(v) ( 1 R,2R)/( 1 S,'ZS)-1-( 1-Naphthenethoxy)-2-cyclohexanol: To
anhydrous magnesium perchlorate (270 mg, 1.2 mmol) in anhydrous acetonitrile
(1.7
mL) was added cyclohexene oxide (0.12 g, 1.2 mmol). The resulting mixture was
stirred for 15 min. at room temperature and then 1-naphthenethanol (2.7 g,
10.15 mmol)
was added. The reaction mixture was refluxed and more cyclohexene oxide (2.0
mL,
2.0 g, 20 mmol) was added to the refluxing reaction mixture at a rate of 0.4
mL/hour.
Reflux was stopped after 16 hours and the cooled reaction mixture was
partitioned
between diethyl ether (50 mL) and saturated sodium bicarbonate aqueous
solution (30
mL). The aqueous layer was separated and extracted twice more with diethyl
ether (2 x
40 mL). The combined organic extracts were back-washed with water ( 15 mL),
brine
( 15 mL) and dried over sodium sulfate. Evaporation of the solvent in vacuo
yielded the
crude title compound suitable for the next step without any further
purification.
(vi) 1-(1-Naphthenethoxy)-2-cyclohexanone: To a solution of
(1R,2R)/(1S,2S)-2-(1-naphthenethoxy)-1-cyclohexanol (1.0 g, step v) in
dimethylformamide (20 mL) was added pyridinium dichromate (5.0 g, 13.2 mmol)
in
small portions and the resulting reaction mixture was stirred at room
temperature for 16
hours. The reaction mixture was poured into water (100 mL) and the resulting
slurry
was extracted with diethyl ether (3 x 50 mL). The combined organic extracts
were
CA 02268590 1999-04-12
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back-washed with 1M NaOH aqueous solution (30 mL), brine (30 mL) and dried
over
sodium sulfate. Evaporation of the solvent provided 1.0 g of the crude title
compound
suitable for the next step of the reaction.
(vii) (1R,2S)/(1S,2R)-2-(1,4-Dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-
naphthenethoxy)cyclohexane: To a solution of 1,4-dioxa-7-azaspiro[4.4]nonane
(5.17 g,
40 mmol) and 1-( 1-naphthenethoxy)-2-cyclohexanone ( 1.79 g, 6.58 mmol, step
vi, 77%
pure) in anhydrous methanol (10 mL) was added SN HCl methanolic solution (2.7
mL)
and then sodium cyanoborohydride (397 mg, 6 mmol). The reaction mixture was
further diluted with anhydrous methanol (7 mL) and stirred at room temperature
for 16
hours. The reaction mixture was quenched by addition of 6M HCl aqueous
solution (40
mL), the organic solvent was evaporated in vacuo, the residual aqueous
solution was
diluted to 100 mL with water and the pH was adjusted to pH 0.5 with 6M HCl
aqueous
solution. The acid aqueous layer was extracted with diethyl ether ( 100 mL);
the
aqueous layer was separated and basified to pH 6.7 with SM NaOH aqueous
solution.
Extraction with diethyl ether (100 mL), followed by drying over sodium sulfate
and
evaporation of the solvent in vacuo provided, after purification by dry-column
chromatography with mixtures of ethyl acetate-hexanes (1:9 to 1:6, v/v, +0.5%
v/v
isopropylamine) as eluents, 1.28 g of crude (1R,2S)/(1S,2R)-2-(1,4-dioxa-7-
azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexane and (1R,2R)/(1S,2S)-2-
(1,4-
dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexane. Separation of
( 1 R,2S)/( 1 S,2R)-2-( 1,4-dioxa-7-azaspiro [4.4]non-7-yl)-1-( 1-
naphthenethoxy)cyclohexane from (1R,2R)/(1S,2S)-2-(1,4-dioxa-7-
azaspiro[4.4]non-7-
yl)-1-(1-naphthenethoxy)cyclohexane was performed by preparative HPLC (Waters
Delta Prep 4000, PrePak cartridge 40 x 100 mm, isopropanol-hexanes (2:98, v/v,
+
0.05% v/v diethylamine)) to yield 590 mg of the title compound.
viii) ,(1R,2S)/(1S,2R1-2-(3-Ketop rr~nyl)-1-(1-
naphthenethoxy)cyclohexane monohydrochloride: A mixture of (1R,2S)/(1S,2R)-2-
(1,4-dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexane (480 mg,
1.23
mmol, step vii) in 6M HCl aqueous solution-butanone (1:4, v/v, 40 mL) was
refluxed
for 2 hours. The organic solvent was evaporated in vacuo, the residual aqueous
solution
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was diluted to 50 mL with water and extracted twice with diethyl ether (2 x 50
mL) and
then thrice with dichloromethane (3 x 50 mL). The combined dichloromethane
extracts
were dried over sodium sulfate and the solvent was evaporated in vacuo, the
residual oil
was further dried by azeotropic distillation of toluene. The title compound
was
crystallized by triturating in hexanes (430 mg, 93% yield), and has elemental
analysis
indicated in Table 1.
