Note: Descriptions are shown in the official language in which they were submitted.
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W O 96~9140 ' PCT~US96/08672
TITLE OF THE INVENTION
ALPHA la ADRENERGIC RECEPTOR ANTAGONISTS
~l~LD OF THE INVENTION:
This application is a continuation-in-part of copending
application U.S. Serial No. 0~/470,164, filed June 6, 1995, the contents
of which are hereby incorporated by reference.
This invention relates to certain novel compounds and
derivatives thereof, their synthesis, and their use as selective alpha-l a
adrenoceptor antagonists. More particularly, the compounds of the
present invention are useful for treating benign prostatic hyperplasia
(BPH).
BACKGROUND OF THE INVENTION
Human adrenergic receptors are integral membrane
proteins which have been classified into two broad classes, the alpha and
the beta adrenergic receptors. Both types mediate the action of the
peripheral sympathetic nervous system upon binding of catecholamines,
norepinephrine and epinephrine.
Norepinephrine is produced by adrenergic nerve endings,
while epinephrine is produced by the adrenal medulla. The binding
affinity of adrenergic receptors for these compounds forms one basis of
the classification: alpha receptor~ bind norepinephrine more strongly
than epinephrine and much more strongly than the synthetic compound
isoproterenol. The binding affinity of these horrnones is reversed for
the beta receptors. In many tissues, the functional responses, such as
smooth muscle contraction, induced by alpha receptor activation are
opposed to responses induced by beta receptor binding.
Subsequently, the functional distinction between alpha and
~ 30 beta receptors was further highlighted and refined by the
pharmacological characterization of these receptors from various
~ ~nim~l and tissue sources. As a result, alpha and beta adrenergicreceptors were further subdivided into al, a2, 1~l, and ~2 subtypes.
Functional differences between al and a2 receptors have been
CA 02221842 1997-11-18
W O 96~9140 - PCT/U' ~ G72
recognized, and compounds which exhibit selective binding between
these two subtypes have been developed. Thus, in WO 92/0073, the
selective ability of the R(+) enantiomer of terazosin to selectively bind
to adrenergic receptors of the alpha 1 subtype was reported. The alla2
5 selectivity of this compound was disclosed as being significant because
agonist stim~ tion of the a2 receptors was said to inhibit secretion of
epinephrine and norepinephrine, while antagonism of the a2 receptor
was said to increase secretion of these horrnones. Thus, the use of non-
selective alpha-adrenergic blockers, such as phenoxyben7~mine and
10 phentol~mine, is limited by their a2 adrenergic receptor mediated
induction of increased plasma catecholarnine concentration and the
attendant physiological sequelae (increased heart rate and smooth muscle
contraction).
For a general background on the a-adrenergic receptors,
15 the reader's attention is directed to Robert R. Ruffolo, Jr., a-
Adrenoreceptors: Molecular Biolo~y. Biochemistry and Pharmacolo~y.
(Pro~ress in Basic and Clinical Pharmacolo~y series, Karger, 1991),
wherein the basis of al/a2 subclassification, the molecular biology,
signal transduction (G-protein interaction and location of the significant
20 site for this and ligand binding activity away from the 3'-terminus of
alpha adrenergic receptors), agonist structure-activity relationships,
receptor functions, and therapeutic applications for compounds
exhibiting a-adrenergic receptor affinity was explored.
The cloning, sequencing and expression of alpha receptor
25 subtypes from ~nim~l tissues has led to the subclassification of the al
receptors into ~cla, (Lomasney, et al., J. Biol. Chem.. 266:6365-6369
(1991), rat ala; Bruno et al., BBRC, 179:1485-1490 (1991), hllm~n
ala)~ a1b (Cotecchia, et al., PNAS. ~5;7159-7163 (1988), hamster alb;
Libert, et al., Science, (19~9), dog alb; Ramarao, et al., J. ~iol.
Chem., 267:21936-21945 (1992), hllm~3n alb)~ and most recently, in a
study using bovine brain, a new alC subtype was proposed (Schwinn, et
al.. J. Biol. Chem.. 265:~1~3-~ S9 (1990); Hirasawa et al., BBRC
195:902-909 (1993), described the cloning, functional e~cpression and
tissue distribution of a human alc adrenergic receptor; Hoehe et al.,
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Human Mol. Genetics 1(5):349 (~/92) noted the existence of a two-allele
Pstl restriction fragment polymorphism in the alC adrenergic receptor
gene; another study suggests that there may even be an alpha-ld
receptor subtype, see Perez et al., Mol. Pharm., 40:876-883, 1992).
S Each al receptor subtype exhibits its own pharmacologic and tissue
specificities. Schwinn and coworkers noted that the cloned bovine al c
receptor exhibited pharmacological properties proposed for the ala
subtype. Nonetheless, based on its non-expression in tissues where the
ala subtype is expressed, and its sensitivity to chloroethylclonidine, the
receptor was given a new designation.
The differences in the a-adrenergic receptor subtypes have
relevance in pathophysiologic conditions. Benign prostatic hyperplasia,
also known as benign prostatic hypertrophy or BPH, is an illness
typically affecting men over fifty years of age, increasing in severity
lS with increasing age. The symptoms of the condition include, but are not
limited to, increased difficulty in urination and sexual dysfunction.
These symptoms are induced by enlargement, or hyperplasia, of the
prostate gland. As the prostate increases in size, it impinges on free-
flow of fluids through the male urethra. Concommitantly, the increased
noradrenergic innervation of the enlarged prostate leads to an increased
adrenergic tone of the bladder neck and urethra, further restricting the
flow of urine through the urethra.
In benign prostatic hyperplasia, the male hormone Sa-
dihydrotestosterone has been identified as the principal culprit. The
continual production of Sa-dihydrotestosterone by the male testes
induces incremental growth of the prostate gland throughout the life of
the male. Beyond the age of about fifty years, in many men, this
enlarged gland begins to obstruct the urethra with the pathologic
symptoms noted above.
The elucidation of the mech~ni.~m sllmm~rized above has
resulted in the recent development of effective agents to control, and in
many cases reverse, the pernicious advance of BPH. In the forefront of
these agents is Merck & Co., Inc.s' product PROSCAR(~) (finasteride).
The effect of this compound is to inhibit the enzyme testosterone S-
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alpha reductase, which converts testosterone into Sa-dihydrotesterone,
resulting in a reduced rate of prostatic enlargement, and often reduction
in prostatic mass.
The development of such agents as PROSCAR(~ bodes well
S for the long-term control of BPH. However, as may be appreciated
from the lengthy development of the syndrome, its reversal also is not
immediate. In the interim, those males suffering with BPH continue to
suffer, and may in fact lose hope that the agents are working sufficiently
rapidly.
In response to this problem, one solution is to identify
pharmaceutically active compounds which complement slower-acting
therapeutics by providing acute relief. Agents which induce relaxation
of the urethral smooth muscle, by binding to alpha-l adrenergic
receptors, thus reducing the increased adrenergic tone due to the
disease, would be good candidates for this activity. Thus, one such
agent is alfuzosin, which is reported in EP 0 204597 to induce urination
in cases of prostatic hyperplasia. Likewise, in WO 92/0073, the
selective ability of the R(+) enantiomer of terazosin to bind to
adrenergic receptors of the ocl subtype was reported. In addition, in
WO 92/161213, hereby incorporated by reference, combinations of ~-
alpha-reductase inhibitory compounds and alphal-adrenergic receptor
blockers (terazosin, doxazosin, prazosin, bunazosin, indoramin,
alfuzosin) were disclosed. However, no information as to the CXla~ alb,
or alC subtype specificity of these compounds was provided as this data
and its relevancy to the treatrnent of BPH was not known. Current
therapy for BPH uses existing non-selective alpha-l antagonists such as
prazosin (Minipress, Pfizer), terazosin (Hytrin, Abbott) or doxazosin
mesylate (Cardura, Pfizer). These non-selective antagonists suffer from
side effects related to antagonism of the alpha-la and alpha-lb receptors
in the peripheral vasculature, e.g., orthostatic hypotension and syncope.
Typically, identification of active compounds is
accomplished through use of ~nim~l tissues known to be enriched in
adrenergic receptors. Thus, rat tissues have been used to screen for
potential adrenergic receptor antagonists. However, because of species
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WO 96/39140 - PCT/U', 5,'~ 5 ~72
variability, compounds which appear active in animal tissue may not be
active or sufficiently selective in humans. This results in subst~nti~l
wastage of time and effort, particularly where high volume compound
screening programs are employed. There is also the danger that
S compounds, which might be highly effective in humans, would be
missed because of their absence of appreciable affinity for the
heterologous ~nim~l receptors. In this regard, it has been noted that
even single amino acid changes between the sequence of biologically
active proteins in one species may give rise to substantial
pharmacological differences. Thus, Fong et al., (J. Biol. Chem
267:2566~S-25671, 1992) showed that there are 22 divergent amino acid
residues between the sequence of the human neurokinin-l receptor and
the homologous rat receptor. They further showed, in studies with
mutant receptors, that substitution of only two amino acid residues was
1~ both necessary and sufficient to reproduce the rat receptor's antagonist
binding affinity in the human receptor. Oksenberg et al., (Nature~
360:161-163, 1992) showed that a single amino-acid difference confers
major pharmacological variation between the human and the rodent 5-
hydroxytrypt~min~ receptors. Likewise, Kuhse et al., (Neuron. 5:867-
873, 1990) showed that a single amino-acid exchange alters the
pharmacology of the neonatal rat glycine receptor subunit. This
difficulty and unpredictability has resulted in a need for a compound
screen which will identify compounds that will be active in hllm~n~.
These problems were solved by cloning the hllm~n
adrenergic receptor of the al C subtype (ATCC CRL 11140) and the use
of a screening assay which enables identification of compounds which
specifically interact with the hllm~n alc adrenergic receptor. [PCT
International Application Publication Nos. W094/08040, published 14
April 1994 and WO94/10989, published 26 May 1994] As disclosed in
the instant patent disclosure, a cloned human alC adrenergic receptor
and a method f~r identifying compounds which bind the human alC
receptor has now made possible the identification of selective human
a1C adrenergic receptor antagonists useful for treating BPH. The
instant patent disclosure discloses novel compounds which selectively
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W O 96~9140 ~ PCT/U'~ fi672
-- 6 --
bind to the hllm~n alC receptor. These compounds are further tested
for binding to other human alpha 1 receptor subtypes, as well as
counterscreened against other types of receptors, thus defining the
specificity of the compounds of the present invention for the human
5 alC adrenergic receptor.
Compounds of this invention are used to reduce the acute
symptoms of BPH. Thus, compounds of this invention may be used
alone or in conjunction with a more long-term anti-BPH therapeutics,
such as testosterone 5-alpha reductase inhibitors, including PROSCAR(~
10 (finasteride). Aside from their utility as anti-BPH agents, these
compounds may be used to induce highly tissue-specific, localized alc
adrenergic receptor blockade whenever this is desired. Effects of this
blockade include reduction of intra-ocular pressure, control of cardiac
arrhythmias, and possibly a host of alpha-lc receptor mediated central
15 nervous system events.
NOMENCLATURE
Recently, a new al adrenergic receptor (al-AR)
classification scheme similar to that proposed by Ford, et al. [al-
20 Adrenoceptor Classification: Sharpenin~ Occam's Razor~ Trends inPharm. Sci. 1994, 15, 167-170] was adopted at the August, 1994
meeting of the International Union of Pharmacology (IUPHAR) in
Montreal, Canada. The al-AR genes formerly known as ala/d~ alb
and alC were renamed ald, alb and ala, respectively. This new
25 naming system reflects the correspondence between the proteins
encoded by the ala and alb genes (new IllPHAR nomenclature) and
the receptors characterized by traditional pharmacological means as
alA and alg~ respectively, in the literature. Recombinant receptors
and receptors characterized pharmacologically in tissues are
30 distinguished by lowercase and uppercase subscripts, respectively.
The above discussion contained in the Background section
used the former classification scheme (i.e., alald~ alb and a1c);
however, hereinafter, the new classification scheme will be utilized (i.e.,
a1d, alb and ala). Thus, what was formerly referred to as the alC
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W O 96~9140 - PCTAUS96/08672
receptor (and a1C receptor antagonists) will hereinafter be referred to
lltili7.ing the new nomenclature as the ala receptor (and a1a receptor
antagonists).
S SUMMARY OF THE ~VENTION
The present invention provides a method of treating a
disease which is susceptible to treatment by antagonism of the alpha 1 a
receptor which comprises ~lmini~tering to a subject in need thereof a
therapeutically effective amount of a compound of the formula I
4R R~
( R)q ~ ~13
wherein
R l is independently selected from hydrogen, Cl 4 aLkyl, R2(CH2)n- or
unsubstituted, mono-, di- or tri-substituted phenyl wherein the
15 substituents on the phenyl are independently selected from halogen,
nitro, amino, Cl 4 alkyl, Cl 4 alkoxy, furanyl, pyridyl, thienyl or aryl;
R2 is selected from cyano-, NH2CO-, (R3)2NCo-, R3CONMe-,
R12(CH2)p-OC(O)NH-, R3(CH2)mC(o)pNH-~ R3CONMe-,
20 R3S(o)mNH- or het;
R3 is selected from hydrogen, C1 4 alkyl, het or aryl;
R4 and R5 taken together are =O; or
R4 is hydrogen, and RS is selected from hydrogen or hydroxy;
R6 is selected from unsubstituted, mono-, di- or tri-substituted phenyl
wherein the substituents on the phenyl are independently selected from
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halogen, nitro, amino, Cl 4 alkyl, Cl 4 alkoxy or aryl; naphthyl;
thi~n~phthenyl; benzofuranyl; indolyl; 2-substituted indolyl where ~e
substitutent is halogen, Cl 4 alkyl, Cl 4 alkoxy or aryl;
2,5-disubstituted indolyl where the substituents are independently
S selected from hydrogen, halogen, nitro, amino, Cl 4 aLkyl, Cl 4 aLkoxy
or aryl; or
-Z~
R1~ R14;
R13 is selected from hydrogen or Cl 4 aLkyl;
10 R14 is selected from hydrogen or COCH3;
Rl5 is selected from hydrogen, NO2 or CN;
Z is selected from C=O or CH2;
1:~
aryl is unsubstituted, mono-, di- or tri-substituted phenyl wherein the
substituent~s on the phenyl are independently selected from halogen,
nitro~ amino, Cl 4 alkyl, Cl 4 alkoxy, pyridyl, thienyl or furanyl;
20 het is selected from
~ N--N/ N~/ ,0~ _ ,N,
O--N N-NH ~NMe
H ~ ~ N HN~N~>-- H2N N
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W O 96~9140 - PCT/U',~ 672
N~ ¢~~ H2Nl'N~ or ¢~ CO2Me
m is an integer of from zero to two;
n is an integer of from zero to four; and
p is an integer of from one to two;
S q is an integer of from one to four;
and the pharmaceutically acceptable salts thereof.
Preferably, the compounds utilized in the methods of the
present invention have the formula
4R R5
(1 R qt~
~(CH2)n R6
1 0 wherein
R6 is selected from unsubstituted, mono-, di- or tri-substituted phenyl
wherein the substituents on the phenyl are independently selected from
halogen, nitro, amino, C1 4 alkyl, Cl 4 alkoxy or aryl; naphthyl;
thi~n~phthenyl; benzofuranyl; indolyl; 2-substituted indolyl where the
substitutent is halogen, Cl 4 alkyl, Cl 4 alkoxy or aryl; or 2,5-
disubstituted indolyl where the substituents are independently selected
from hydrogen, halogen, nitro, amino, Cl 4 alkyl, Cl 4 alkoxy or aryl;
wherein all other variables are as defined above;
or a pharmaceutically acceptable salt thereof.
