Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
6-AZAINDOLE COMPOUNDS AS ANTAGONISTS OF
GONADOTROPIN RELEASING HORMONE
BACKGROUND OF THE INVENTION
The gonadotropin-releasing hormone (GnRH), also referred
to as luteinizing hormone-releasing hormone (LHRH), is a decapeptide
that plays a key role in human reproduction. The hormone is released
from the hypothalamus and acts on the pituitary gland to stimulate
the biosynthesis and secretion of luteinizing hormone (LH) and follicle-
stimulating hormone (FSH). LH released from the pituitary gland is
primarily responsible for the regulation of gonadal steroid production
in both sexes, whereas FSH regulates spermatogenesis in males and
follicular development in females. GnRH agonists and antagonists
have proven effective in the treatment of certain conditions which require
inhibition of LH/FSH release. In particular, GnRH-based therapies
have proven effective in the treatment of endometriosis, uterine fibroids,
polycystic ovarian disease, precocious puberty and several gonadal steroid-
dependent neoplasia, most notably cancers of the prostate, breast and
ovary. GnRH agonists and antagonists have also been utilized in various
assisted fertilization techniques and have been investigated as a potential
contraceptive in both men and women. They have also shown possible
utility in the treatment of pituitary gonadotrophe adenomas, sleep
disorders such as sleep apnea, irritable bowel syndrome, premenstrual
syndrome, benign prostatic hyperplasia, hirsutism, as an adjunct to
growth hormone therapy in growth hormone deficient children, and in
murine models of lupus. The compounds of the invention may also be
used in combination with bisphosphonates (bisphosphonic acids) and other
agents, such as growth hormone secretagogues, for the treatment and the
prevention of disturbances of calcium, phosphate and bone metabolism, in
particular, for the prevention of bone loss during therapy with the GnRH
antagonist, and in combination with estrogens, progesterones,
antiestrogens, antiprogestins and/or androgens for the prevention or
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treatment of bone loss or hypogonadal symptoms such as hot flashes
during therapy with the GnRH antagonist.
Additionally, a compound of the present invention may be
co-administered with a 5a-reductase 2 inhibitor, such as finasteride or
epristeride; a 5a-reductase 1 inhibitor such as 4,7b-dimethyl-4-aza-5a
cholestan-3-one, 3-oxo-4-aza-4,7b-dimethyl-16b-(4-chlorophenoxy)-5a-
androstane, and 3-oxo-4-aza-4,7b-dimethyl-16b-(phenoxy)-5a-androstane
as disclosed in WO 93/23420 and WO 95/11254; dual inhibitors of 5a-
reductase 1 and 5a-reductase 2 such as 3-oxo-4-aza-17b-(2,5-trifluoro-
methylphenyl-carbamoyl)-5a-androstane as disclosed in WO 95/0792'7;
antiandrogens such as flutamide, casodex and cyproterone acetate, and
alpha-1 blockers such as prazosin, terazosin, doxazosin, tamsulosin, and
alfuzosin.
Further, a compound of the present invention may be
used in combination with growth hormone, growth hormone releasing
hormone or growth hormone secretagogues, to delay puberty in growth
hormone deficient children, which will allow them to continue to gain
height before fusion of the epiphyses and cessation of growth at puberty.
Further, a compound of the present invention may be used
in combination or co-administered with a compound having luteinizing
hormone releasing activity such as a peptide or natural hormone or analog
thereof. Such peptide compounds include leuprorelin, gonadorelin,
buserelin, triptorelin, goserelin, nafarelin, histrelin, deslorelin, meterlin
and recirelin.
Additionally, a compound of the present invention may
be used as described in U.S. Patent No. 5,824,286 which discloses the
administration of peptide GnRH antagonists such as Antide and azaline
B to premenopausal women to enhance the readability of mammographic
film relative to a mammogram effected in the absence of the
administration.
Current GnRH antagonists are GnRH-like decapeptides
which are generally administered intravenously or subcutaneously
presumably because of negligible oral activity. These have amino
acid substitutions usually at positions one, two, three, six and ten.
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Non-peptide GnRH antagonists offer the possible
advantage of oral adminstration. Non-peptide GnRH antagonists have
been described in European Application 0 219 292 and in De, B. et al.,
J. Med. Chem., 32, 2036-2038 (1989), in WO 95/28405, WO 95/29900
and EP 0679642 all to Takeda Chemical Industries, Ltd.
Substituted indoles known in the art include those
described in the following patents and patent applications. US Patent
No. 5,030,640 discloses alpha-heterocyclic ethanol aminoalkyl indoles
which are potent I3-agonists. US Patent No. 4,544,663 discloses
indolamine derivatives which are allegedly useful as male anti-fertility
agents. WO 90/05'l21 discloses alpha-amino-indole-3-acetic acids useful
as anti-diabetic, anti-obesity and anti-atherosclerotic agents. French
patent 2,181,559 discloses indole derivatives with sedative, neuroleptic,
analgesic, hypotensive, antiserotonin and adrenolytic activity. Belgian
patent 879381 discloses 3-aminoalkyl-1H-indole-5-thioamide and
carboxamide derivatives as cardiovascular agents used to treat
hypertension, Raynaud's disease and migraine. U.S. Patent Nos.