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Table 1
CompoundFormula Calculated Found
#1 CzzH3NOZCI C 70.29, H 8.04, C 69.36, H 8.17,
N 3.73% N 3.73%
#2 CzzHsoNOzCI C 70.29, H 8.04, C 69.78, H 8.06,
N 3.73% N 3.56%
#3 C,BHz~NO2BrClC 53.41, H 6.72, C 53.16, H 6.77,
N 3.46% N 3.35%
#4 CzzHaoNOaCI C 67.42, H 7.72, C 67.31, H 7.75,
N 3.57% N 3.59%
#5 C,BHz,N03BrC1C 51.38, H 6.47, C 51.38, H 6.21,
N 3.33% N 3.28%
#6 CzoH3zNO4C1 C 62.24, H 8.36, C 61.69, H 8.64,
N 3.63% N 3.63%
#7 CzzH3oNOC1 C 73.41, H 8.40, C 73.26, H 8.64,
N 3.89% N 3.94%
#8 CzoHzBNOzSCI C 62.89, H 7.39, C 61.94, H 7.42,
N 3.67% N 3.70%
#9 CzoHzBNOzSCI C 62.89, H 7.39, C 62.53, H 7.56,
N 3.67% N 3.64%
#10 C,SHz,NO2BrC1C 53.41, H 6.72, C 53.29, H 6.94,
N 3.46% N 3.57%
#11 C,gHz,NOzBrCIC 53.41, H 6.72, C 52.61, H 7.46,
N 3.46% N 4.01%
#12 Cz,H34NO4C1 C 63.06, H 8.57, C 62.45, H 8.41,
N 3.50% N 3.45%
#14 C,aHz6NO2C13 C 54.77, H 6.64, C 58.80, H 6.85,
N 3.55% N 3.51%
#15 CzzHzBNOZC1 C 70.67, H 7.55, C 70.12, H 7.55,
N 3.75% N 3.73%
#16 Cz4HssN20zC1.Hz0C 63.63, H 8.23, C 62.93, H 8.56,
N 6.18% N 6.05%
#17 C,BHz4NOZC13 C 55.05, H 6.16, C 54.39, H 6.30,
N 3.57% N 3.49%
#18 Cz4H3zN03C1 C 68.97, H 7.72, C 68.49, H 7.64,
N 3.35% N 3.31%
#19 C,9Hz,NO2C1F3C 57.94, H 6.91, C 57.75, H 6.91,
N 3.56% N 3.56%
#20 C,9H34NOZCl C 66.35, H 9.96, C 66.22, H 9.72,
N 4.07% N 4.12%
#21 Cz4H3zN03Cl C 68.97, H 7.72, C 67.52, H 7.99,
N 3.35% N 3.17%
#22 Cl,Hz4NO2Clz.C 51.21, H 6.57, C 51.03, H 6.57,
H20 N 3.51% N 3.36%
#23 C,~HzzNOZCIz C 53.91, H 5.86, C 53,88, H 5.79,
N 3.70% N 3.59%
#24 C,8Hz6NO2C13.C 52.38, H 6.84, C 53.98, H 7.24,
H20 N 3.39% N 3.33%
#25 Cz4H3oNO2C1 C 72.07, H 7.56, C 71.87, H 7.57,
N 3.50% N 3.51%
#26 C"Hz4NOC13S C 51.46, H 6.10, C 51.48, H 5.86,
N 3.53% N 3.44%
#27 CzzHz8NO2C1 C 70.67, H 7.55, C 70.63, H 7.53,
N 3.75% N 3.65%
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EXAMPLE 28
ASSESSMENT OF ANTIARRHYTHMIC EFFICACY
Antiarrhythmic efficacy was assessed by investigating the effect of a
compound on the incidence of cardiac arrhythmias in conscious rats subject to
coronary
artery occlusion. Rats weighing 200-300 gms were subjected to preparative
surgery and
assigned to groups in a random block design. In each case, the animal was
anesthetized
with halothane during surgical preparation. The left femoral artery was
cannulated for
measurement of mean arterial blood pressure and withdrawal of blood samples.
The
left femoral vein was also cannulated for injection of drugs. The thoracic
cavity was
opened and a polyethylene occluder loosely placed around the left anterior
descending
coronary artery. The thoracic cavity was then closed. ECG was recorded by
insertion
of electrodes placed along the anatomical axis of the heart. All cannulae and
electrode
leads were exteriorized in the mid scapular region. In a random and double-
blind
manner, about 0.5 to 2 hours post-surgery, an infusion of vehicle, or the
compound to
be tested was given. After 15 minutes infusion, the occluder was pulled so as
to
produce coronary artery occlusion. ECG, arrhythmias, blood pressure, heart
rate and
mortality were monitored for 30 minutes after occlusion. Arrhythmias were
recorded as
ventricular tachycardia (VT) and ventricular fibrillation (VF) and scored
according to
Curtis, M.J. and Walker, M.J.A., Cardiovasc. Res. 22:656 (1988) (see Table 2).