More preferably, the compounds utilized in the methods of
the present invention have the formula
1 R~ ~ (C H~)n R5
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W O 96~9140 PCT~US96/08672
- 10 -
wherein each Rl is independently selected from hydrogen, R2(CH2)n-
or unsubstituted, mono-, di- or tri-subsLiLuLed phenyl wherein the
substituents on the phenyl are independently selected from halogen,
nitro, amino, Cl 4 aL~yl, Cl 4 aL~oxy, furanyl, pyridyl, thienyl or aryl;
S wherein all other variables are as defined above;
or a pharmaceutically acceptable salt ~ereof.
Examples of diseases which are susceptible to treatment by
antagonism of the alpha la receptor include, but are not limited to,
BPH, high intraocular pressure, high cholesterol, impotency,
sympathetically mediated pain and cardiac arrhythmia.
In one embodiment of the present invention is a method of
treating benign prostatic hyperplasia in a subject in need thereof which
comprises a-lmini~tering to the subject a therapeutically effective
amount of the compound of formula I described above. In a second
embodiment of the present invention is a method of inhibiting
contraction of prostate tissue in a subject in need thereof which
comprises a-lministering to the subject a therapeutically effective
amount of the compound of formula I described above. In a third
embodiment of the present invention is a method of relaxing urethral
smooth muscle in a subject in need thereof which comprises
a-lmini.~tering to the subject a therapeutically effective amount of the
compound of formula I described above. In preferred embodiments of
the present invention, the compound additionally does not cause a fall in
blood pressure when ~lmini.~tered for treating BPH, inhibiting
contraction of prostate tissue or relacing urethral smooth muscle.
In a class of the invention are any of the methods described
above wherein the compound is ~3(1ministered in combination with a
testosterone 5-alpha reductase inhibitor. Preferably, the testosterone 5-
alpha reductase inhibitor is finasteride.
More particularly illustrating the invention is a compound
of the formula:
-
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W O 96~9140
PCT~US96/0867Z
~ ~ ~ (T H)n R~
wherein
R9 is selected from hydrogen, C1 4 alkyl, R2(CH2)n- or unsubstituted,
S mono-, di- or tri-substituted phenyl wherein the substituents on the
phenyl are independently selected from halogen, nitro, amino,
Cl 4 alkyl, Cl 4 aL~oxy, furanyl, pyridyl, thienyl or aryl;
R2 is selected from NC-, NH2CO-, (R3)2NCo-, R3CoNH-,
10 R3CONMe-, R3-S(o)mNH- or het;
R3 is selected from hydrogen, Cl 4 alkyl, het or aryl;
R4 and R5 taken together are =O; or
R4 is hydrogen and R5 is hydrogen or hydroxy;
R6 is selected from unsubstituted, mono-, di- or tri-substituted phenyl
wherein the substituents on the phenyl are independently selected from
20 halogen, nitro, amino, Cl 4 alkyl, Cl 4 alkoxy or aryl; naphthyl;
thi~n~rhthenyl; benzofuranyl; indolyl; 2-substituted indolyl where the
substitutent is selected from halogen, Cl 4 aLkyl, Cl 4 alkoxy or aryl;
2,5-disubstituted indolyl where the substituents are independently
selected from hydrogen, halogen, nitro, amino, Cl 4 alkyl, Cl 4 alkoxy
25 or aryl; or
_ Z ~
~N
1 4
:::
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W O 96~9140 PCTrUS96/08672
R~ is selected from hydrogen, Cl 4 aLkyl, Rl l(CH2)n- or unsubstituted,
mono-, di- or tri-substituted phenyl wherein the substituents on the
phenyl are independently selected from halogen, nitro, amino,
5 Cl 4 alkyl, Cl A alkoxy, furanyl, pyridyl, thienyl or aryl;
Rl 1 is selected from cyano, R12-S(O)mNH-, R12CONMe-,
R 1 2(CH2)p-OC(O)NH-, R 1 2(CH2)pC(O)NH- or het,
10 R12 is selected from hydrogen, het or unsubstituted, mono-, di- or tri-
substituted phenyl wherein the substituents on the phenyl are
independently selected from halogen, nitro, amino, Cl 4 alkyl or
Cl 4 aLkoxy;
15 R13 is selected from hydrogen or Cl 4 alkyl;
R14 is selected from hydrogen or COCH3;
R15 is selected from hydrogen, NO2 or CN;
Z is selected from C=O or CH2;
aryl is unsubstituted, mono-, di- or tri-substituted phenyl wherein the
substituents on the phenyl are independently selected from halogen,
25 nitro, amino, Cl 4 aLkyl, Cl 4 alkoxy, pyridyl, thienyl or furanyl;
het is selected from
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W O 96~9140 - PCT~US96/08672
~,> ~N~ </ ~ N~ N'N~
0~ N~ ~- N~ ~ NMe ~
N~ 3\ H2N--~'N~ or ~CO M
m is an integer of from zero to two;
n is an integer of from zero to four; and
p is an integer of from one to two;
provided that R~ and R9 are not sirnultaneously hydrogen; and
provided further that when R9 is hydrogen, and R8 is
-(CH2)r~N,~
where n is zero or one, then R6 is selected from mono-,
lO di- or tri-substituted phenyl wherein the substituents on the phenyl are
independently selected from halogen, nitro, amino, Cl 4 aLkyl,
Cl 4 alkoxy or aryl; naphthyl; ~hi~n~phthenyl; benzofuranyl; indolyl;
2-substituted indolyl where the substitutent is halogen, Cl 4 alkyl,
Cl 4 alkoxy or aryl; or 2,5-disubstituted indolyl where the substituents
lS are independently selected from hydrogen, halogen, nitro, amino,
Cl 4 alkyl, Cl 4 alkoxy or aryl; or
-Z'~C?
~ R15 R14; and
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- 14 -
provided further that when R9 is hydrogen, R~ is cyano, and n is two,
then R6 is selected from mono-, di- or tri-substituted phenyl wherein
the substituents on the phenyl are independently selected from halogen,
nitro, amino, Cl 4 alkyl, Cl 4 alkoxy or aryl; naphthyl; thi~n~phthenyl;
5 benzofuranyl; indolyl; 2-substituted indolyl where the substitutent is
halogen, Cl 4 alkyl, C1 4 alkoxy or aryl; or 2,5-disubstituted indolyl
where the substituents are independently selected from hydrogen,
halogen, nitro, amino, Cl 4 aLkyl, Cl 4 alkoxy or aryl; or
-Z'¢~c?
R15 R14;
10 and the pharmaceutically acceptable salts thereof.
Preferably, the compound is of the formula
9R~ ~ (C H2)n R6
wherein
R6 is selected from unsubstituted, mono-, di- or tri-substituted phenyl
15 wherein the substituents on the phenyl are independently selected from
halogen, nitro, amino, Cl 4 alkyl, Cl 4 alkoxy or aryl; naphthyl;
thi~n~phthenyl; benzofuranyl; indolyl; 2-substituted indolyl where the
substitutent is halogen, Cl 4 aLkyl, Cl 4 alkoxy or aryl; or
2,5-disubstituted indolyl where the substituents are independently
20 selected from hydrogen, halogen, nitro, amino, Cl 4 aLkyl, Cl 4 alkoxy
or aryl; and all other variables are as de~med above;
provided that R~ and R9 are not simultaneously hydrogen; and
25 provided further that when R9 is hydrogen, and Rg is
CA 02221842 1997-11-18
W O 96~9140 PCT/U',~'.8~72
- 15-
~(CH2)r~N~ where n is zero or one, then R6 is selected from mono-,
di- or tri-substituted phenyl wherein the substituents on the phenyl are
independently selected from halogen, nitro, amino, Cl 4 alkyl,
Cl 4 alkoxy or aryl; naphthyl; thi~n~phthenyl; benzofuranyl; indolyl;
2-substituted indolyl where the substitutent is halogen, Cl 4 alkyl,
Cl 4 alkoxy or aryl; or 2,5-disubstituted indolyl where the substituents
are independently selected from hydrogen, halogen, nitro, amino,
Cl 4 aLkyl, Cl 4 alkoxy or aryl; and
provided further that when R9 is hydrogen, R~ is cyano, and n is two,
then R6 is selected from mono-, di- or tri-substituted phenyl wherein
the substituents on the phenyl are independently selected from halogen,
nitro, amino, Cl 4 alkyl, Cl 4 aLkoxy or aryl; naphthyl; thianaphthenyl;
benzofuranyl; indolyl; 2-substituted indolyl where the substitutent is
halogen, Cl 4 alkyl, Cl 4 alkoxy or aryl; or 2,5-disubstituted indolyl
where the substituents are independently selected from hydrogen,
halogen, nitro, amino, Cl 4 aL~yl, Cl 4 aL~coxy or aryl;
and the pharmaceutically acceptable salts thereof.
Illustrative of the invention is the compound wherein
R~ is selected from hydrogen, Rl l(CH2)n- or unsubstituted, mono-, di-
or tri-substituted phenyl wherein the substituents on the phenyl are
independently selected from halogen, nitro, amino, Cl 4 alkyl,
Cl 4 alkoxy, furanyl, pyridyl, thienyl or aryl; and
R9 is selected from hydrogen or R2(CH2)n-; and all other variables are
as defined above;
and the pharmaceutically acceptable salts thereof.
- 30 An illustration of the invention is the compound of the
formula
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WO 96~9140 PCTrUS96/08672
- 16 -
4R R5
R1 1-(CH2)A~ (CH2)n R
where all variables are as defined above; and the pharmaceutically
acceptable salts thereof.
Exemplifying the invention is the compound of the formula
R1 l -(C H2) ~
(CH2)2 ~1
where all variables are as defined above; and the pharmaceutically
acceptable salts thereof.
An example of the invention is the compound of the
formula
4R R5
R2-(CH2)n~ ~(CH2)n R6
where all variables are as defined above; and the pharmaceutically
acceptable salts thereof.
Further illustrating the invention is the compound of the
forrnula
O
C H3--S ' N~ (C H2) n R
CA 02221842 1997-11-18
W O 96~9140 - PCT~US96/08672
wherein R6 is selected from mono-, di- or tri-substituted phenyl
wherein the substituents on the phenyl are independently selected from
halogen, nitro, amino, Cl 4 aL~yl or Cl 4 alkoxy; naphthyl;
thi~n~rhthenyl; benzofuranyl; indolyl; 2-substituted indolyl where the
S substitutent is selected from halogen, Cl 4 alkyl or Cl 4 aL~coxy; or
2,5-disubstituted indolyl where the substituents are independently
selected from hydrogen, halogen, nitro, amino, C1 4 alkyl or
Cl 4 aL~oxy; where all other variables are as defined above;
and the pharmaceutically acceptable salts thereof.
Another illustration of the invention is the compound
selected from
3,4-Dihydro-7-methanesulfonamido- 1 '-[2-(2-methyl-3-
indolyl)ethyl]spiro[(2H)-1 -benzopyran-2,4'-piperidine]-4-one;
3,4-Dihydro-7-methanesulfonamido- 1 '-[2-(2-
methoxyphenyl)ethyl]spiror(2H)- l -benzopyran-2,4'-piperidine] -4-one;
3 ,4-Dihydro-7-methanesulfonamido- 1'-[2-( 1 -naphthyl)ethyl] spiro [(2H)-
1 -benzopyran-2,4'-piperidine] -4-one;
3,4-Dihydro- 1 '-[2-(3-indolyl)ethyl]-7-methanesulfonamidospiro[(2H)- 1-
benzopyran-2,4'-piperidine] -4-one;
3 ,4-Dihydro-7-methanesulfonamido- 1 '-[2-(3-
thi~n~phthyl)ethyl]spiro[(2H)- 1 -benzopyran-2,4'-piperidine]-4-one;
l '-[2-(2-Ethoxyphenyl)ethyl] -3 ,4-dihydro-7 -
methanesulfonamidospiro[(2H)- l -benzopyran-2,4'-piperidine]-4-one;
6- Benzyloxycarbonylamido-3,4-dihydro- l '-[2-(1-
naphthyl)ethyl]spiro[(2H)- l -benzopyran-2,4'-piperidine]-4-one;
3 ,4-Dihydro- l '-[2-(1 -naphthyl)ethyl]-6-phenylsulfonamidospiro[(2H)- 1-
benzopyran-2,4'-piperidine] -4-one;
3 ,4-Dihydro-6-( 1 -methyl-4-imidazolyl)acetamido- 1'-[2-(1-
naphthyl)ethyl]spiro~(2~)- 1 -benzopyran-2,4'-piperidine]-4-one;
3,4-Dihydro-6-(3,5-dimethyl-4-isoxazolyl)sulfonamido-1'-[2-(1-
naphthyl)ethyl]spiro[(2H)- 1 -benzopyran-2,4'-piperidine]-4-one;
3 ,4-Dihydro-6-( 1 -methyl-4-imidazolyl)sulfonamido- 1'-[2-(1-
naphthyl)ethyl]spiro[(2H)- 1 -benzopyran-2,4'-piperidine]-4-one;
CA 02221842 1997-11-18
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- 18 -
3 ,4-Dihydro-6-( 1 -imidazolylmethyl)- 1'-[2-(1 -naphthyl)ethyl]spiro[(2H)-
1 -benzopyran-2,4'-piperidine] -4-one;
3,4-Dihydro- 1'-[2-(1 -naphthyl)ethyl]-6-( 1,2,4-
triazolylmethyl)spiro[(2H)- 1 -benzopyran-2,4'-piperidine]-4-one;
6 -Cyanomethyl-3 ,4-dihydro- 1'- [2-(1 -naphthyl)ethyl] spiro [(2H)- 1 -
benzopyran-2,4'-piperidine]-4-one or
7-Acetamido-3 ,4-dihydro- 1 '-[2-(2-fluorophenyl)ethyl]spiro[(2H)- 1-
benzopyran-2,4'-piperidine] -4-one;
and the pharmaceutically acceptable salts thereof.
Another example of the invention is a pharmaceutical
composition comprising a therapeutically effective amount of any of the
compounds described above and a pharmaceutically acceptable carrier.
More specifically exemplifying the invention is the
composition further comprising a therapeutically effective amount of a
lS testosterone 5-alpha reductase inhibitor. Preferably, the testosterone S-
alpha reductase inhibitor is a type 1, a type 2, both a type 1 and a type 2
(i.e., a three component combination comprising any of the compounds
described above combined with both a type I testosterone S-alpha
reductase inhibitor and a type 2 testosterone 5-alpha reductase inhibitor)
or a dual type 1 and type 2 testosterone S-alpha reductase inhibitor.
More preferably, the testosterone 5-alpha reductase inhibitor is a type 2
testosterone S-alpha reductase inhibitor. Most preferably, the
testosterone 5-alpha reductase inhibitor is finasteride.
Another illustration of the invention are methods of
treating benign prostatic hyperplasia, inhibiting contraction of prostate
tissue or relaxing urethral smooth muscle in a subject in need thereof
which comprises ~dmini~tering to the subject a therapeutically effective
amount of any of the pharmaceutical compositions described above.
More specifically illustratillg the invention are methods of
treating benign prostatic hyperplasia, inhibiting contraction of prostate
tissue or relaxing urethral smooth muscle in a subject in need thereof
which comprises ~lministering to the subject a therapeutically effective
amount of any of the compounds described above. Preferably, in the
methods of treating BPH, inhibiting contraction of prostate tissue or
CA 02221842 1997-11-18
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- 19 -
relaxing urethral smooth muscle, the compound additionally does not
cause a fall in blood pressure at dosages effective to alleviate BPH or
inhibit contraction of prostate tissue.
Another example of the invention are methods of treating
5 benign prostatic hyperplasia, inhibiting contraction of prostate tissue or
relaxing urethral smooth muscle wherein any of the compounds
described above are ~lmini~tered in combination with a testosterone 5-
alpha reductase inhibitor. Preferably, the testosterone 5-alpha reductase
inhibitor is finasteride.
Still another example of the invention is a pharmaceutical
composition made by combining any of the compounds described above
with a pharmaceutically acceptable carrier.
More particularly illustrating the invention is a process for
making a pharmaceutical composition comprising combining any of the
compounds described above and a pharmaceutically acceptable carrier.
More particularly exemplifying the invention is the use of
any of the compounds described above in the preparation of a
medicament for: the treatment of benign prostatic hyperplasia,
inhibiting contraction of prostate tissue, or relaxing urethral smooth
muscle in a subject in need thereof.
An additional illustration of the invention is a drug which is
useful for: treating benign prostatic hyperplasia, inhibiting contraction
of prostate tissue or relaxing urethral smooth muscle in a m~mm~l in
need thereof, the effective ingredient of the said drug being any of the
compounds described above.
DETAILED DESCRIPTION OF THE ~VENTION
The present invention provides compounds for the
treatment of urinary obstruction caused by benign prostatic hyperplasia
- 30 (BPH). Representative compounds of the present invention exhibit high
selectivity for the human alphala adrenergic receptor. This invention
has the advantage over non-selective alpha-l adrenoceptor antagonists of
reduced side effects related to peripheral adrenergic blockade. Such
side effects include orthostatic hypotension, syncope, lethargy, etc.
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- 20 -
Thus, one implication of this selectivity is that these compounds display
selectivity for lowering intraurethral pressure without substantially
affecting diastolic blood pressure.
Representative compounds of this invention display
submicromolar affinity for the human alphala adrenergic receptor
subtype while displaying at least ten-fold lower affinity for the human
alphald and alphalb adrenergic receptor subtypes, and many other G-
protein coupled human receptors. Particular representative compounds
of this invention exhibit nanomolar affinity for the hllm~n alphala
adrenergic receptor subtype while displaying at least 30 fold lower
affinity for the hllm~n alphald and alphalb adrenergic receptor
subtypes, and many other G-protein coupled hllm~n receptors.
Preferred compounds of this invention exhibit Ki's for hurnan alphala
adrenergic receptors which are more than 40 fold lower than for the
hllm~n alphald or alphalb adrenergic receptors, while exhibiting
greater than 100 fold selectivity for the human alphala adrenergic
receptor over all other human G-protein coupled receptor.s tested
(including serotonin~ dopamine, alpha 2 adrenergic, beta adrenergic or
muscarinic receptors).
These compounds are administered in dosages effective to
antagonize the alphala receptor where such treatment is needed, as in
BPH. For use in medicine, the salts of the compounds of this invention
refer to non-toxic "pharmaceutically acceptable salts.'~ Other salts may,
however, be useful in the preparation of the compounds according to
2~ the invention or of their pharmaceutically acceptable salts. Suitable
pharmaceutically acceptable salts of the compounds of this invention
include acid addition salts which may, for example, be formed by
mixing a solution of the compound according to the invention with a
solution of a pharmaceutically acceptable acid such as hydrochloric acid,
sulphuric acid, fumaric acid, maleic acid, succinic acid, acetic acid,
benzoic acid, oxalic acid, citric acid, tartaric acid, carbonic acid or
phosphoric acid. Furthermore, where the compounds of the invention
carry an acidic moiety, suitable pharmaceutically acceptable salts
thereof may include alkali metal salts, e.g. sodium or potassium salts;
CA 02221842 1997-11-18
W O 96~9140 PCT/U',G,'~h~72
~lk~line earth metal salts, e.g. calcium or m~gnesium salts; and salts
formed with suitable organic ligands, e.g. quaternary ammonium salts.
Thus, representative pharmaceutically acceptable salts include the
following:
S Acetate, Benzenesulfonate, Benzoate, Bicarbonate,
Bisulfate, Bitartrate, Borate, Bromide, Calcium, Camsylate, Carbonate,
Chloride, Clav~ n~te, Citrate, Dihydrochloride, Edetate, Edisylate,
Estolate, Esylate, Fumarate, Gluceptate, Gluconate, Glllt~m~te,
Glycollylarsanilate, Hexylresorcinate, Hydr~b~mine, Hydrobromide,
Hydrochloride, Hydroxynaphthoate, Iodide, Isothionate, Lactate,
Lactobionate, Laurate, Malate, Maleate, Mandelate, Mesylate,
Methylbromide, Methylnitrate, Methylsulfate, Mucate, Napsylate,
Nitrate, N-methylglucamine ammonium salt, Oleate, Oxalate, Pamoate
(Embonate), Palmitate, Pantothenate, Phosphate/diphosphate,
Polygalacturonate, Salicylate, Stearate, Sulfate, Subacetate, Succinate,
Tannate, Tartrate, Teoclate, Tosylate, Triethiodide and Valerate.
The present invention includes within its scope prodrugs of
the compounds of this invention. In general, such prodrugs will be
functional derivatives of the compounds of this invention which are
readily convertible in vivo into the required compound. Conventional
procedures for the selection and preparation of suitable prodrug
derivatives are described, for example, in "Design of Prodrugs," ed. H.
Bundgaard, Elsevier, 19~5. Metabolites of these compounds include
active species produced upon introduction of compounds of this
invention into the biological milieu.
Where the compounds according to the invention have at
least one chiral center, they may accordingly exist as enantiomers.
Where the compounds according to the invention possess two or more
chiral centers, they may additionally exist as diastereoisomers. It is to
be understood that all such isomers and mixtures thereof are
encompassed within the scope of the present invention. Furthermore,
some of the crystalline forms for compounds of the present invention
may exist as polymorphs and as such are intended to be included in the
present invention. In addition, some of the compounds of the present
CA 02221842 1997-11-18
W O 96~9140 PCTrUS96/08672
invention may form solvates with water (i.e., hydrates) or common
organic solvents. Such solvates are also encompassed within the scope
of this invention.
The term "aL~yl" shall mean straight or branched chain
S aL~anes of one to ten total carbon atoms, or any number within this
range (i.e., methyl, ethyl, l-propyl, 2-propyl, n-butyl, t-butyl, etc.).
The term "aryl" as used herein, except where otherwise
specifically defined, refers to unsubstituted, mono- or poly-substituted
aromatic groups such as phenyl or naphthyl.
Whenever the term "alkyl" or "aryl" or either of their
prefix roots appear in a name of a substituent it shall be interpreted as
including those limitations given above for "aL~yl" and "aryl."
Designated numbers of carbon atoms (e.g., C1 1o) shall refer
independently to the number of carbon atoms in an alkyl or cyclic alkyl
moiety or to the alkyl portion of a larger substituent in which alkyl
appears as its prefix root.
The term "halogen" shall include iodine~ bromine, chlorine
and fluorine.
The term "substituted" shall be deemed to include multiple
degrees of substitution by a named substitutent.
Where multiple substituent moieties are disclosed or
claimed, the substituted compound can be independently substituted by
one or more of the disclosed or claimed substituent moieties, singly or
plurally.
The term heterocycle, het, or heterocyclic ring, as used
herein, represents an unsubstituted or substituted stable 5- to 7-
membered monocyclic ring system which may be saturated or
unsaturated, and which consists of carbon atoms and from one to four
heteroatoms selected from N, O or S, and wherein the nitrogen and
sulfur heteroatoms may optionally be oxidized, and the nitrogen
heteroatom may optionally be quaternized. The heterocyclic ring may
be attached at any heteroatom or carbon atom which results in the
creation of a stable structure. Examples of such heterocyclic groups
include, but is not limited to, piperidinyl, piperazinyl, oxopiperazinyl,
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- 23 -
oxopiperidinyl, oxopyrrolidinyl, oxoazepinyl, azepinyl, pyrrolyl,
pyrrolidinyl, furanyl, thienyl, pyrazolyl, pyrazolidinyl, imidazolyl,
imidazolinyl, imidazolidinyl, pyridyl, pyrazinyl, pyrimidinyl,
pyridazinyl, oxazolyl, oxazolidinyl, isooxazolyl, isoxazolidinyl,
morpholinyl, thiazolyl, thiazolidinyl, isothiazolyl, thiadiazolyl,
tetrahydropyranyl, thiamorpholinyl, thiamorpholinyl sulfoxide,
thiarnorpholinyl sulfone, and oxadiazolyl. Morpholino is the sarne as
morpholinyl.
The term "subject," as used herein refers to an animal,
preferably a m~mmal, most preferably a human, which has been the
object of treatment, observation or experiment.
The term "therapeutically effective amount" as used
herein means that amount of active compound or pharmaceutical
agent that elicits the biological or medicinal response in a tissue,
system, anim~l or human that is being sought by a researcher,
veterinarian, medical doctor or other clinician, which includes
alleviation of the symptoms of the disease being treated.
As used herein, the term "composition" is intended to
encompass a product comprising the specified ingredients in the
specified amounts, as well as any product which results, directly or
indirectly, from combination of the specified ingredients in the specified
amounts.
The present invention also provides pharmaceutical
compositions comprising one or more compounds of this invention in
association with a pharmaceutically acceptable carrier. Preferably these
compositions are in unit dosage forms such as tablets, pills, capsules,
powders, granules, sterile parenteral solutions or suspensions, metered
aerosol or liquid sprays, drops, ampoules, auto-injector devices or
suppositories; for oral, parenteral, intranasal, sublingual or rectal
~ 30 ~lmini~tration, or for ~lministration by inhalation or insufflation.
Alternatively, the compositions may be presented in a form suitable for
- once-weekly or once-monthly ~lmini~tration; for example, an insoluble
salt of the active compound, such as the decanoate salt, may be adapted
to provide a depot preparation for intramuscular injection. For
CA 02221842 1997-11-18
W O 96~9140 = PCT~US96/08672
- 24 -
preparing solid compositions such as tablets, the principal active
ingredient is mixed with a pharrnaceutical carrier, e.g. conventional
tableting ingredients such as corn starch, lactose, sucrose, sorbitol, talc,
stearic acid, magnesium stearate, dicalcium phosphate or gums, and
5 other pharmaceutical diluents, e.g. water, to form a solid
preformulation composition cont~ining a homogeneous mixture of a
compound of the present invention, or a pharmaceutically acceptable
salt thereof. When referring to these preformulation compositions as
homogeneous, it is meant that the active ingredient is dispersed evenly
10 throughout the composition so that the composition may be readily
subdivided into equally effective unit dosage forms such as tablets, pills
and capsules. This solid preformulation composition is then subdivided
into unit dosage forms of the type described above cont~ining from 0.1
to about 500 mg of the active ingredien~ of the present invention. The
15 tablets or pills of the novel composition can be coated or otherwise
compounded to provide a dosage form affording the advantage of
prolonged action. For example, the tablet or pill can comprise an inner
dosage and an outer dosage component, the latter being in the form of
an envelope over the former. The two components can be separated by
20 an enteric layer which serves to resist disintegration in the stomach and
permits the inner component to pass intact into the duodenum or to be
delayed in release. A variety of materials can be used for such enteric
layers or coatings, such materials including a number of polymeric
acids and mixtures of polymeric acids with such materials as shellac,
2~ cetyl alcohol and cellulose acetate.
The liquid forms in which the novel compositions of the
present invention may be incorporated for ~rlmini~tration orally or by
injection include aqueous solutions, suitably flavoured syrups, aqueous
or oil suspensions, and flavoured emulsions with edible oils such as
30 cottonseed oil, sesarne oil, coconut oil or peanut oil, as well as elixirs
and similar pharmaceutical vehicles. Suitable dispersing or suspending
agents for aqueous suspensions include synthetic and natural gums such
as tragacanth, acacia, alginate, dextran, sodium carboxymethylcellulose,
methylcellulose, polyvinyl-pyrrolidone or gelatin.
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- 25 -
Where the processes for the preparation of the compounds
according to the invention give rise to mixtures of stereoisomers, these
isomers may be separated by conventional techniques such as
preparative chromatography. The compounds may be prepared in
racemic form, or individual enantiomers may be prepared either by
enantiospecific synthesis or by resolution. The compounds may, for
example, be resolved into their component enantiomers by standard
techniques, such as the formation of diastereomeric pairs by salt
formation with an optically active acid, such as (-)-di-p-toluoyl-d-
tartaric acid and/or (+)-di-p-toluoyl-l-tartaric acid followed by
fractional cryst~lli7~tion and regeneration of the free base. The
compounds may also be resolved by formation of diastereomeric esters
or amides, followed by chromatographic separation and removal of the
chiral auxiliary. Alternatively, the compounds may be resolved using a
chiral HPLC column.
During any of the processes for preparation of the
compounds of the present invention, it may be necessary and/or
desirable to protect sensitive or reactive groups on any of the molecules
concerned. This may be achieved by means of conventional protecting
groups, such as those described in Protective Groups in Or~anic
Chemistrv, ed. J.F.W. McOmie, Plenum Press, 1973; and T.W. Greene
& P.G.M. Wuts, Protective Groups in Or~anic Synthesis. John Wiley &
Sons, 1991. The protecting groups may be removed at a convenient
subsequent stage using methods known from the art.
The specificity of binding of compounds showing affinity
for the ala receptor is shown by comparing affinity to membranes
obtained from tranfected cell lines that express the ala receptor and
membranes from cell lines or tissues known to express other types of
alpha (e.g., a1d, a1b) or beta adrenergic receptors. Expression of the
cloned human a1d, a1b, and ala receptors and comparison of their
binding properties with known selective antagonists provides a rational
way for selection of compounds and discovery of new compounds with
predictable pharmacological activities. Antagonism by these compounds
of the human ala adrenergic receptor subtype may be functionally
CA 02221842 1997-11-18
WO 96~9140 - PCTAUS96/08672
- 26 -
demonstrated in anesthetized ~nim~l.c. These compounds may be.used to
increase urine flow without exhibiting orthostatic hypotensive effects.
The ability of compounds of the present invention to
specifically bind to the ala receptor makes them useful for the
S treatrnent of BPH. The specificity of binding of compounds showing
~rr.~ y for the ala receptor is compared against the binding affinities
to other types of alpha or beta adrenergic receptors. The hllm~n alpha
adrenergic receptor of the la subtype was recently identified, cloned
and expressed as described in PCT International Application Publication
Nos. W094/0~040, published 14 April 1994 and WO 94/21660,
published 29 September 1994, each of which is hereby incorporated by
reference. The cloned hurnan ala receptor, when expressed in
m~mms~ n cell lines, is used to discover ligands that bind to the
receptor and alter its function. Expression of the cloned human ald,
alb, and ala receptors and comparison of their binding properties
with known selective antagonists provides a rational way for selection of
compounds and discovery of new compounds with predictable
pharmacological activities.
Compounds of this invention exhibiting selective human
a1a adrenergic receptor antagonism may further be defined by
counterscreening. This is accomplished according to methods known in
the art using other receptors responsible for mediating diverse
biological functions. rSee e.~.~ PCT International Application
Publication No. WO94/10989, published 26 May 1994; U.S. Patent No.