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Table 2
Score Description
0 0-49 VPBs
1 50-499 VPBs
2 >499 VPBs and/or 1 episode of spontaneously reverting
VT or VF
3 >1 episode of VT or VF or both (>60s total combined
duration)
4 VT or VF or both (60-119s total combined duration)
S VT or VF or both (> 119s total combined duration)
6 fatal VF starting at > 15 min after occlusion
7 fatal VF starting at between 4 min and 14 min 59s
after occlusion
8 fatal VF starting at between 1 min and 3 min 59s
after occlusion
9 fatal VF starting < 1 min after occlusion
Where: VPB = ventricular premature beats
VT = ventricular tachycardia
VF = ventricular fibrillation
Rats were excluded from the study if they did not exhibit pre-occlusion
serum potassium concentrations within the range of 2.9-3.9 mM. Occlusion is
associated with increases in R-wave height and "S-T" segment elevation; and an
occluded zone (measured after death by cardiogreen dye perfusion) in the range
of
25%-50% of total left-ventricular weight.
Table 3 describes the result of tests of the compounds described therein
as values of a given infusion rate in micromol/kg/min. (EDS°AA) which
will reduce the
arrhythmia score in treated animals to 50% of that shown by animals treated
only with
the vehicle in which the test drugs) is dissolved.
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Table 3
Compound EDSOAA
#1 0.8
#2 1.0
#3 2.1
#4 2.0
#5 3.0
#6 4.0
#7 4.0
#8 1.0
#9 1.0
#10 2.0
#11 1.0
#14 1.5
# 15 0.43
#17 1.1
#19 1.4
#21 1.4
#22 1.8
#23 2.1
#24 0.6
#25 2.5
#26 I .. - 6.5
EXAMPLE 29
MEASUREMENT OF ECG PARAMETERS
Rats weighing 200-250 gms were used in this example. Animals were
anesthetized with 60 mg/kg pentobarbitone i.p. The carotid artery and jugular
vein
were cannulated for measurement of blood pressure and drug injection,
respectively.
ECG was recorded by insertion of electrodes placed along the anatomical axis
of the
heart. All compounds were given as bolus injections.
Various ECG parameters were measured. Table 4 describes the results of
the tests as ED25 (micromol/kg) which are the doses required to produce a 25%
increase
in the parameter measured (ne = not estimated). The increases in P-R interval
and QRS
interval indicate cardiac sodium channel blockage while the increase in Q-T
interval
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indicates ancillary cardiac potassium channel blockage which is the property
of a type
1 a antiarrhythmic.
Table 4
Compound PR QRS ~ QT
# 1 NE NE 2.5
#2 5.6 8 2.0
#3 32 16 3.0
#6 NE NE NE
#7 1.1 1.5 0.9
#14 - 21.5 1.4
#15 15.8 7.8 3.4
#17 30 26 4.2
#21 1.7 2.3 1.6
#23 - 17.2 2.7
#24 1.4 1.6 1.0
#26 2.3 - 10
EXAMPLE 30
ASSESSMENT OF SODIUM CHANNEL BLOCKAGE
Rats were prepared according to the preceding procedure. Two silver
stimulating electrodes were inserted through the chest wall and implanted in
the left
ventricle. Square wave stimulation was used to determine threshold current for
capture,
ventricular fibrillation threshold current, and effective refractory period
(Howard, P.G.
and Walker, M.J.A., Proc. West. Pharmacol. Soc. 33:123-127 (1990)). Table 5
contains
ED25 values for these indices of cardiac sodium channel blockage, where the
EDZS is the
infusion rate in micromol/kg/minute of compound required to elicit a 25%
increase
from control. The increases in refractoriness indicate ancillary blockage of
potassium
channels. The threshold current for capture is represented by "It". The
fibrillation
threshold current is represented by "VFT". The effective refracting period is
represented by "ERP"
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Table 5
Compound It VFT ERP
# 1 2.8 1.4 1.5
#2 0.9 0.7 1.3
#3 5.8 NE 4.0
#7 0.7 0.2 0.4
# 14 6.4 - 1.7
#15 5 1.2 1.6
# 17 6 7.3 7.1
#23 7.6 6.2 5
#24 1.7 1.2 1.1
#26 10.5 ~ 9 5.4
EXAMPLE 31
S CANINE VAGAL-AF MODEL
General methods
Mongrel dogs of either sex weighing 15-49 kg were anesthetized with
morphine (2 mg/kg im initially, followed by 0.5 mg/kg IV every 2 h) and a,-
chloralose
(120 mg/kg IV followed by an infusion of 29.25 mg/kg/h; St.-Georges et al.,
1997).
Dogs were ventilated mechanically with room air supplemented with oxygen via
an
endotracheal tube at 20 to 25 breaths/minute with a tidal volume obtained from
a
nomogram. Arterial blood gases were measured and kept in the physiological
range
(SAOZ>90%, pH 7.30-7.45). Catheters were inserted into the femoral artery for
blood
pressure recording and blood gas measurement, and into both femoral veins for
drug
administration and venous sampling. Catheters were kept patent with
heparinized 0.9%
saline solution. Body temperature was maintained at 37-40°C with a
heating blanket.