5,403,847, issued April 4, 1995]. Compounds which are both selective
amongst the various hnm~n alphal adrenergic receptor subtypes and
which have low affinity for other receptors, such as the alpha2
adrenergic receptors, the ~-adrenergic receptors, the muscarinic
receptors, the serotonin receptors, and others are particularly
preferred. ~he absence of these non-specific activities may be
confirmed by using cloned and expressed receptors in an analogous
fashion to the method disclosed herein for identifying compounds which
have high affinity for the various human alphal adrenergic receptors.
CA 02221842 1997-11-18
W O 96~9140 PCT/U~Gi'~672
Furthermore, functional biological tests are used to confirm the effects
of identified compounds as alphala adrenergic receptor antagonists.
The present invention also has the objective of providing
suitable topical, oral, systemic and parenteral pharmaceutical
formulations for use in the novel methods of treatment of the present
invention. The compositions cont~ining compounds of this invention
as the active ingredient for use in the specific antagonism of human
alphala adrenergic receptors can be ~lministered in a wide variety
of therapeutic dosage forms in conventional vehicles for systemic
~lministration. For example, the compounds can be administered in
such oral dosage forms as tablets, capsules (each including timed
release and sustained release formulations), pills, powders, granules,
elixirs, tinctures, solutions, suspensions, syrups and emulsions, or by
injection. Likewise, they may also be ~lministered in intravenous
(both bolus and infusion), intraperitoneal, subcutaneous, topical with
or without occlusion, or intramuscular form, all using forms well
known to those of ordinary skill in the pharmaceutical arts. An
effective but non-toxic amount of the compound desired can be
employed a.s an alphala antagonistic agent.
Advantageously~ compounds of the present invention
may be administered in a single daily dose, or the total daily dosage
may be administered in divided doses of two, three or four times
daily. Furtherrnore, compounds for the present invention can be
~lmini.stered in intranasal form via topical use of suitable intranasal
vehicles, or via transdermal routes, using those forms of transdermal
skin patches well known to those of ordinary skill in that art. To be
~clminictered in the form of a transdermal delivery system, the
dosage administration will, of course, be continuous rather than
intermittent throughout the dosage regimen.
The dosage regimen utilizing the compounds of the
present invention is selected in accordance with a variety of factors
including type, species, age, weight, sex and medical condition of the
patient; the severity of the condition to be treated; the route of
a-lministration; the renal and hepatic function of the patient; and the
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W O 96~9140 - PCTAJS96/08672
- 2~ -
particular compound thereof employed. A physician or veterinarian
of ordinary skill can readily determine and prescribe the effective
amount of the drug required to prevent, counter or arrest the
progress of the condition. Optimal precision in achieving
5 concentration of drug within the range that yields efficacy without
toxicity requires a regimen based on the kinetics of the drug's
availability to target sites. This involves a consideration of the
distribution, equilibrium, and elimin~tion of a drug.
In the methods of the present invention, the compounds
10 herein described in detail can form the active ingredient, and are
typically ~lmini.~tered in admixture with suitable pharmaceutical
diluents, excipients or carriers (collectively referred to herein as
"carrier" materials) suitably selected with respect to the intended
form of ~lmini~tration~ that is, oral tablets, capsules, elixirs, syrups
15 and the like, and consistent with conventional pharmaceutical
practices.
For instance, for oral a-lmini.~tration in the form of a
tablet or capsule, the active drug component can be combined with
an oral, non-toxic pharmaceutically acceptable inert carrier such as
20 ethanol, glycerol, water and the like. Moreover, when desired or
necessary, suitable binders, lubricants, disintegrating agents and
coloring agents can also be incorporated into the mixture. Suitable
binders include, without limitation, starch, gelatin, natural sugars
such as glucose or beta-lactose, corn sweeteners, natural and
25 synthetic gums such as acacia, tragacanth or sodium alginate,
carboxymethylcellulose, polyethylene glycol, waxes and the like.
Lubricants used in thes~ dosage forms include, without limitation,
sodium oleate, sodium stearate, magnesium stearate, sodium
benzoate, sodium acetate, sodium chloride and the like.
30 Disintegrators include, without limitation, starch, methyl cellulose,
agar, bentonite, x~nth~n gum and the like.
The liquid forms in suitably flavored suspending or
dispersing agents such as the synthetic and natural gums, for example,
tragacanth, acacia, methyl-cellulose and the like. Other dispersing
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WO 96/39140 - PCT/US96/08672
- 29 -
agents which may be employed include glycerin and the like. For
parenteral ~lmini~tration, sterile suspensions and solutions are desired.
Isotonic preparations which generally contain suitable preservatives are
employed when intravenous ~tlmini~tration is desired.
The compounds of the present invention can also be
~imini~tered in the form of liposome delivery systems, such as small
Imil~mellar vesicles, large unilamellar vesicles and multilamellar
vesicles. Liposomes can be forrned from a variety of phospholipids,
such as cholesterol, stearylamine or phosphatidylcholines.
Compounds of the present invention may also be
delivered by the use of monoclonal antibodies as individual carriers
to which the compound molecules are coupled. The compounds of
the present invention may also be coupled with soluble polymers as
targetable drug carriers. Such polymers can include polyvinyl-
pyrrolidone, pyran copolymer, polyhydroxypropylmethacryl-
amidephenol, polyhydroxy-ethylaspartamidephenol, or polyethyl-
eneoxidepolylysine substituted with palmitoyl residues.
Furthermore, the compounds of the present invention may be
coupled to a class of biodegradable polymers useful in achieving
controlled release of a drug, for example, polylactic acid,
polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters,
polyacetals, polydihydro-pyrans, polycyanoacrylates and cross-linked
or amphipathic block copolymers of hydrogels.
Clompounds of this invention may be ~(lmini~tered in
any of the foregoing compositions and according to dosage regimens
established in the art whenever specific blockade of the human
alphala adrenergic receptor is required.
The daily dosage of the products may be varied over a wide
range from 0.01 to 1,000 mg per adult human/per day. For oral
~lministration, the compositions are preferably provided in the form of
tablets cont~inin~ 0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0,
50.0 and 100 milligrams of the active ingredient for the symptomatic
adjustment of the dosage to the patient to be treated. A medicament
typically contains from about 0.01 mg to about 500 mg of the active
CA 02221842 1997-11-18
W O 96~9140 PCTAJS96/08672
- 30 -
ingredient, preferably, from about 1 mg to about 100 mg of active
ingredient. An effective amount of the drug is ordinarily supplied at a
dosage level of from about 0.0002 mg/kg to about 250 rng/kg of body
weight per day. Preferably, the range is from about 0.001 to 100
S mg/kg of body weight per day, and especially from about 0.001 mg/kg
to 7 mg/kg of body weight per day. The compounds may be
admi .istered on a regimen of 1 to 4 times per day.
Compounds of this patent disclosure may be used alone at
a~l,rol,.iate dosages defined by routine testing in order to obtain
optimal antagonism of the human ala adrenergic receptor while
minimi7ing any potential toxicity. In addition, co-~-lmini~tration or
sequential arlmini~tration of other agents which alleviate the effects of
BPH is desirable. Thus, in one embodiment, this includes
~lmini~tration of compounds of this invention and a human testosterone
S-cx reductase inhibitor. Included with this embodiment are inhibitors
of 5-alpha reductase isoenzyme 2. Many such compounds are now well
known in the art and include such compounds as PROSCAR(~), (also
known as finasteride, a 4-Aza-steroid; see US Patents 4,377,584 and
4,760,071, for example, hereby incorporated by reference). In addition
to PROSCAR~, which is principally active in prostatic tissue due to its
selectivity for human 5-a reductase isozyme 2, combinations of
compounds which are specifically active in inhibiting testosterone 5-
alpha reductase isozyme 1 and compounds which act as dual inhibitors
of both isozymes 1 and 2, are useful in combination with compounds of
this invention. Compounds that are active as 5a-reductase inhibitors
have been described in W093/23420, EP 0572166; WO 93/23050;
W093/23038,, W093/23048; WO93/23041, W093/23040;
W093/23039; W093/23376; WO93/23419, EP0572165; WO93/23051,
each of which is hereby incorporated by reference.
The dosages of the alphala adrenergic receptor and
testosterone 5-alpha reductase inhibitors are adjusted when combined
to achieve desired effects. As those skilled in the art will appreciate,
dosages of the 5-alpha reductase inhibitor and the alphala adrenergic
receptor antagonist may be independently optimized and combined to
CA 02221842 1997-11-18
W O 96~9140 PCTAUS96/08672
achieve a synergistic result wherein the pathology is reduced more
than it would be if either agent were used alone. In accordance with
the method of the present invention, the individual components of the
combination can be ~lmini.stered separately at different times during
S the course of therapy or concurrently in divided or single
combination forms. The instant invention is therefore to be
understood as embracing all such regimes of simultaneous or
alternating treatment and the term "~flmini~tering" is to be
interpreted accordingly.
Thus, in one preferred embodiment of the present
invention, a method of treating BPH is provided which comprises
a~lmini~tering to a subject in need of treatrnent any of the compounds
of the present invention in combination with finasteride effective to
treat BPH. The dosage of finasteride ~lministered to the subject is
about 0.01 mg per subject per day to about 50 mg per subject per
day in combination with an ala antagonist. Preferably, the dosage
of finasteride in the combination is about 0.2 mg per subject per day
to about 10 mg per subject per day, more preferably, about 1 to
about 7 mg per subject to day, most preferably, about 5 mg per
subject per day.
For the treatment of benign prostatic hyperplasia,
compounds of this invention exhibiting alphala adrenergic receptor
blockade can be combined with a therapeutically effective arnount of
a Sa-reducta.se 2 inhibitor, such as finasteride, in addition to a Sa-
reductase 1 inhibitor, such as 4,7~-dimethyl-4-aza-5a-cholestan-3-
one, in a single oral, systemic, or parenteral pharmaceutical dosage
formulation. Alternatively, a combined therapy can be employed
wherein the alphala adrenergic receptor antagonist and the Sa-
reductase 1 or 2 inhibitor are zl~lministered in separate oral,
- 30 systemic, or parenteral dosage formulations. See, e.g., U.S. Patent
No.'s 4,377,5~s4 and 4,760,071 which describe dosages and
forrnulations for Sa-reductase inhibitors.
Abbreviations used in the instant specification, particularly
the Schemes and Examples, are as follows:
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Ac = acetyl
Ar = aryl
Boc or BOC = t-butyloxycarbonyl
CBZ = benzyloxycarbonyl
Cbz-CI = benzyloxycarbonyl chloride or benzyl chloroformate
DMF = N,N-dimethylformamide
Et = ethyl
Et3N = triethylamine
EtOAc = ethyl acetate
EtOH = ethanol
het = heterocycle
HPLC = high pressure liquid chromatography
HOAc = acetic acid
i-PrOH = isopropanol
Me = methyl
MeOH = methanol
Nu = nucleophile
NMR = nuclear magnetic resonance
PEI = polyethylenimine
Ph = phenyl
TFA = trifluoroacetic acid
THF = tetrahydrofuran
TLC = thin layer chromatography
The compounds of the present invention can be prepared
readily according to the following reaction schemes and examples, or
modifications thereof, using readily available starting materials,
reagents and conventional synthesis procedures. In these reactions, it is
30 also possible to make use of variants which are themselves known to
those of ordinary skill in this art, but are not mentioned in greater
detail.
The compounds and pharmaceutically acceptable salts of the
present invention can be synthesized according to the general methods
CA 02221842 1997-11-18
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outlined in Schemes 1-6. The 6-carbon substituted compounds of the
instant invention can be prepared as shown in Scheme 1. Accordingly,
compound I is prepared by the method of Acta Pharm. Suec., 15, 13
(1978). A solution of I in a polar, aprotic solvent, preferably N,N-
5 dimethylformamide, is prepared following the usual techniques for theexclusion of moisture. To this solution is added a nucleophile, such as
imidazole or 1,2,4-triazole, and an inorganic base, preferably sodium
carbonate. Alternatively, a nucleophile such as potassium cyanide is
added and the inorganic base is not needed. The reaction mixture
10 temperature is m~int~ined at 25~C. Extractive workup and purification
according to standard procedures affords II. The spiro[(2H)-l-
benzopyran-2,4'-piperidine]-4-one moiety is formed by treating a
solution of II, following the usual techniques for the exclusion of
moisture, in a protic solvent such as an alcohol, preferably methanol,
15 with a dialkylamine base, preferably pyrrolidine, followed by a
protected form of 4-piperidone, preferably protected as the f-
butyloxycarbonyl derivative on nitrogen. The reaction mixture is
m~int~ined at 25~C when the volatiles are removed and purification
according to standard procedures affords III. The piperidyl nitrogen is
20 liberated by treatment of III with an acid, such as HCI or trifluoroacetic
acid, and extractive workup according to standard procedures affords
IV. The piperidine IV is derivatized on N-l' following the usual
techniques for the exclusion of moisture, by treatment of a solution of
IV in a polar solvent, preferably N,N-dimethylforrnamide, with an
25 alkylating agent, such as an alkyl bromide or iodide, preferably an
arylethyl bromide, and the addition of a base like diisopropylethyl~mint
or triethylamine. Alternatively, an inorganic base such as lithium
carbonate can be used. The reaction mixture is m~int~ined at an
elevated temperature, preferably 70~C, and extractive workup and
30 purification according to standard procedures affords V.
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SCHEME 1
[~Me 37% CH20 Cl~ Me Nu, DMF
OH conc. HCI OH
O =CNBOC ~
Nu'~~Me ~ ' Nu~BOC
Nu~~CH2)2Br Nu~ 1~'
IV
The 7-acetamide compounds of the instant invention can be
prepared as shown in Scheme 2. Accordingly, 3-acetamidophenol is
suspended in an aprotic organic solvent, preferably dichloromethane,
5 and treated with an acylating agent such as acetyl chloride following the
usual techniques for the exclusion of moisture. A strong Lewis acid,
preferably aluminum trichloride, is added portionwise to keep the
vigorous exothermic reaction under control at ambient temperature.
The reaction mixture is then heated and the volatiles are removed by
10 distillation. The reaction mixture is then further heated, preferably to
140~C, until the reaction mixture is thick and stirring difficult. The
mixture is then cooled, preferably to 0~C, and treated with crushed ice.
The resultant solid is collected and dried according to standard
procedures to provide VI. The spiro[(2H)-l-benzopyran-2,4'-
15 piperidine]-4-one moiety is formed employing the methodology
described above to afford VII. The piperidyl nitrogen is selectively
CA 02221842 1997-11-18
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liberated by treatment of VII with an acid, such as HCI or
trifluoroacetic acid, preferably at or below ambient temperature.
Extractive workup according to standard procedures affords VIII. The
piperidine VIII can be converted to IX employing the alkylating
5 methodology described above.
SCHEME 2
O ~
~qAcCI, AICI3 ,~ O ~,,NBOC
AcHN ~OHAcHN ~OH ~;~
Vl H
~ HCI ,~ Ar(CH2)2Br
AcHN O~\ AcHN O H
Vlll
o
AcHN ~ ~N Ar
IX
The 7-methylsulfonamide compounds of the inst~nt
invention can be prepared as shown in Scheme 3. The acetamide VI can
be converted to the corresponding aniline by treatrnent with an acid,
10 preferably HCl, in a protic solvent system such as a mixture of ethanol
and water, at elevated temperature, followed by treatment with
methanesulfonyl chloride and a tertiary amine base, preferably
pyridine, in a polar aprotic solvent such as dichloromethane, following
the usual techniques for the exclusion of moisture. Extractive workup
15 and purification according to standard procedures affords X. The
spiro[(2H)-l-benzopyran-2,4'-piperidine]-4-one moiety is formed
employing the methodology described above to afford XI. Liberation
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of the piperidine nitrogen (to afford XII) and subsequent aLkylation (to
afford XIII) are accomplished employing the methodology described
above.