The heart was exposed via a medial thoracotomy and a pericardial cradle
was created. Three bipolar stainless steel, TeflonTM-coated electrodes were
inserted into
the right atria for recording and stimulation, and one was inserted into the
left atrial
appendage for recording. A programmable stimulator (Digital Cardiovascular
Instruments, Berkeley, CA) was used to stimulate the right atrium with 2 ms,
twice
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diastolic threshold pulses. Two stainless steel, TeflonTM-coated electrodes
were inserted
into the left ventricle, one for recording and the other for stimulation. A
ventricular
demand pacemaker (GBM 5880, Medtronics, Minneapolis, MN) was used to stimulate
the ventricles at 90 beats/minute when (particular during vagal-AF) the
ventricular rate
became excessively slow. A P23 ID transducer, electrophysiological amplifier
(Bloom
Associates, Flying Hills, PA) and paper recorder (Astromed MT-95000, Toronto,
ON,
Canada) were used to record ECG leads II and III, atrial and ventricular
electrograms,
blood pressure and stimulation artefacts. The vagi were isolated in the neck,
doubly-
ligated and divided, and electrodes inserted in each nerve (see below). To
block
changes in (3-adrenergic effects on the heart, nadolol was administered as an
initial dose
of 0.5 mg/kg iv, followed by 0.25 mg/kg IV every two hours.
Atrial fibrillation model
Drug effects to terminate sustained AF maintained during continuous
vagal nerve stimulation were assessed. Unipolar hook electrodes (stainless
steel
insulated with TeflonTM, coated except for the distal 1-2 cm) were inserted
via a 21
gauge needle within and parallel to the shaft of each nerve. In most
experiments,
unipolar stimuli were applied with a stimulator (model DS-9F, Grass
Instruments,
Quincy, MA) set to deliver 0.1 ms square-wave pulses at 10 Hz and a voltage
60% of
that required to produce asystole. In some experiments, bipolar stimulation
was used.
The voltage required to produce asystole ranged between 3-20 volts. Under
control
conditions, a short burst of rapid atrial pacing (10 Hz, four times diastolic
threshold)
was delivered to induce AF which was ordinarily sustained for more than 20
minutes.
The vagal stimulation voltage was adjusted under control conditions, and then
readjusted after each treatment to maintain the same bradycardic effect. AF
was defined
as rapid (>500 minute under control conditions), irregular atrial rhythm with
varying
electrogram morphology.
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Measurement of electrophysiolo~ical variables and va a~ 1 response
Diastolic threshold current was determined at a basic cycle length of 300
ms by increasing the current 0.1 mA incrementally until stable capture was
obtained.
For subsequent protocols current was set to twice diastolic threshold. Atrial
and
ventricular ERP was measured with the extrastimulus method, over a range of S
1 S2
intervals at a basic cycle length of 300 ms. A premature extrastimulus S2 was
introduced every 15 basic stimuli. The S 1 S2 interval was increased in 5 ms
increments
until capture occurred, with the longest S 1 S2 interval consistently failing
to produce a
propagated response defining ERP. Diastolic threshold and ERP were determined
in
duplicate and averaged to give a single value. These values were generally
within 5 ms.
The interval between the stimulus artefact and the peak of the local
electrogram was
measured as an index of conduction velocity. AF cycle length (AFCL) was
measured
during vagal-AF by counting the number of cycles (number of beats -1) over a 2-
second
interval at each of the atrial recording sites. The three AFCLs measurements
were
averaged to obtain an overall mean AFCL for each experimental condition.
The stimulus voltage-heart rate relationship for vagal nerve stimulation
was determined under control conditions in most experiments. The vagal nerves
were
stimulated as described above with various voltages to determine the voltage
which
caused asystole (defined as a sinus pause greater than 3 seconds). The
response to vagal
nerve stimulation was confirmed under each experimental condition and the
voltage
adjusted to maintain the heart rate response to vagal nerve stimulation
constant. In
cases in which is was not possible to produce asystole, vagal nerve
stimulation was
adjusted to a voltage which allowed two 20-minute episodes of vagal-AF to be
maintained under control conditions (see below).
Experimentalprotocols
The experimental groups studied are summarized in Table 5. Each dog
received only one drug at doses indicated in Table 5. The first series of
experiments
were dose ranging studies, followed by blinded study in which 1-3 doses were
given.
All drugs were administered IV via an infusion pump, with drug solutions
prepared
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freshly in plastic containers on the day of the experiment. Vagal stimulation
parameters
were defined under control conditions as described above, and maintenance of
AF
during 20 minutes of vagal nerve stimulation under control conditions was
verified.
After the termination of AF, the diastolic threshold and ERP of the atrium and
ventricle
were determined. Subsequently, these variables were reassessed in the atrium
under
vagal nerve stimulation. Electrophysiological testing usually took 15-20
minutes. The
heart rate response to vagal nerve stimulation was confirmed and the vagal-
AF/electrophysiological testing protocol was repeated. A pre-drug blood sample
was
obtained and vagal-AF reinstituted. Five minutes later, one of the treatments
was
administered at doses shown in Table 5. The total dose was infused over 5
minutes and
a blood sample obtained immediately thereafter. No maintenance infusion was
given.
If AF terminated within 15 minutes, the electrophysiological measurements
obtained
under control conditions were repeated and a blood sample was obtained. If AF
was not
terminated by the first dose (within 15 minutes), a blood sample was obtained
and vagal
stimulation was discontinued to allow a return to sinus rhythm. The
electrophysiological measurements were repeated and a third and final blood
sample for
this dose was obtained. AF was reinitiated and the vagal-AF/drug
infusion/electrophysiological testing protocol was repeated until AF was
terminated by
the drug.
Statistical analysis
Group data are expressed as the mean ~ SEM. Statistical analysis was
carried out for effective doses for AFCL, and ERP using a t-test with a
Bonferroini
correction for multiple comparisons. Drug effects on blood pressure, heart
rate,
diastolic threshold and ECG intervals were assessed at the median dose for
termination
of AF. Two tailed tests were used and a p<0.05 was taken to indicate
statistical
significance.
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Tohla ~,
EXPERIMENTAL GROUPS AND DOSES OF DRUGS
Dose range Effective Mean dose Median dose
doses
Drug tested (p for terminatingrequired required
for for
mol/kg) AF (~mol/kg)termination termination
of of
AF (~mol/kg)AF (~mol/kg)
Flecainide 1.25-10 4-2.5; 1-10 4 2 2.5
A single drug was administered to each dog over the dose range
specified until AF was terminated. The number of dogs in which AF was
terminated at
each dose is shown (number of dogs-dose, in ~mol/kg). The mean ~ SEM as well
as
the median dose required to terminate AF is shown. Each dog received only one
drug.
A number of the compounds of the present invention have been
evaluated by this method. The results showed that all of the compounds tested
are
effective in terminating AF in the canine vagal-AF model. The conversion rates
are
similar to those reported for a variety of other class I and III drugs in this
model. The
effectiveness of flecainide as a control in the present study was comparable
to that
previously reported. All of the drugs prolonged AFCL prior to termination of
AF;
effects which are globally consistent with the wave length of re-entry model
for
termination of AF. The tested compounds of the present invention did not
reduce blood
pressure or heart rate at the median dose for termination of vagal-AF. The
heart rate
response to vagal nerve stimulation was similar in all groups and was not
influenced by
any of the compounds tested. Vagal nerve stimulation at 60% of the voltage
required to
produce asystole (10~1 V) produced a 1.3~0.1 second pause.
EXAMPLE 32
CANINE STERILE PERICARDITIS MODEL
This model has been used to characterize the mechanisms of AF and
atrial flutter (AFL). Waldo and colleagues have found that AF depends on
reentry and
CA 02268590 1999-04-12
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that the site of termination is usually an area of slowed conduction. This
canine model
is prepared by dusting the exposed atria with talcum powder followed by
"burst" pacing
the atria over a period of days after recovery. AF is inducible two days after
surgery,
however, by the fourth day after surgical preparation; sustainable atrial
flutter is the
predominant inducible rhythm. The inducibility of AF at day 2 is somewhat
variable,
such that only 50% of dogs may have sustained AF (generally <60 minutes) for a
requisite of 30 minutes. However, the sustainable atrial flutter that evolves
by the
fourth day is inducible in most preparations. Atrial flutter is more readily
"mapped" for
purposes of determining drug mechanisms. Inducibility of AF subsides after the
fourth
day post-surgery, similar to the AF that often develops following cardiac
surgery that
the sterile pericarditis model mimics. There may be an inflammatory component
involved in the etiology of post-surgery AF that would provide a degree of
selectivity to
an ischaemia or acid selective drug. Similarly, while coronary artery bypass
graft
(CABG) surgery is performed to alleviate ventricular ischaemia, such patients
may also
be at risk for mild atrial ischaemia due to coronary artery disease (CAD).
While atrial
infarcts are rare, there has been an association between AV nodal artery
stenosus and
risk for AF following CABG surgery. Surgical disruption of the autonomic
innervation
of the atria may also play a role in AF following CABG.
Methods
Studies were carried out in a canine model of sterile percarditis to
determine the potency and efficacy of Compound 1 in terminating atrial
fibrillation/flutter. Atrial flutter or fibrillation was induced 2 to 4 days
after creation of
sterile pericarditis in adult mongrel dogs weighing 19 kg to 25 kg. In all
instances, the
atrial fibrillation or flutter lasted longer than 10 minutes. All studies were
performed in
accordance with guidelines specified by our Institutional Animal Care and Use
Committee, the American Heart Association Policy on Research Animal Use, and
the
Public Health Service Policy on Use of Laboratory Animals.