SCHEME 3
AcHN~ 2 MeSO2CI Me NHJ3 ~
X H
S2 ~ Me'S'N~NH
Ar(CH2)2Br
MeO2SHN ~N~Ar
S Xlll
Other 7-position derivatives of the instant invention can be
prepared according to Scheme 4. Both the acetarnide and the t-
butyloxycarbonyl group of VII can be removed by treatrnent with an
10 acid, preferably HCl, in a protic solvent system such as a mixture of
ethanol and water, at elevated temperature to afford XIV after standard
extractive procedures. The piperidine nitrogen N-l' can be aLkylated
selectively by treatment of a solution of XIV in a polar solvent,
CA 02221842 1997-11-18
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preferably N,N-dimethylformamide, with an alkylating agent, such as
an alkyl bromide or iodide, and the addition of a base such as
diisopropylethyl amine or triethyl~mine following the usual techniques
for the exclusion of moisture. Alternatively, an inorganic base such as
S lithium carbonate can be used. The reaction mixture is maintained at an
elevated temperature, preferably 70~C, and extractive workup and
purification according to standard procedures affords XV. The aniline
nitrogen is derivatized by dissolving XV in an aprotic organic solvent,
preferably dichloromethane following the usual techniques for the
10 exclusion of moisture. To this solution is then added a organic base
such as pyridine followed by an acylating agent, such as a carboxylic
acid chloride, carboxylic acid anhydride or sulfonic acid chloride, or
the like. The reaction mixture temperature is m~int~ined between 0~C
and 27~C, preferably 24~C. Extractive workup and purification
15 according to standard procedures affords XVI.
SCHEME 4
O ,0,
~ HCI ~ Ar(CH2)2Br
AcHN~O~\ heat H N~O~NH
Vll XIV
~ RSO2CI or
H2N ~ OJ~N~ ~Cl
XV R'HN~OJ~N Ar
or RCO XVI
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- 3~ -
The 6-nitrogen substituted compounds of the instant
invention can be prepared as shown in Scheme ~. Aniline XVII
(prepared according to that procedure described in J. M. Elliott et. al.,
J. Med. Chem. 1992, 35, 3973-3976) is dissolved in a polar aprotic
5 solvent, preferably dichloromethane, treated with an equal volume of a
saturated aqueous solution of an inorganic base such as sodium
carbonate and the two-phase mixture stirred preferably at 0~C and
treated with a suitable chloroformate, such as benzyl chloroformate.
Extractive workup according to standard procedures affords XVIII.
10 The spiro[(2H)-l-benzopyran-2,4'-piperidine]-4-one product XIX is
formed employing the methodology described above as are the
liberation of the piperidine nitrogen (to afford XX) and subsequent
alkylation (to afford XXI). The carbobenzyloxy group in XXI is
removed by dissolving XXI in a protic organic solvent such as an
15 alcohol, preferably ethanol, cont~ining a concentrated inorganic acid,
preferably HCI. To this solution is added a catalyst to effect
hydrogenolysis, preferably palladium black, and the mixture is shaken
under a hydrogen atmosphere, preferably at 55 pounds/square inch
(psi), in a Parr apparatus which affords XXII after removal of the
20 catalyst by filtration. The aniline nitrogen is derivatized by dissolving
XXII in an aprotic organic solvent, preferably dichloromethane,
following the usual techniques for the exclusion of moisture. To this
solution is then added a tertiary amine base such as pyridine followed by
an acylating agent, such as a carboxylic acid chloride, carboxylic acid
25 anhydride or sulfonic acid chloride, or the like. The reaction mixture
temperature is maintained between 0~C and 27~C, preferably 24~C.
Extractive workup and purification according to standard procedures
affords XXIII.
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SCHEME 5
H2N ~ CbZ-cl CBzHN ~¢~ O =CNBOC
XVIIXVIII
CBZHN ~U~ HCI
W~o~
NBOC
XIX
o
CBZH N ~C H2)2Br ~d black
XX
o
H2N ~ RCOCI ~
O N-- Ar R' is RS02 N~ Ar
XXII or RCO XXIII
The alkyl bromides used in the instant invention can be
~ prepared according to the general methods outlined in Scheme 6.
5 Accordingly, a carboxylic acid XXIV, preferably an aryl acetic acid, is
converted to an alkyl ester, preferably the methyl ester. This can be
accomplished by dissolving acid XXIV in a mixture of polar organic
solvents, preferably methanol and chloroform, and treating with a
solution of a diazomethane derivative, such as
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(trime~ylsilyl)diazomethane, and the reaction mixture m~int~ined at
arnbient temperature. The excess diazo compound is quenched with an
organic acid, preferably acetic acid, and removal of yolatiles affords
ester XXV. Alternatively, esters can be prepared by dissolving the acid
S XXIV in an organic alcohol, such as methanol, treating with a catalytic
amount of inorganic acid, preferably sulfuric acid, and maint~inin~ the
reaction temperature preferably above 65~C. Removal of the volatiles
affords XXV. Conversion of the ester to the alcohol XXVI can be
accomplished by treating a solution of ester XXV in a nonpolar organic
10 solvent, such as diethyl ether or tetrahydrofuran, with a metal hydride
reducing agent~ such as lithium aluminum hydride, following the usual
techniques for the exclusion of moisture. Extractive workup and
purification according to standard procedures affords XXVI.
Bromides XXVII can be prepared by dissolving the alcohol in an
15 aprotic organic solvent, preferably dichloromethane, and treating the
solution with a bromine source, preferably carbon tetrabromide,
followed by a phosphine, such as triphenylphosphine, following the
usual techniques for the exclusion of moisture. l['he reaction
temperature is maintained between 0~C and 27~C, preferably 24~C.
20 Removal of volatiles and purification according to standard procedures
affords XXVII.
SCHEME 6
Ar~ TMSCHN,2 Ar~ LiAlH4.
XXIV XXV
Ar~OH CBr4 A ~ Br
PPh3
XXVI XXVII
Where a carboxylic acid chloride is needed, it is prepared
from the corresponding carboxylic acid by standard synthetic
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methodology. Additionally, where an aromatic ether is needed, it is
prepared from the corresponding phenol by standard synthetic
methodology.
The following examples are provided to further define the
5 invention without, however, limiting the invention to the particulars of
these examples.
EXAMPLE 1
3,4-Dihydro-7-methanesulfonamido- 1 '-[2-(2-methyl-3-
indolyl)ethyllspiror(2H)-1 -benzopvran-2~4'-piperidinel-4-one
Step 1: A suspension of 10 g (66 mmol) 3-acetamidophenol
in 30 mL dichloromethane and 21 mL (240 mmol) acetyl chloride in a
500 mL 3-neck round bottom flask was stirred by means of an overhead
mechanical stirrer, affixed with an Ar inlet and a glass stopper.
Aluminum trichloride (30.4 g, 230 mmol) was added portion wise over
20 minutes, reaction was vigorously exothermic and evolves gas. After
addition was complete, the reaction mixture was homogeneous, a
heating mantle was affixed to the reaction and the stopper was removed
to expose the reaction to the atmosphere. The reaction mixture was
heated with stirring to evaporate the volatiles and then further heated to
140~C (mantle temperature) until reaction mixture was thick and
stirring was difficult. Heating was continued for an additional 10
minlltes when the heating mantle was removed and the reaction cooled
to room temperature. The flask was then placed in an ice-water bath
and crushed ice (300 mL) was added to the reaction mixture which
facilitates stirring and causes a yellow solid to precipitate out. This
solid was collected by filtration, rinsed with water and dried by
azeotropic removal of toluene (2 x 200 mL) to provide N-(4-acetyl-5-
hydroxyphenyl)acetamide as a pale yellow solid.
- Step 2: To a solution of 14 g (76 mmol) N-(4-acetyl-5-
hydroxyphenyl)acetamide in 250 mL methanol was added 6.3 mL (76
mmol) pyrrolidine and 15.1 g (76 mmol) N-t-butyloxycarbonyl-4-
piperidone. The reaction mixture was heated on a sand bath to 60~C
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(bath temperature) for 4~ h when the reaction was cooled to room
temperature and the volatiles removed by rotary evaporation to provide
an insoluble precipitate in the methanol solution. The precipitate was
collected and washed with methanol to give an off-white solid and the
5 combined methanol washes concentrated at reduced pressure. The
resultant oil was purified by pressurized silica gel chromatography,
using a gradient elution of 50-70% ethyl acetate in hexane to obtain an
additional foamy white solid, identical spectroscopically to the first
solid. These solids were combined to give 7-acetamido-1'-t-butyloxy-
carbonyl-3,4-dihydrospiro[(2H)- 1 -benzopyran-2,4'-piperidine]-4-one.
Step 3: To a suspension of 15.2 g (40.6 mmol) of 7-
acetamido- 1 '-t-butyloxycarbonyl-3,4-dihydro-[(2H)- 1 -benzopyran-2,4'-
piperidine]-4-one in 600 mL ethanol in a 2 L round bottom flask was
added 300 mL water and 300 mL concentrated HCl. The flask was
15 affixed with a water-cooled condenser and stirred while heating at
reflux for 14 h. The reaction was then cooled to room temperature, the
volatiles removed by rotary evaporation and the resulting solid
azeotroped with toluene (3 x 200 mL) to provide the dihydrochloride
salt of 7-amino-3,4-dihydrospiro[(2H)-l-benzopyran-2,4'-piperidine]-4-
20 one as a pale yellow solid.
Step 4: To a solution of dihydrochloride salt of 7-amino-
3,4-dihydro-[(2H)-l-benzopyran-2,4'-piperidine]-4-one (570 mg, 1.
mmol) in DMF (5 mL) was added diisopropylethylamine (1.02 mL,
5.83 mmol), and 3-(2-bromoethyl)-2-methylindole (493 mg, 2.07
25 mmol). The reaction mixture was warrned to 65~C for 17 h. The
volatiles were removed under reduced pressure and the residue was
partitioned between ethyl acetate and 10% aqueous citric acid solution.
The layers were separated and the aqueous layer was diluted with
saturated NaCI solution (25~o by volume), basified with lN NaOH and
30 extracted with dichloromethane (6 x 50 mL). The combined organic
layers were then dried over Na2SO4 and concentrated under reduced
pressure to give 7-amino-3,4-dihydro-1'-[2-(2-methyl-3-
indolyl)ethyl]spiro[(2H)- 1 -benzopyran-2,4'-piperidine]-4-one.
HPLC: retention time = 6.55 min
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Step 5: To a solution of 7-amino-3,4-dihydro-1'-[2-(2-
methyl-3 -indolyl)ethyl] spiro[(2H)- 1 -benzopyran-2,4'-piperidine] -4-one
(140 mg, 0.37 mmol) in dry dichloromethane (5 mL) and pyridine (0.3
mL), cooled on an ice-water bath under argon, was added
methanesulfonyl chloride (32 rnL, 0.41 mmol). After 1 h, the ice-water
bath was removed and reaction mixture warmed to room temperature.
The solvent was removed under reduced pressure and the residue was
taken up in dichloromethane (100 mL) and washed with saturated
NaHCO3 solution (1 x 50 mL), brine (1 x 50 mL), and dried over
Na2SO4. The volatiles were removed under reduced pressure and the
resulting solid was purified by pressurized silica gel chromatography,
using a gradient elution of methanol (1-6%) in chloroform saturated
with NH3 to afford 3,4-dihydro-7-methanesulfonamido-1'-[2-(2-methyl-
3-indolyl)ethyl]spiro[(2H)-I-benzopyran-2,4'-piperidine]-4-one as a pale
yellow solid.
lH NMR HCI salt: (40~0 MHz, CD30D) 7.79 (d, J=g.73 Hz, IH), 7.76
(d, J= 7.21 Hz, lH), 7.24 (dd, J=6.~, 1.00 Hz, lH), 7.07 (d, J= 2.02
Hz, lH), 7.01 (m, 2H), 6.~3 (dd, J=~.57, 2.19 Hz, lH), 3.64 (br d, J=
12.93 Hz, 2H), 3.46 (br d, J=13.94 Hz, 2H), 3.3~ (m, 2H), 3.21 (m,
2H), 3.10 (s, 3H), 2.~4 (s, 2H), 2.42 (s, 3H), 2.39 (d, J=14.7~ Hz, 2H),
2.04 (bt, J= 12.93 Hz, 2H).
Analysis: C25H29N3O4 S, 0.~ H2O, calc: C 62.29, H 6.40, N ~.72.
found: C 62.32, H 6.25, N ~.73.
HPLC: retention tiIne = 6.7~ min, purity = 96%
FAB MS: m/z = 46~ (M + H+)
EXAMPLE 2
3,4-Dihydro-7-methanesulfonamido- 1 '-[2-(2-
~ 30 methoxyphenyl)ethyllspiror(2H)- 1 -benzopyran-2.4'-piperidinel-4-one
Step 1: To a solution of 1.0 g (5.2 mmol) of N-(4-acetyl-5-
hydroxyphenyl)acetamide (prepared in above example. Step 1) in 50
mL absolute ethanol was added 25 mL water and 25 mL 12N HCl. The
35 reaction mixture was refluxed for 20 h when the volatiles were
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- 44 -
removed at reduced pressure and the residue was partitioned between
200 mL dichloromethane and 100 mL saturated NaHCO3 solution. The
layers were separated and the aqueous layer extracted with
dichloromethane (2 x 50 mL). The organic layers were combined,
dried over Na2SO4, filtered and concentrated to provide 1-(4-amino-2-
hydroxyphenyl)ethanone.
HPLC: retention time = 4.25 min, purity = 100%
Step 2: A solution of 1-(4-amino-2-hydroxyphenyl)-
ethanone (2.0 g, 10 mmol) in dry dichloromethane (100 mL) and
pyridine (2.05 mL) was cooled in an ice-water bath under argon and
treated with methanesulfonyl chloride (O.g mL, 10.2 mmol). After 1 h,
the ice bath was removed and reaction mixture warmed to room
temperature. The reaction mixture wa~s diluted with dichloromethane
(100 mL) and extracted with 50 mL lN HCI. The aqueous layer was
washed with dichloromethane (50 mL) and the organic layers were
combined, washed with brine (1 x 25 mL) and dried over Na2SO4. The
volatile,s were removed under reduced pressure and the resulting solid
was triturated and filtered from dichloromethane to afford N-(4-acetyl-
5-hydroxyphenyl)methanesulfonamide as a purple solid.
HPLC: retention time = 5.23 min
FAB MS: m/z = 230 (M + H+)
Step 3: To a solution of N-(4-acetyl-5-hydroxyphenyl)-
methanesulfonamide (1.4 g, 6.2 mmol) in 15 mL methanol was added
pyrrolidine (0.52 mL, 6.2 mmol) and a solution of N-t-butyloxy-
carbonyl~-piperidone (1.2 g, 6.2 mmol) in 50 mL methanol. The
reaction mixture was warmed to 65~C for 17 h. The volatiles were
removed under reduced pressure and the residue was partitioned
between 200 mL ethyl acetate and 100 mL saturated NaHCO3 solution.
The organic layer was washed with saturated NaHCO3 solution (2 x 50
mL), with brine (1 x 50 mL), dried over Na2SO4 and concentrated
under reduced pressure. The resultant oil was purified by pressurized
silica gel chromatography, using 2:1 hexanes:ethyl acetate as the eluent
to obtain l'-t-butyloxycarbonyl-3,4-dihydro-7-methanesulfonamido-
spiro[(2H)-l-benzopyran-2,4'-piperidine]-4-one as a white solid.
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HPLC: retention time = 8.25 min
FAB MS: m/z=411(M+H+)
Step 4: 1 '-t-Butyloxycarbonyl-3,4-dihydro-7-methane-
sulfonamidospiro[(2H)-l-benzopyran-2,4'-piperidine]-4-one (1.95 g, 4.8
5 mmol) was dissolved in 25 mL isopropanol and 12 mL 8N HCI was
added. The reaction mixture was stirred at room temperature for 17 h.
The volatiles were removed under reduced pressure to afford the
hydrochloride salt of 3,4-dihydro-7-methanesulfonamidospiro[(2H)-l-
benzopyran-2,4 '-piperidine] -4-one .
10 FABMS:m/z=311(M+H+)
Step 5: To a solution of the hydrochloride salt of 3,4-
dihydro-7-methanesulfonamidospiro[(2H)- I -benzopyran-2,4'-
piperidine]-4-one (100 mg, 0.29 mmol) in DMF (2 mL) was added
Li2CO3 (47 mg, 0.64 mmol), KI ( catalytic amount), and 2-(2-
bromoethyl)methoxybenzene (75 mg, 0.35 mmol). The reaction
mixture was warmed to 65~C for 17 h. The volatiles were removed
under reduced pressure and the residue was partitioned between 50 rnL
dichloromethane and 25 mL saturated NaHCO3 solution. The organic
layer was washed with brine (1 x 25 mL), dried over Na2SO4 and
20 concentrated under reduced pressure. The resultant oil was purified bypressurized silica gel chromatography, using a gradient elution of 1-4%
methanol in dichloromethane containing 0.5% concentrated ammonium
hydroxide to obtain 3,4-dihydro-7-methanesulfonamido-1'-[2-(2-
methoxyphenyl)ethyl]spirol(2H)- 1 -benzopyran-2,4'-piperidine]-4-one.
Analysis: C23H2gN2OsS, 1.7 H2O: calc: C 53.99, H 5.83, N 5.63.
found: C 53.99, H 6.38, N 5.48.
HPLC: retention time = 6.51 min, purity = 9g%
FAB MS: mlz = ~45 (M + H+)
EXAMPLE 3
3,4-Dihydro-7 -methanesulfonamido- 1 '- [2-(2-methyl -3 -
indolyl)ethyllspiror(2H)- 1 -benzopyran-2.4'-piperidinel-4-one
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The compound of EXAMPLE 1 was also prepared
according to the process described in Exarnple 2 by sub~ illg 3-(2-
bromoethyl)-2-methylindole for 2-(2-bromoethyl)methoxybenzene in
Step S of EXAMPLE 2. The compound prepared in this m~nn~r was
5 identical in all respects to that prepared according to EXAMPLE 1.
EXAMPLE 4
3,4-Dihydro-7-methanesulfonamido- 1 '-[2-(1 -naphthyl)ethyl]spiro[(2H)-
10 1-benzopyran-2~4'-piperidinel-4-one
Following the procedure of EXAMPLE 2, but substituting
1-(2-bromoethyl)naphthalene for 2-(2-bromoethyl)methoxybenzene in
Step 5, the title compound was obtained.
lH NMR HCl salt: (400 MHz. CD30D) g.12 (br d, J= ~.22 Hz, l H),
7.92 (br d, J= 7.22 Hz, lH), 7.~4 (br d, J= 7.21 Hz, lH), 7.~0 (d, J=
g.S6 Hz, lH), 7.62 (bt, J= 6.~9 Hz, lH) 7.52 (m, 3H), 7.0~s (bs, lH),
6.~s3 (dd, J= ~.73, 2.02 Hz, lH), 3.6~ (m, 2H), 3.52 (m, 6H), 3.10 (s,
3H), 2.~s6 (bs, 2H), 2.42 (m, 2H), 2.0g (m, 2H).
Analysis: C26H2~N2O4S HCl 1.00 H2O: calc:C 60.16, H 6.02, N
5.40. found: C 60.13, H 5.~9, H 5.30.
HPLC: retention time = 7.24 min, purity = 96%
FAB MS: m/z = 465 (M + H+)
EXAMPLE 5
3,4-Dihydro~ [2-(3 -indolyl)ethyl] -7-methanesulfonarnidospiro [ (2H)- 1 -
benzopvran-2~4'-piperidinel -4-one
30 Following the procedure of EXAMPLE 2, but substituting 3-(2-
bromoethyl)indole for 2-(2-bromoethyl)methoxybenzene in Example 2,
Step 5, the title compound was obtained.
lH NMR (400 MHz, CDC13) Pi.02 (bs, lH), 7.~4 (d~ J= g.S6,1H), 7.62
(d, J= 7.55 Hz, lH), 7.37 (d, J= ~.06 Hz, lH), 7.20 (t, J= 7.22 Hz, lH),
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7.12 (t, J=7.89 Hz, lH), 7.05 (d, J= 1.6~ Hz, lH), 6.88 (d, J=2.1~ Hz,
lH), 6.69 (dd, J= 8.56, 2.18 Hz, lH), 3.14 (s, 3H), 2.99 (bt, J= 7.56
Hz, 2H), 2.79 (m, 4H), 2.71 (s, 2H), 2.55 (bt, J= 11.42 Hz, 2H), 2.0g
(d, J= 13.09 Hz, 2H), 1.81 (dt, J=14.27, 3.69 Hz, 2H).
Analysis: C24H27N3O4S 1.0 H2O. calc: C 54.60, H 6.15, N 7.96.
found: C 54.56, H 5.80, N 7.95.
TLC: Rf = 0.12 (95:5:0.5 CH2C12:MeOH:NH40H)
HPLC: retention time = 6.36 min, purity = 96%
FAB MS: m/z = 454 (M + H+)
EXAMPLE 6
3,4-Dihydro-7-methanesulfonamido- 1 '-[2-(3-
thianaphthyl)ethyll spirol (2H)- I -benzopyran-2.4'-piperidinel -4-one
The title compound was prepared according to the
procedure of EXAMPLE 2 by substituting 3-(2-bromoethyl)-
thi~n~phthene for 2-(2-bromoethyl)methoxybenzene in Step 5.
lH NMR HCI salt (400 MHz, CD30D) 7.91 (dt, J= 7.~9, 0.85 Hz, 2H),
7.~0 (d, J= ~.56 Hz, lH), 7.49 (s, lH), 7.47 (dd, J= 7.05, 1.01 Hz, lH),
7.43 (dd, J= ~.40, 1.35 Hz, lH) 7.39 (br d, J= 7.06 Hz, lH), 7.09 (bs,
lH), 6.~s3 (dd, J= ~.56, 2.01 Hz, lH), 3.63 (m, 4H), 3.g~s (m, 4H), 3.11
(s, 3H), 2.89 (s, 2H), 2.41 (br d, J=14.61 Hz, 2H), 2.11 (m, 2H).
Analysis: C24H26N2O4S2 HCI 0.65 H2O . calc: C 55.56, H 5.50, N
5.40. found: C 55.53, H 5.39, N 5.35.
TLC: Rf = 0.26 (95:5:0.5 CHC13:MeOH:NH40H)
HPLC: retention time = 7.32 min, purity = 97%
FAB MS: rn/z = 471 (M + H+)
EXAMPLE 7
1 '-[2-(2-Ethoxyphenyl)ethyl] -3,4-dihydro-7-
methanesulfonamidospiror(2H)- I -benzopyran-2.4'-piperidinel-4-one
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The title compound was prepared according to the
procedure of EXAMPLE 2 by sub~LiLu~ g 2-(2-bromoethyl)ethoxy-
benzene for 2-(2-bromoethyl)methoxybenzene in Step 5.
lH NMR HCI salt (400 MHz, CD30D) 7.~gO (d, J= 8.56 HZ, lH), 7.26
(m, 2H), 7.06 (d, J=1.85 Hz, lH), 6.9Ps (d, ~.05 Hz, lH), 6.92 (dt, J=
7.39 Hz, lH), 6.~3 (dd, J= 8.57, 2.02 Hz, lH), 4.12 (q, J=7.05 Hz, 2H),
3.61 (br d, J=13.09 Hz, 2H), 3.37 (m, 4H), 3.11 (s, 5H), 2.83 (s, 2H),
2.3~ (br d, J= 14.94 Hz, 2H), 2.03 (dt, J=13.60, 4.36 Hz, 2H), 1.45 (t,
J=6.g~ Hz, 3H).
Analysis: C24H30N2o5s HCl 1.9 H2O. calc: C 54.46, H 6.63, N
5.29. found: C 54.50, H 6.07, N 5.22.
HPLC: retention time = 7.10 min, purity = 98%
FAB MS: m/z = 459 (M + H+)
EXAMPLE ~
6-Benzyloxycarbonylamido-3,4-dihydro- 1 '-[2-(1 -
naphthyl)ethyllspiror(2H)- I -benzopyran- 4'-piperidinel-4-one
1-(5-Amino-2-hydroxyphenyl)ethanone hydrochloride was prepared
according to the procedure described in J. M. Elliott et. al., J Med.
Chem. 1992, 35, 3973-3976.
Step 1: A solution of 1-(5-amino-2-hydroxyphenyl)-
ethanone hydrochloride (1.5 g, ~.0 mrnol) in 50 mL dichloromethane
was treated with 50 mL saturated Na2CO3 and cooled on an ice-water
bath when benzyl chloroformate (1.1 mL, ~.0 mmol) was added. The
reaction mixture was stirred in the ice-water bath for 3 h when it was
diluted with 50 mL dichloromethane and 50 mL water and the layers
separated. The organic layer was then washed with water (1 x 50 mL),
brine (I x 50 mL) and dried over sodium sulfate. The volatiles were
removed under reduced pressure and 1-(5-benzyloxycarbonylamido-2-
hydroxyphenyl)ethanone was obtained ~s a yellow solid.
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HPLC: retention time = 9.14 min, purity = >95%
FAB MS: m/z = 2~6 (M + H+)
Step 2: To a solution of 1-(5-benzyloxycarbonylamido-2-
hydroxyphenyl)ethanone (2.2 g, 7.5 mmol) in 50 mL methanol was
added pyrrolidine (0.63 mL, 7.5 mmol) and a solution of N-t-butyloxy-
carbonyl-4-piperidone (1.5 g, 7.5 mmol) in 50 mL methanol and the
reaction mixture was warmed to 65~C overnight. The volatiles were
removed under reduced pressure and the residue was partitioned
between ethyl acetate (250 mL) and saturated NaHCO3 solution (100
mL). The organic layer was washed with saturated NaHCO3 solution (2
x 50 mL) and brine (1 x 50 mL), dried over Na2SO4 and concentrated
under reduced pressure. The residue was taken up in methanol and the
resulting precipitate collected and washed with methanol to provide a
yellow solid and the combined methanol washes concentrated at reduced
pressure. The resultant oil was purified by pressurized silica gel
chromatography, using 10% ethyl acetate in hexane as the eluent to
obtain an additional white solid, identical spectroscopically to the first.
These solids were combined to yield 6-benzyloxycarbonylarnido-1'-t-
butyloxycarbonyl -3 ,4-dihydrospiro [ (2H) -1 -benzopyran-2 ,4 '-piperidine] -
4-one.
HPLC: retention time = 10.~S4 min
FAB MS: m/z = 466(M + H+)
Step 3: To a solution of 6-benzyloxycarbonylamido-1'-t-
butyloxycarbonyl-3,4-dihydrospiro[(2H)- 1 -benzopyran-2,4'-piperidine]-
4-one (1.0 g, 2.1 mmol) in dichloromethane (60 mL) was added
trifluoroacetic acid (30 mL) and the reaction mixture was stirred at
room temperature for 2 h when the volatiles were removed under
reduced pressure. The resulting oil was taken up in dichloromethane
(200 mL) and carefully treated with saturated NaHCO3 solution (100
mL). The organic layer was washed with additional saturated NaHCO3
(2 x 50 mL), brine (1 x 50 mL) and dried over Na2SO4. Concentration
under reduced pressure gave 6-benzyloxycarbonylamido-3,4-dihydro-
spiro[(2H)-l-benzopyran-2,4'-piperidine]-4-one as a yellow solid.
HPLC: retention time = 6.77 min
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Step 4: To a solution of 6-benzyloxycarbonylamido-3,4-
dihydrospiro[(2H)-l-benzopyran-2,4'-piperidine]-4-one (0.62 g, 1.7
mmol) in DMF (10 mL) was added Li2CO3 (0.15 g, 2.0 mmol), KI
(catalytic amount), and 1-(2-bromoethyl)naphthalene (0.48 g, 2.0
5 mrnol). The reaction mixture was warmed to 65~C for 17 h. The
volatiles were removed under reduced pressure and the residue was
partitioned between dichloromethane (100 mL) and saturated NaHCO3
solution (50 mL). The organic layer was washed with additional
saturated NaHCO3 solution (50 mL), brine (50 mL), dried over
Na2SO4 and concentrated under reduced pressure. The resultant oil
was purified by pressurized silica gel chromatography, using a gradient
elution of 1-5% methanol in dichloromethane Cont~inin,~ 0.5%
concentrated amrnonium hydroxide to obtain 6-benzyloxycarbonyl-
amido-3,4-dihydro- 1 '-[2-(1 -naphthyl)ethyl]spiro[(2H)- 1 -benzopyran-
2,4'-piperidine] -4-one.
lH NMR (400 MHz, CDCl3) 8.04 (d, J= 7.39 Hz, lH),7.gS (dd, J=
7.89, 1.51 Hz, lH), 7.72 (d, J= ~.05 Hz, 2H), 7.67 (d, J= 2.69 Hz, lH),
7.54- 7.45 (m, 2H), 7.42-7.31 (m, 6H), 6.9g (d, J= ~.90 Hz, lH), 6.92
(m, lH), 3.31- 3.27 (m, 2H), 2.94 (s, 2H), 2.~S7 (s, 2H), 2.76 (m, 4H),
2.55 (t, J=9.91 Hz, 2H), 2.09 (d, J=12.76 Hz, 2H), 1.79 (dt, J= 14.61,
4.37 Hz, 2H).
Analysis: C33H32N2O4 HCI, 0.~ H2O. calc: C 69.35, H 6.10, N
4.90. found: C 69.3~, H 6.09, N 5.0~.
TLC: Rf = 0.34 (95:5:0.5 CH2C12:MeOH:NH4OH)
25 HPLC: retention time = 9.15 min, purity = 96%
FAB MS: m/z=521 (M+H+)
EXAMPLE 9
3,4-Dihydro- 1 '-[2-(1 -naphthyl)ethyl]-6-phenylsulfonarnidospiro[(2H)- 1 -
benzopyran-2.4'-piperidinel -4-one
Step 1: To a solution of 6-benzyloxycarbonylamido-3,4-
dihydro- 1 '-[2-(1 -naphthyl)ethyl]spiro[(2H)- 1 -benzopyran-2,4'-
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piperidine]-4-one (0.47 g, 0.89 rnmol) in ethanol (50 mL) was added
12N HCl (2 mL) and palladium black (76 mg). The reaction mixture
was shaken at 55 psi hydrogen gas in a Parr apparatus for 25 h when the
reaction mixture was flushed with argon, filtered through celite and
5 washed with copious arnounts of warm methanol. The volatiles were
removed under reduced pressure to give the hydrochloride salt of 6-
amino-3,4-dihydro-1 '-[2-(1 -naphthyl)ethyl]-spiro[(2H)-l -benzopyran-
2,4 '-piperidine] -4 -one .