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Creation of the Sterile Pericarditis Atrial FiblFlutter Model
The canine sterile pericarditis model was created as previously
described. At the time of surgery, a pair of stainless steel wire electrodes
coated with
FEP polymer except for the tip (O Flexon, Davis and Geck) were sutured on the
right
atrial appendage, Bachman's bundle and the posteroinferior left atrium close
to the
proximal portion of the coronary sinus. The distance between each electrode of
each
pair was approximately 5 mm. These wire electrodes were brought out through
the
chest wall and exteriorized posteriorly in the interscapular region for
subsequent use.
At the completion of surgery, the dogs were given antibiotics and analgesics
and then
were allowed to recover. Postoperative care included administration of
antibiotics and
analgesics.
In all dogs, beginning on postoperative day 2, induction of stable atrial
fibrillation/flutter was attempted in the conscious, non-sedated state to
confirm the
inducibility and the stability of atrial fib/flutter and to test the efficacy
of the drugs.
Atrial pacing was performed through the electrodes sutured during the initial
surgery.
On postoperative day 4, when stable atrial flutter was induced, the open-chest
study was
performed.
For the open-chest study, each dog was anesthetized with pentobarbital
(30 mg/kg IV) and mechanically ventilated with 100% oxygen by use of a Boyle
model
50 anesthesia machine (Harris-Lake, Inc.). The body temperature of each dog
was kept
within the normal physiological range throughout the study with a heating pad.
With
the dog anesthetized, but before the chest was opened, radiofrequency ablation
of the
His bundle was performed to create complete atrioventricular (AV) block by
standard
electrode catheter techniques. This was done to minimize the superimposition
of atrial
and ventricular complexes during subsequent recordings of unipolar atrial
electrograms
after induction of atrial flutter. After complete AV block was created, an
effective
ventricular rate was maintained by pacing of the ventricles at a rate of 60 to
80 beats per
minute with a Medtronic 5375 Pulse Generator (Medtronic Inc.) to deliver
stimuli via
the electrodes sutured to the right ventricle during the initial surgery.
CA 02268590 1999-04-12
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Determination of Stimulus Thresholds and Refractory Periods During Pacing
For the induction of AF/AFL, one of two previously described methods
was used: ( 1 ) introduction of one or two premature atrial beats after a
train of 8 paced
atrial beats at a cycle length of 400 ms, 300 ms, 200 ms, or 150 ms, or (2)
rapid atrial
Pacing for Periods of 1 to 10 seconds at rates incrementally faster by 10 to
50 beats per
minute than the spontaneous sinus rate until atrial flutter was induced or
there was a
loss of l:l atrial capture. Atrial pacing was performed from either the right
atrial
appendage electrodes or the posteroinferior left atrial electrodes. All pacing
was
performed using stimuli of twice threshold for each basic drive train with a
modified
Medtronic 5325 programmable, battery-powered stimulator with a pulse width of
1.8 ms.
After the induction of stable atrial fib/flutter (lasting longer than 10
minutes), the atrial fib/flutter cycle length was measured and the initial
mapping and
analysis were performed to determine the location of the atrial fib/flutter
reentrant
circuit. Atrial flutter was defined as a rapid atrial rhythm (rate, >240 beats
per minute)
characterized by a constant beat-to-beat cycle length, polarity, morphology,
and
amplitude of the recorded bipolar electrograms.
Drug Efficacy Testing Protocol
1. Effective refractory periods (ERPs) were measured from three
sites: right atrial appendage (RAA), posterior left atrium (PLA), and
Bachman's
Bundle (BB), at two basic cycle lengths 200 and 400 ms.
2. Pace induce A-Fib or AFL. This was attempted for one hour. If
no arrhythmia was induced, no further study was done on that day.
3. If induced, AF must have been sustained for 10 minutes. Then a
waiting period was allowed for spontaneous termination or 20 minutes,
whichever came first.
4. AF was then reinduced and 5 minutes was allowed before starting
drug infusion.
5. Drug was then infused in a bolus over 5 minutes.
CA 02268590 1999-04-12
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6. If AF terminated with the first dose then a blood sample was
taken and ERP measurements were repeated.
7. Five minutes was allowed for the drug to terminate. If there was
no termination then the second dose was given over 5 minutes.
8. After termination and ERPs were measured, a second attempt to
reinduce AF was tried for a period of ten minutes.
9. If reinduced and sustained for 10 minutes, a blood sample was
taken and the study repeated from #3 above.
10. If no reinduction, then the study was over.
A number of the compounds of the present invention have been
evaluated by this method. The results showed that all of the compounds tested
are
effective in terminating episodes of atrial fibrillation/flutter in this
model. There was no
proarrhythmia or cardiovascular adverse events observed during drug treatment.
EXAMPLE 33
IN VITRO ASSESSMENT OF INHIBITION ACTIVITY OF ION CHANNEL
MODULATING COMPOUNDS ON DIFFERENT CARDIAC ION CURRENTS
Cell culture:
The relevant cloned cardiac ion channels (e.g. Kvl.4, Kvl.S, Kv4.2,
Kv2.1 etc.) were studied by transient transfection into HEK cells using the
mammalian
expression vector pCDNA3. Transfections for each channel type were carried out
separately to allow individual study of the ion channel of interest. Cells
expressing
channel protein were detected by cotransfecting cells with the vector pHook-1
(Invitrogen, San Diego, CA, USA). This plasmid encoded the production of an
antibody to the hapten phOX, which when expressed is displayed on the cell
surface.