HPLC: retention time = 9.29 min
FAB MS: m/z =387(M + H+)
Step 2: A solution of the hydrochloride salt of 6-amino-
3,4-dihydro-1 '-[2-(1-naphthyl)ethyl]spiro[(2H)-1 -benzopyran-2,4'-
piperidine]-4-one (0.10 g, 0.22 mmol) in dry dichloromethane (2 mL)
and pyridine (0.3 mL) was cooled on an ice-water bath under argon and
benzenesulfonyl chloride (34 mL, 0.26 mmol) was added. After 1 h, the
bath was removed and reaction mixture warmed to room temperature
when the volatiles were removed under reduced pressure. The resultant
oil was purified by pressurized silica gel chromatography, using 1 %
methanol in dichloromethane containing 0.5% concentrated ammonium
hydroxide as the eluent to obtain 3,4-dihydro-1'-[2-(1-naphthyl)ethyl]-
6-phenylsulfonamidospiro~(2H)- 1 -benzopyran-2,4'-piperidine]-4-one.
lH NMR (400 MHz, CD30D) 8.11 (d, J=8.06 Hz, lH), 7.92 (d, J= 7.55
Hz, lH), 7.83 (dd, J=6.88, 1.67 Hz, lH), 7.75 (s, lH), 7.73 (m, lH),
7.62- 7.43 (m, 8H), 7.36 (dd, J= 8.90, 2.69 Hz, lH), 7.05 (d, J=8.90 Hz,
lH), 3.59-3.40 (m, 8H), 2.86 (bs, 2H), 2.31 (m, 2H), 2.17 (m, 2H).
Analysis: C31H30N2O4S HCI 1.85 H20. calc: C 62.42, H 5.~6, N
4.70. found: C 62.45, H 6.83, N 4.57.
HPLC: retention time = 8.09 min, purity = 96%
FAB MS: m/z = 527(M + H+)
EXAMPLE 10
3,4-Dihydro-6-(1 -methyl-4-imidazolyl)acetamido- 1 '-[2-(1 -
naphthvl)ethyllspiror(2H)- I -benzopyran-2.4'-piperidinel-4-one
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The title compound was prepared according to the
procedure of EXAMPLE 9 by substituting 1-methyl-4-imidazoleacetyl
chloride for benzenesulfonyl chloride in Step 2.
lH N~R (400 MHz, CD30D) 8.84 (s, lH), 8.16 (d, J= 8.40 Hz, lH),
8.09 (d, J=2.68 Hz, lH), 7.92 (d, 8.05 Hz, lH), 7.83 (d, J= 7.89 Hz,
lH), 7.77 (dd, J= 8.89, 2.68 Hz, lH), 7.61 (dt, J=6.89, 1.34 Hz, lH),
7.54 (d, J=8.06 Hz, lH), 7.51-7.44 (m, 2H), 7.23- 7.10 (m, 4H), 3.93 (s,
3H), 3.91 (s, 2H), 3.74- 3.43 (m, gH), 2.90 (s, 2H), 2.39 (m, 2H), 2.14
(bt, J=11.75 Hz, 2H).
Analysis: C3lH32N4O3 2 HCl, 1.2 H2O 0.45 EtOAc. calc: C 62.38,
H 6.27, N 8.72. found: C 61.28, H 6.22, N 8.65
HPLC: retention time = 6.44 min, purity = 92%
FAB MS: rn/z = 509 (M + H+)
EXAMPLE 11
3,4-Dihydro-6-(3,5-dimethyl-4-isoxazolyl)sulfonamido- 1 '-[2-(1 -
naphthyl)ethyllspirol ~2H~- I -benzopyran-2.4'-piperidinel-4-one
The title compound was prepared according to the
procedure of EXAMPLE 9 by substituting 3,5-dimethylisoxazole-4-
sulfonyl chloride for benzenesulfonyl chloride in Step 2.
1H NMR (400 MHz, CDC13) 8.12 (d, J=8.23 Hz, lH), 7.92 (d, J= 8.06
Hz, lH), 7.83 (dd, J=7.22, 1.85 Hz, lH), 7.61 (m, lH), 7.54 (m, 3H),
7.48 (d, J=8.89 Hz, lH), 7.37 (dd, J= 8.90, 2.86 Hz, lH), 7.14 (d,
J=8.89 Hz, lH), 3.52 (m., 7H), 2.91 (s, 2H), 2.78 (m, lH), 2.47 (s, 3H),
2.34 (m, 2H). 2.24 (s, lH), 2.11 (m, 2H).
Analysis: C30H31N3O5S HCl 0.~5 H20. calc: C 60.31, H 5.69, N
7.03. found: C 60.35, H 5.56, N 6.92.
HPLC: retention time = ~~59 min, purity = 96%
FAB MS: m/z = 546 (M + H+)
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EXAMPLE 12
3,4-Dihydro-6-(1 -methyl-4-irnidazolyl)sulfonamido- 1 '-t2-(1 -
naphthyl)ethyllspiror(2H)- 1 -benzopyran-2.4'-piperidinel-4-one
s
The title compound was prepared according to the
procedure of EXAMPLE 9 by substituting 1-methyl-4-
imidazolesulfonyl chloride for benzenesulfonyl chloride in Step 2.
lH NMR (400 MHz, CD30D) 8.22 (s, lH), 8.15 (d, J= 8.39 Hz, lH),
7.91 (d, J= ~S.06 Hz, lH), 7.83 (d, J= 8.90 Hz, 2H), 7.52 (m, 6H) 7.12
(d, J = 12.90 Hz, 2H), 3.79 (s. 3H). 3.64 (m, 4H), 3.47 (m, 4H), 2.87 (s,
2H), 2.35 (bt, J=11.25 Hz, 2H), 2.11 (bt, J=11.76 Hz, 2H).
Analysis: C29H30N4O4S 2 HCI 1.5 H2O. calc: C 55.23, H 5.59, N
8.89. found: C 55.25, H 5.49, N 8.90.
HPLC: retention time = 6.69 min, purity = 95%
FAB MS: m/z = 531 (M + H+)
EX~MPLE 13
3,4-Dihydro-6-(1 -imidazolylmethyl)- I '-[2-(1 -naphthyl)ethyl]spiro[(2H)-
1 -benzopyran-2,4'-piperidinel -4-one
Step 1: 1-(5-chloromethyl-2-hydroxyphenyl)ethanone was
prepared by the method of Acta Pharm. Suec., 15, 13 (1978).
Step 2: To a solution of 3 g (16 mmol) 1-(5-chloromethyl-
2-hydroxyphenyl)ethanone in DMF at room temperature was added
3.45 g (33 mmol) anhydrous sodium carbonate followed by 1.2 g (18
mmol) imidazole. The solution was stirred 4 h when the volatiles were
removed by rotary evaporation and the crude reaction mixture
partitioned between 200 mL dichloromethane and 100 mL water. The
layers were separated, the organic layer washed with 100 mL brine,
- dried over MgSO4, filtered and concentrated under reduced pressure.
The resultant oil was purified by pressurized silica gel chromatography,
using a gradient elution of 3-5% methanol in dichloromethane
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cont~ining 0.5% concentrated ammonium hydroxide to obtain 1-[(2-
hydroxy-5-(1-imidazolylmethyl)phenyl]ethanone as a pale yellow solid.
HPLC: retention time = 2.95 min
Step 3: A solution of 2.6 g (12 mmol) 1-[(2-hydroxy-5-(1-
5 imidazolylmethyl)phenyl]ethanone in 30 mL methanol was treated with1.0 mL (12 mrnol) pyrrolidine followed by 2.4 g (12 mmol) N-t-
butyloxycarbonyl-4-piperidone. The reaction mixture was stirred at
room temperature for 20 h when the volatiles were removed by rotary
evaporation. The resultant oil was purified by pressurized silica gel
10 chromatography, using a gradient elution of 3-4~o rnethanol in
dichloromethane containing 0.5% concentrated ammonium hydroxide to
obtain l'-t-butyloxycarbonyl-3,4-dihydro-6-(1-imidazolylmethyl)-
spiro[(2H)-l-benzopyran-2,4'-piperidine]-4-one as a pale yellow foarn.
HPLC: retention time = 6.9 min
Step 4: A solution of 4.4 g (11 mmol) I'-t-butyloxy-
carbonyl-3,4-dihydro-6-( 1 -imidazolylmethyl)spiro[(2H)- 1 -benzopyran-
2,4'-piperidine]-4-one in 100 mL was treated with 90 mL ~N HCI and
the mixblre stirred at room temperature 3 h when the volatiles were
removed by rotary evaporation. The resultant oil was partitioned
20 between 200 mL dichloromethane and 100 mL saturated NaHCO3
solution. The layers were separated, the aqueous layer extracted with
an additional 100 mL dichloromethane, the organic layers combined,
dried over MgSO4, filtered and concentrated under reduced pressure to
provide 3 ,4-dihydro-6-( 1 -imidazolylmethyl)-spiro [ (2H)- 1 -benzopyran-
25 2,4'-piperidine]-4-one as an off-white solid.
HPLC: retention time = 2.75 min
Step 5: To a solution of 200 mg (0.7 mmol) of 3,4-
dihydro-6-( 1 -imidazolylmethyl)spiro [ (2H)- 1 -benzopyran-2,4'-
piperidine]4-one and 0.1~ mL (1.0 mmol) diisopropylethylamirle irl 5
30 rnL dr~ DMF was added 174 mg (0.7 mmol) 1-(2-bromoethyl)-
naphthalene and the reaction warmed to 70~C for 23 h. The volatiles
were removed at reduced pressure and the resultant oil taken up in 50
mL dichloromethane, washed with saturated aqueous NaHCO3 (1 x 25
mL), dried over MgSO4 and concentrated at reduced pressure. The oil
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was puri~led by pressurized silica gel chromatography using an eluent
of 3% methanol in dichloromethane cont~ining 0.5% concentrated
NH40H and then the HCI salt prepared and triturated with diethyl ether
from meth nol to provide t.he dihydroch!or;de salt of 3,4-dihydro=6=(1=
imidazolylmethyl)- 1 '-[2-(1 -naphthyl)ethyl]spiro[(2H)- 1 -benzopyran-
2,4'-piperidine]-4-one as an off-white solid.
Analysis: C29H29N3O2 2HCI; 2.35 H2O, calc: C 61.45, H 6.35, N 7.41.
found: C 61.45, H 5.99, N 7.52.
HPLC: retention time = 6.24 min, purity = 99%
10 FAB MS: m/z = 452 (M + H+)
EXAMPLE 14
3,4-Dihydro- 1 '-[2-(1 -naphthyl)ethyl] -6-(1,2,4-
15 triazolylmethyl )spirol (2H)- I -benzopyran-2.4'-piperidinel -4-one
Following the procedure of EXAMPLE 13, but substituting
1,2,4-triazole for imidazole in Step 2, the title compound was obtained.
Analysis: C2XH2~N4O2 3HCl; 0.35 H2O, calc: C 59.1~, H 5.62, N 9.86.
20 found: C 59.19, H 5.65, N 9.~ 1.
HPLC: retention time = 6.9 min, purity = 94%
FAB MS: m/z = 453 (M + H+)
EXAMPLE 1
6-Cyanomethyl-3,4-dihydro- 1 '-[2-(1 -naphthyl)ethyl] spiro[(2H)- 1 -
benzopyran-2.4'-piperidinel -4-one
Following the procedure of EXAMPLE 13, but substituting
30 potassium cyanide for imidazole and sodium carbonate in Step 2, the
title compound was obtained.
Analysis: C27H26N202 HCI; 0.7 H20, calc: C 70.56, H 6.23, N 6.10.
found: C 70.62, H 6.26, N 6.20.
HPLC: purity = 95%
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EXAMPLE 16
7-Acetamido-3 ,4-dihydro- 1 '-[2-(2-fluorophenyl)ethyl]spiro[(2H)- 1-
benzopyran-2.4'-piperidinel-4-one
Step 1: A suspension of 7-acetamido- 1 '-t-
butyloxycarbonyl-3,4-dihydrospiro[(2H)- 1 -benzopyran-2,4'-piperidine]-
4-one (4.3 g, 11.5 mmol)(prepared as shown n Example 1, Steps 1 & 2)
10 in 200 mL ethyl acetate was cooled on an ice-water bath and HCI (g)
bubbled through the suspension via a glass pipet for 10 min. The ice-
water bath was removed and the suspension stirred --t room temperature
1 h when the volatiles were removed at reduced pressure and 7-
acetamido-3,4-dihydrospiro[(2H)- 1 -benzopyran-2,4'-piperidine]-4-one
15 obtained as a white powder.
Step 2: To a solution of 200 mg (0.6 mmol) of 7-
acetamido-3,4-dihydrospiro[(2H)- I -benzopyran-2,4'-piperidine]-4-one
and 0.28 mL (1.6 mmol) diisopropylethylamine in 5 mL dry DMF was
added 170 mg (0.~ mmol) 2-(2-bromoethyl)fluorobenzene and the
20 reaction warmed to 60~C for 65 h. The volatiles were removed at
reduced pressure and the resultant oil taken up in 50 mL
dichloromethane and washed with saturated aqueous NaHCO3 (1 x 25
mL). The aqueous layer was extracted with dichloromethane (3 x 50
mL) and the combined organic layers dried over MgSO4 and
25 concentrated at reduced pressure. The resultant oil was purified by
pressurized silica gel chromatography using a gradient of 0.5-4%
methanol in dichloromethane Cont~ining 0.5% concentrated NH40H and
then the HCI salt prepared and triturated with diethyl ether from
methanol to provide the hydrochloride salt of 7-acetamido-3,4-dihydro-
30 1 '-[2-(2-fluorophenyl)ethyl]spiro~(2H)- 1 -benzopyran-2,4'-piperidine]-4-
one as an off-white solid.
Analysis: C23H25N203F HCI, 0.75 H2O, calc: C 61.~, H 6.21, N 6.27.
found: C 61.85, H 6.I0, N 6.22.
HPLC: retention time = 6.31 min, purity = 98%
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FAB MS: m/z = 397 (M ~ H+)
EXAMPLE 17
5 3-(2-bromoethyl)-2-methvlindole
Step 1: To a solution of 1.0 g (5.3 mmol) of 2-methyl-3-
indole acetic acid in 3:1 (v:v) methanol:chloroform (50 mL) was added
a 2.0M solution of (trimethylsilyl)diazomethane in hexanes (2.7 mL, 5.4
10 mmol) and the mixture stirred at room temperature for 1 h when the
yellow color of the solution was quenched by careful dropwise addition
of concentrated HOAc. The volatiles were removed under reduced
pressure to provide methyl 2-methyl-3-indoleacetate.
Step 2: To a solution of 1.1 g (5.3 mmol) of methyl 2-
15 methyl-3-indoleacetate in diethyl ether (50 mL) was added a lM
solution of lithium aluminum hydride in tetrahydrofuran (13 mL, 13
mmol) and the reaction stirred at room temperature 2 h. The reaction
is treated carefully with a saturated solution of sodium potassium
tartrate (150 mL total) and diluted with 100 mL ether. The two-phase
20 mixture was stirred 30 min and then the layers separated, the organic
layer dried over Na2SO4, filtered and concentrated to provide 3-(2-
hydroxyethyl)-2-methylindole.
Step 3: A solution of 3-(2-hydroxyethyl)-2-methylindole
(0.92 g, 5.3, rnmol) in dichloromethane (50 mL) was treated with
25 carbon tetrabromide (2.3 g, 6.~ mmol) and cooled on an ice-water bath.