Equal concentrations of individual channel and pHook DNA were incubated with
lOx
concentration of lipofectAce in Modified Eagle's Medium (MEM, Canadian Life
CA 02268590 1999-04-12
113
Technologies) and incubated with parent HEK cells plated on 25 mm culture
dishes.
After 3-4 hours the solution was replaced with a standard culture medium plus
20%
fetal bovine serum and 1% antimycotic. Transfected cells were maintained in at
37C in
an air/5%C02 incubator in 25 mm Petri dishes plated on glass coverslips for 24-
48
hours to allow channel expression to occur. 20 min prior to experiments, cells
were
treated with beads coated with phOX. After 15 min, excess beads were washed
off with
cell culture medium and cells which had beads stuck to them were used for
electrophysiological tests.
Solutions:
For whole-cell recording the control pipette filling solution contained (in
mM): KCI, 130; EGTA, 5; MgCI2, 1; HEPES, 10; Na2ATP, 4; GTP, 0.1; and was
adjusted to pH 7.2 with KOH. The control bath solution contained (in mM):
NaCI, 135;
KCI, 5; sodium acetate, 2.8; MgCl2, 1; HEPES, 10; CaCl2, 1; and was adjusted
to pH
7.4 with NaOH. A low pH bath solution contained the same constituents as
control
bath, but pH was adjusted to 6.4 using NaOH. All chemicals were from Sigma
Chemical Co. (St-Louis, MO). The test ion channel modulating compound was
dissolved to lOmM stock solutions in water and used at concentrations between
0.5 and
100uM. All compounds were protected from the light during all experiments.
Electrophysiological procedures:
Coverslips containing cells were removed from the incubator before
experiments and placed in a superfusion chamber (volume 250 ~1) containing the
control bath solution at 22C to 23C. All recordings were made via the
variations of the
patch-clamp technique, using an Axopatch 200A amplifier (Axon Instruments,
CA).
Patch electrodes were pulled from thin-walled borosilicate glass (World
Precision
Instruments; FL) on a horizontal micropipette puller, fire-polished, and
filled with
appropriate solutions. Electrodes had resistances of 1.0-2.5 pohm when filled
with
control filling solution. Analog capacity compensation was used in all whole
cell
measurements. In some experiments, leak subtraction was applied to data.
Membrane
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potentials have not been corrected for any functional potentials that arose
between the
pipette and bath solution. Data were filtered at 5 to 10 kHz before
digitization and
stored on a microcomputer for later analysis using the pClamp6 software (Axon
Instruments, Foster City, CA). Due to the high level of expression of channel
cDNA's
in HEK cells, there was no need for signal averaging. The average cell
capacitance was
quite small, and the absence of ionic current at negative membrane potentials
allowed
faithful leak subtraction of data.
Data analysis:
The concentration-response curves for changes in peak and steady-state
current produced by the test compound were computer-fitted to the Hill
equation:
f--1-1/[1+(IC50[D])"] [1]
where f is the fractional current (f--Idrug/Icontrol) at drug concentration
[D]; IC50 is the concentration producing half maximal inhibition and n is the
Hill
coefficient. The rapid component of inactivation induced by the test compound
was
much faster than that observed in the absence of drug. Therefore, we used this
drug
induced time-constant ('tb,ock) as an approximation of the drug channel
interaction
kinetics, according to the equation:
1 /ib,o~k = k+, [D]+ k_, [2a]
and Kd=k_,/ k+, [2b]
in which 'Lb,"ck 1S the current decay time constant caused by the drug; [D]
is the concentration of drug; k+, and k_, are the apparent rate constants of
binding and
unbinding for the drug, respectively. The voltage dependence of block for the
uncharged drug was determined as follows: leak-corrected current in the
presence of
drug was normalized to matching control at each voltage above -20 mV. Using
data
points in the range of full channel opening ( > +20 mV), we have calculated
the
fractional block (f--Idrug/Icontrol) at each potential and fitted data to the
Woodhull
equation:
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f--[D]/([D]+Kd*.e q~~T) [3]
where f, R, z and T have their usual meanings, q represents the fractional
electrical distance, i.e., the fraction of the transmembrane electrical field
sensed by a
single charge at the receptor site. Kd* represents the binding affinity at the
reference
voltage (0 mV). Experimental values are given as means ~ S.E. or S.D. as
stated.
A number of the compounds of the present invention have been
evaluated by this method. The results showed that the compounds of the present
invention tested are effective in blocking the various cardiac ion channels.
There are
different dose responses in the activity to block the various cardiac currents
for the
different compounds tested.
EXAMPLE 34
ASSESSMENT OF PROARRHYTHMIA (TORSADE DE POINTES) RISK OF ION CHANNEL
1 S MODULATING COMPOUNDS IN PRIMATES
These experiments were carried out in Bogor, Indonesia. Experimental
protocols and procedures were approved by the ethics review committee at
Lembaga
Penelitial Institut Pertainian Bogor, Indonesia.
Methods
General surgical preparation:
All studies were carried out in male Macaca fascicularis weighing
between 4 and 5.5 kg. Animals were fasted over night and pre-medicated with
ketamine (10 mg/kg im). Both saphenous veins were cannulated and a saline drip
instituted to keep the lines patent. Halothane anaesthesia (1.5% in oxygen)
was
administered via a face mask. Lidocaine spray (10% spray) was used to
facilitate
intubation. After achieving a sufficient depth of anaesthesia, animals were
intubated
with a 4 or 5 French endotrachial tube. After intubation halothane was
administered via
the endotracheal tube and the concentration was reduced to 0.75-1%. Artificial
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respiration was not used and all animals continued to breathe spontaneously
throughout
the experiment. Blood gas concentrations and blood pH were measured using a
blood
gas analyser (AVO OPTI I). The femoral artery was cannulated to record blood
pressure.
Blood pressure and a modified lead II ECG were recorded using a
MACLAB 4S recording system paired with a Macintosh PowerBook (2400c/180). A
sampling rate of 1 kHz was used for both signals and all data was archived to
a Jazz
disc for subsequent analysis.
Vagal nerve stimulation:
Either of the vagi was isolated by blunt dissection and a pair of
electrodes inserted into the nerve trunk. The proximal end of the nerve was
crushed
using a vascular clamp and the nerve was stimulated using square wave pulses
at a
frequency of 20 Hz with a 1 ms pulse width delivered from the MACLAB
stimulator.
The voltage (range 2-lOV) was adjusted to give the desired bradycardic
response. The
target bradycardic response was a reduction in heart rate by half. In cases
where a
sufficient bradycardic response could not be obtained, 10 ~g/kg neostigmine iv
was
administered. This dose of neostigmine was also given after administration of
the test
drug in cases where the test drug had vagolytic actions.
Test Compounds:
The test compounds were transported to Bogor, Indonesia on dry ice. A
near maximum tolerated bolus dose of the test compound, infused (iv) over 1
minute,
was used to assess the risk of torsade de pointes caused by each ion channel
modulating
compound. The actual doses varied slightly depending on the animals weight.
Clofilium, 30 ~mol/kg, was used as a positive comparison (control) for these
studies.
The expectation was that a high dose of drug would result in a high incidence
of
arrhythmias. The test compounds were dissolved in saline immediately before
administration.
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The necessity of vagal nerve stimulation for the model was assessed by
administering 2 mg/kg clofilium iv without stimulating the vagal nerve.
Animals
included in this experiment had previously received the same test compound 2-5
days
prior to the experiment.
Experimental protocol:
Each animal received a single dose of a given drug iv. Before starting
the experiment two, 30 second episodes of vagal nerve stimulation were
recorded. A
five minute rest period was allowed between episodes and before starting the
experiment. The test solution was administered as an iv bolus at a rate of 5
ml/minute
for 1 minute using an infusion pump (total volume 5 ml). ECG and blood
pressure
responses were monitored continuously for 60 minutes and the occurrence of
arrhythmias was noted. The vagal nerve was stimulated for 30 seconds at the
following
times after injection of the drug: 30 seconds, 2, 5, 10, 15, 20, 25, 30 and 60
minutes.
Blood samples (1 ml total volume) were taken from each treated animal
at the following times after drug administration: 30 seconds, 5, 10, 20, 30
and 60
minutes as well as 3, 6, 24 and 48 hours. Blood samples taken up to 60 minutes
after
drug administration were arterial while those taken after this time were
venous.
Samples were centrifuged, the plasma decanted and frozen. Samples were kept
frozen
before analysis of plasma concentration of the drug and potassium.
Statistics:
The effect of drugs on blood pressure, heart rate and ECG intervals are
described as the mean~SEM for a group size of "n."
A number of the compounds of the present invention have been
evaluated by this method. No proarrhythmia or cardiovascular adverse events
were
detected.
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EXAMPLE 35
ASSESSMENT OF PAIN BLOCKAGE
Guinea pigs were shaved (backs only) and 6 aliquots (50 ~l) of
compound solution (10 mg/ml) were injected just beneath the skin to form 6
blebs
which were outlined with a permanent marker. Pain responses were assessed as
above
on each bleb at regular intervals up to 4 hours post injection and the
duration of pain
blockage was recorded for three animals for each test solution.
Table 7
Compound Dm'ation of
Blockage (hours)
1 2.5
2 3
3 2.5
11 3
S aline 0
All publications and patent applications mentioned in this specification
are herein incorporated by reference to the same extent as if each individual
publication
or patent application was specifically and individually incorporated by
reference.
From the foregoing it will be appreciated that, although specific
embodiments of the invention have been described herein for purposes of
illustration,
various modifications may be made without deviating from the spirit and scope
of the
invention. Accordingly, the invention is not limited except as by the appended
claims.