Triphenylphosphine (1.8 g, 6.~ mmol) is added slowly and the reaction
warmed to room temperature overnight when the volatiles are removed
and the resultant solids were purified by pressurized silica gel
chromatography using a gradient of 1-10% ethyl acetate in hexane to
30 provide 3-(2-bromoethyl)-2-methylindole as a colorless oil which was
used immediately as it readily decomposes upon storage.
EXAMPLE 18
35 2-(2-bromoethvl)methoxybenzene
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_ 5~ _
2-(2-bromoethyl)methoxybenzene was prepared according
to EXAMPLE 17, Step 3 using 2-methoxyphenethyl alcohol instead of
3 -(2-hydroxyethyl)-2-methylindole.
EXAMPLE 19
1 -(2-bromoethyl)naphthalene
1-(2-bromoethyl)naphthalene was prepared according to
EXAMPLE 17, Step 3 using l-naphthaleneethanol instead of 3-(2-
hydroxyethyl)-2-methylindole.
EXAMPLE 20
3 -(2-bromoethyl)thianaphthene
3-(2-bromoethyl)thi~n~phthene was prepared according to
EXAMPLE 17, Steps 1-3 using thianaphthele-3-acetic acid instead of 2-
20 methyl-3-indole acetic acid.
EXAMPLE 21
2-(2-bromoethyl)ethoxybenzene:
Step 1: A solution of methyl 2-hydroxyphenylacetate (1.0
g, 6.0 mmol) in acetone. (30 mL) was treated with ethyl iodide (4.7 mL,
60 mmol) and potassium carbonate (4.5 g, 33 mmol), the flask affixed
with a water-cooled condenser and the mixture reluxed 17 h. The
30 mixture is cooled to room temperature, concentrated at reduced
pressure and the resultant oil partitioned between dichloromethane (150
mL) and brine (75 mL). The layers were separated, the organic layer
dried over Na2SO4, filtered, concentrated and the resultant oil was
purified by pressurized silica gel chromatography using a gradient of
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10-50% ethyl acetate in hexane to provide methyl 2-ethoxyphenylacetate
as a colorless oil.
2-(2-bromoethyl)ethoxybenzene was prepared according to
EXAMPLE 17, Steps 2 and 3 using methyl 2-ethoxyphenylacetate
5 instead of methyl 2-methyl-3-indoleacetate.
EXAMPLE 22
2-(2-bromoethyl)fluorobenzene
2-(2-bromoethyl)fluorobenzene was prepared according to
EXAMPLE 17, Step 3 using 2-fluorophenethyl alcohol instead of 3-(2-
hydroxyethyl)-2-methylindole.
EXAMPLE 23
I-Methyl-4-imidazoleacetyl chloride:
Step 1: To a suspension of the hydrochloride salt of 1-
methyl-4-imidazole acetic acid (120 mg, 0.66 mmol) in
dichloromethane (2 mL) cooled on an ice-water bath was added oxalyl
chloride (0.12 mL) and dry DMF (1 drop). The reaction was stirred in
the ice-water bath 30 min then warrned to room temperature and
allowed to stir until the mixture was homogeneous when the volatiles
were removed under reduced pressure. The resultant oil was used
immediately in EXAMPLE 9, Step 2 instead of benzenesulfonyl
chloride to provide the title compound.
EXAMPLE 24
- 30
As a specific embodiment of an oral composition, 100 mg
- of the compound of EXAMPLE 1 is formulated with sufficient finelydivided lactose to provide a total arnount of 5~0 to 590 mg to fill a size
O hard gel capsule.
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EXAMPLE 25
Screening assay: Alpha la Adrener~ic Receptor Binding
Membranes prepared from the stably transfected human ala cell line
(ATCC CRL 1 1 140) were used to identify compounds that bind to the
hllm~n alphala adrenergic receptor. These competition binding reactions
(total volume = 200 ,ul) contained 50 mM Tris-HCI pH. 7.4, 5 mM EDTA,
150 mM NaCl, 100 pM [125 I]-HEAT, membranes prepared from the ala
cell line and increasing amounts of unlabeled ligand. Reaction.s were
incubated at room temperature for one hour with shaking. Reactions were
filtered onto Wh~tm~n GF/C glass fiber filters with a Inotec 96 well cell
harvester. Filters were washed three times with ice cold buffer and bound
radioactivity was determined (Ki). Representative compounds of the
present invention were found to have Ki values < S nM.
EXAMPLE 26
Selective Binding a~savs
Membranes prepared frorn stably transfected human ald
and alb cell lines (ATCC CRL 1113~ and CRL 11139, respectively)
were used to identify compounds that selectively bind to the hllm~n
alphala adrenergic receptor. These competition binding reactions (total
volume = 200 ~1) contained 50 mM Tris-HCI pH. 7.4, 5 mM EDTA,
150 mM NaCl, 100 pM ~125 I]-HEAT, membranes prepared from cell
lines transfected with the respective alpha 1 subtype expression plasmid
and increasing amounts of unlabeled ligand. Reactions were incubated
at room temperature for one hour with shaking. Reactions were
filtered onto Wh~ n GF/C glass fiber filters with a Inotec 96 well
cell harvester. Filters were washed ~ree times with ice cold buffer and
bound radioactivity was determined (Ki).
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EXAMPLE 27
EXEMPLARY COUNTERSCREENS
5 1. Assay Title: Dopamine D2, D3, D4 in vitro screen
Objective of the Assav:
The objective of this assay is to elimin~te agents which
specifically affect binding of [3H] spiperone to cells expressing human
10 dopamine receptors D2, D3 or D4.
Method:
Modified from VanTol et al (1991); Nature (Vol 350) Pg
610-613.
Frozen pellets containing specific dopamine receptor
subtypes stably expressed in clonal cell lines are Iysed in 2 mL Iysing
buffer (lOmM Tris-HCI/5mM Mg, pH 7.4). Pellets obtained after
centrifuging these membranes (15' at 24,450 rpm) are resuspended in
50mM Tris-HCI pH 7.4 cont~ining EDTA, MgCI[2], KCI, NaCI, CaC1[2]
and ascorbate to give a 1 Mg/mL suspension. The assay is initiated by
adding 50-75 ,ug membranes in a total volume of 500 ,uL cont~ining 0.2
nM [3H]-spiperone. Non-specific binding is defined using 10 ~lM
apomoIphine. The assay is terrnin~tt-d after a 2 hour incubation at
room temperature by rapid filtration over GF/B filters presoaked in
0.3% PEI, using 50mM Tris-HCI pH 7.4.
2. Assay Title: Serotonin 5HTla
Objective of the Assav
The objective of this assay is to elimin~te agents which
specifically affect binding to cloned human 5HTla receptor
Method:
Modified from Schelegel and Peroutka Biochemical
Pharmacology 35: 1943-1949 (19~6).
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~mm~ n cells expressing cloned human SHTla receptors
are lysed in ice-cold 5 mM Tris-HCI, 2 mM EDTA (pH 7.4) and
homogenized with a polytron homogenizer. The homogenate is
centrifuged at 1000Xg for 30', and then the supernatant is centrifuged
again at 38,000Xg for 30'. The binding assay contains 0.25 nM [3H]~-
OH-DPAT (g-hydroxy-2-dipropylamino-1,2,3,4-tetrahydronaphthalene)
in 50 mM Tris-HCl, 4 mM CaC12 and lmg/mL ascorbate. Non-specific
binding is defined using 10 ~lM propranolol. The assay is termin~ted
after a 1 hour incubation at room temperature by rapid filtration over
1 0 GF/Cfilters
EXAMPLE 2
EXEMPLARY FUNCTIONAL ASSAYS
In order to confirm the specificity of compounds for the
human alphala adrenergic receptor and to define the biological activity
of the compounds, the following functional tests may be performed:
1. In vitro Rat, Dog and Human Prostate and Dog Wrethra
Taconic Farrns Sprague-Dawley male rats, weighing 250-
400 grams are sacrificed by cervical dislocation under anesthesia
(methohexital; 50 mg/kg, i.p.). An incision is made into the lower
abdomen to remove the ventral lobes of the prostate. Each prostate
removed from a mongrel dog is cut into 6-8 pieces longitudinally along
the urethra opening and stored in ice-cold oxygenated Krebs solution
overnight before use if necessary. Dog urethra proximal to prostate is
cut into approximately 5 mm rings, the rings are then cut open for
contractile measurement of circular muscles. Human prostate chips
from transurethral surgery of benign prostate hyperplasia are also
stored overnight in ice-cold Krebs solution if needed.
The tissue is placed in a Petri dish cont~ining oxygenated
Krebs solution [NaCI, 118 mM; KCl, 4.7 mM; CaCl2, 2.5 mM;
KH2PO4, 1.2 mM; MgSO4, 1.2 mM; NaHCO3, 2.0 mM; dextrose, 11
mM] warmed to 37~C. Excess lipid material and connective tissue are
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carefully removed. Tissue segments are attached to glass tissue holders
with 4-0 surgical siL~ and placed in a 5 ml jacketed tissue bath
containing Krebs buffer at 37~C, bubbled with 5% C02/95% ~2- The
tissues are connected to a St~th~m-Gould force transducer; 1 gram (rat,
S human) or 1.5 gram (dog) of tension is applied and the tissues are
allowed to equilibrate for one hour. Contractions are recorded on a
Hewlett-Packard 7700 series strip chart recorder.
After a single priming dose of 3 ~lM (for rat), 10 ,uM (for
dog) and 20 ~M (for hllm~n) of phenylephrine, a cumulative
10 concentration response curve to an agonist is generated; the tissues are
washed every 10 minutes for one hour. Vehicle or antagonist is added
to the bath and allowed to incubate for one hour, then another
cumulative concentration response curve to the agonist is generated.
ECso values are calculated for each group using GraphPad
15 Inplot software. pA2 (-log Kb) values were obtained from Schild plot
when three or more concentrations were tested. When less than three
concentrations of antagonist are tested, Kb values are calculated
according to the following formula Kb = rBl,
x-l
20 where x is the ratio of ECso of agonist in the presence and absence of
antagonist and [B] is the antagonist concentration.
2. Measurement of Intra-Urethral Pressure in Anesthetized Dogs
25 PURPOSE: Benign prostatic hyperplasia causes a decreased urine flow
rate that may be produced by both passive physical obstruction of the
prostatic urethra from increased prostate mass as well as active
obstruction due to prostatic contraction. Alpha adrenergic receptor
antagonists such as prazosin and terazosin prevent active prostatic
30 contraction, thus improve urine flow rate and provide symptomatic
relief in man. However, these are non-selective alpha- 1 receptor
- antagonists which also have pronounced vascular effects. Because we
have identified the alpha-la receptor subtype as the predominent
subtype in the human prostate, it is now ~ossible to specifically target
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this receptor to inhibit prostatic contraction without concomitant
changes in the vasculature. The following model is used to measure
adrenergically mediated changes in intra-urethral pressure and arterial
pressure in anesthetized dogs in order to evaluate the efficacy and
5 potency of selective alpha adrenergic receptor antagonists. The goals
are to: 1 ) identify the alpha-l receptor subtypes responsible for
prostatic/urethral contraction and vascular responses, and 2) use this
model to evaluate novel selective alpha adrenergic antagonists. Novel
and standard alpha adrenergic antagonists may be evaluated in this
1 0 manner.
METHODS: Male mongrel dogs (7-12 kg) are used in this study.
The dogs are anesthetized with pentobarbital sodium (35 mg/kg, i.v.
plus 4 mg/kg/hr iv infusion). An endotracheal tube is inserted and the
15 ~nim~l ventilated with room air using a Harvard instruments positive
displacement large ~nim~l ventilator. Catheters (PE 240 or 260) are
placed in the aorta via the femoral artery and vena cava via the femoral
veins (2 catheters, one in each vein) for the measurement of arterial
pressure and the ~lministration of drugs, respectively. A supra-pubic
20 incision ~1/2 inch lateral to the penis is made to expose the urethers,
bladder and urethra. The urethers are ligated and cannulated so that
urine flows freely into beakers. The dome of the bladder is retracted to
facilitate dissection of the proximal and distal urethra. Umbilical tape is
passed beneath the urethra at the bladder neck and another piece of
25 umbilical tape is placed under the distal urethra approximately 1-2 cm
distal to the prostate. The bladder is incised and a Millar micro-tip
pressure transducer is advanced into the urethra. The bladder incision
is sutured with 2-0 or 3-0 silk (purse-string suture) tQ hold the
transducer. The tip of the transducer is placed in the prostatic urethra
30 and the position of the Millar catheter is verified by gently squeezing
the prostate and noting the large change in urethral pressure.
Phenylephrine, an alpha-1 adrenergic agonist, is
~lmini~tered (0.1-100 ug/kg, iv; 0.0~ ml/kg volume) in order to
construct dose response curves for changes in intra-urethral and arterial
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pressure. Following z~lministration of increasing doses of an alpha
adrenergic antagonist (or vehicle), the effects of phenylephrine on
arterial pressure and intra-urethral pressure are re-evaluated. Four or
five phenylephrine dose-response curves are generated in each ~nim~l
5 (one control, three or four doses of antagonist or vehicle). The relative
antagonist potency on phenylephrine induced changes in arterial and
intra-urethral pressure are determined by Schild analysis. The farnily
of averaged curves are fit simultaneously (using ALLFIT software
package) with a four paramenter logistic equation constraining the
10 slope, minimum response, and maximum response to be constant among
curves. The dose ratios for the antagonist doses (rightward shift in the
dose-response curves from control) are calculated as the ratio of the
ED50's for the respective curves. These dose-ratios are then used to
construct a Schild plot and the Kb (expressed as ug/kg, iv) determined.
15 The Kb (dose of antagonist causing a 2-fold rightward shift of the
phenylephrine dose-response curve) is used to compare the relative
potency of the antagonists on inhibiting phenylephrine responses for
intra-urethral and arterial pressure. The relative selectivity is
calculated as the ratio of arterial pressure and intra-urethral pressure
20 Kb's. Effects of the alpha- 1 antagonists on baseline arterial pressure are
also monitored. Comparison of the relative antagonist potency on
changes in arterial pressure and intra-urethral pressure provide insight
as to whether the alpha receptor subtype responsible for increasing
intra-urethral pressure is also present in the systemic vasculature.
25 According to this method, one is able to confirm the selectivity of
alphala adrenergic receptor antagonists that prevent the increase in
intra-urethral pressure to phenylephrine without any activity at the
vasculature.
In addition to the compounds specifically exemplified
above, the compounds shown below in Tables 1 and 2 are readily
prepared by one of ordinary skill in the art by following the teaching
described herein. Preparation of the bromides, RBr, are described in
European Patent Application EP 0600675-A to Kissei Corp. (Japan).
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O 1. HCI O
Il 2. RBr
,~, 3. R"COCI or ~
AcHN~O~ R"S02CI ~RHN' O~N_R
R' is R"CO or R"SO2
Vll
O O
RBr is~N> ~?
O H
~? ~?
O H
~ ~lX?
NO2 O NO2 H
CN o CN H
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TAE~I F 1
CH3SO2H~iN_ R
R is~X~ ~>
O H
~? ~?
O H
~ ~?
N~2 o N~2 H
m~? C H~,~?
CN o CN H
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TABI F 2
o
1~1 ~ ~N- R
R is ~[
O H
0 11
N~2 o~~ NO2 H
CH = ~?
C o CN H
While the foregoing specification teaches the principles of
the present invention, with exarnples provided for the purpose of
illustration, it will be understood that the practice of the invention
encompasses all of the usual variations, adaptations andlor modifications
as come within the scope of the following claims and their equivalents.