5,756,507, 5,'780,43'7 and 5,849,764 also disclose substituted arylindoles
as non-peptide antagonists of GnRH.
SUMMARY OF THE INVENTION
The present invention relates to compounds which are
non-peptide antagonists of GnRH which can be used to treat a variety of
sex-hormone related conditions in men and women, to methods for their
preparation, and to methods and pharmaceutical compositions containing
said compounds for use in mammals.
Because of their activity as antagonists of the hormone
GnRH, the compounds of the present invention are useful to treat a
variety of sex-hormone related conditions in both men and women.
These conditions include endometriosis, uterine fibroids, polycystic
ovarian disease, hirsutism, precocious puberty, gonadal steroid-dependent
neoplasias such as cancers of the prostate, breast and ovary, gonadotrophe
pituitary adenomas, sleep apnea, irritable bowel syndrome, premenstrual
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syndrome and benign prostatic hypertophy. They are also useful as an
adjunct to treatment of growth hormone deficiency and short stature,
and for the treatment of systemic lupus erythematosis. Further, the
compounds of the invention may be useful in ai2 vitro fertilization and as
contraceptives. The compounds may also be useful in combination with
androgens, estrogens, progesterones, antiestrogens and antiprogestogens
for the treatment of endometriosis, fibroids and in contraception. They
may also be useful in combination with testosterone or other androgens
or antiprogestogens in men as a contraceptive. The compounds may also
be used in combination with an angiotensin-converting enzyme inhibitor
such as Enalapril or Captopril, an angiotensin II-receptor antagonist such
as Losartan or a renin inhibitor for the treatment of uterine fibroids.
Additionally, the compounds of the invention may also be used in
combination with bisphosphonates (bisphosphonic acids) and other
agents, for the treatment and the prevention of disturbances of calcium,
phosphate and bone metabolism, in particular, for the prevention of bone
loss during therapy with the GnRH antagonist, and in combination with
estrogens, progesterones and/or androgens for the prevention or treatment
of bone loss or hypogonadal symptoms such as hot flashes during therapy
with the GnRH antagonist.
Additionally, a compound of the present invention may be
co-administered with a 5a-reductase 2 inhibitor, such as finasteride or
epristeride; a 5a-reductase 1 inhibitor such as 4, 7b-dimethyl-4-aza-5a-
cholestan-3-one, 3-oxo-4-aza-4,7b-dimethyl-16b-(4-chlorophenoxy)-5a-
androstane, and 3-oxo-4-aza-4,7b-dimethyl-16b-(phenoxy)-5a-androstane
as disclosed in WO 93/23420 and WO 95/11254; dual inhibitors of 5a-
reductase 1 and 5a-reductase 2 such as 3-oxo-4-aza-17b-(2,5-trifluoro-
methylphenyl-carbamoyl)-5a-androstane as disclosed in WO 95/07927;
antiandrogens such as flutamide, casodex and cyproterone acetate, and
alpha-1 Mockers such as prazosin, terazosin, doxazosin, tamsulosin, and
alfuzosin.
Further, a compound of the present invention may be
used in combination with growth hormone, growth hormone releasing
hormone or growth hormone secretagogues, to delay puberty in growth
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hormone deficient children, which will allow them to continue to gain
height before fusion of the epiphyses and cessation of growth at puberty.
Further,.a compound of the present invention may be used
in combination or co-administered with a compound having luteinizing
hormone releasing activity such as a peptide or natural hormone or analog
thereof. Such peptide compounds include leuprorelin, gonadorelin,
buserelin, triptorelin, goserelin, nafarelin, histrelin, deslorelin, meterlin
and recirelin.
Additionally, a compound of the present invention may
be used as described in U.S. Patent No. 5,824,286 which discloses the
administration of peptide GnRH antagonists such as Antide and azaline
B to premenopausal women to enhance the readability of mammographic
film relative to a mammogram effected in the absence of the
administration.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to compounds of the general
formula
Rs R2
Rr1/s NWA)-R~
R~ ~~ ~CR9R9a)m~
R10a
N
N
Rs ~ ~ R3
Ro
R5 R4 (I)
wherein
A is C1-Cg alkyl, substituted C1-C6 alkyl, Cg-C7 cycloalkyl,
substituted C3-C7 cycloalkyl, C3-Cg alkenyl, substituted
C3-C6 alkenyl, C3-C6 alkynyl, substituted C3-C6 alkynyl,
C1-C6 alkoxy, or Cp-C5 alkyl-S(O)n-CO-C5 alkyl, CO-C5 alkyl-
O-Cp-C5 alkyl, CO-C5 alkyl-NRlg-CO-C5 alkyl where Rlg and
the CO-C5 alkyl can be joined to form a ring, or a single bond;
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RO is hydrogen, Cl-Cg alkyl, substituted Cl-C6 alkyl, wherein the
substituents are as defined below; aryl, substituted aryl,
aralkyl or substituted aralkyl, wherein the substituents are as
defined for Rg, R4 and R5;
Rl is
z
N w N
~N
~ R13 ~~~~Z R13 R15
W /~ R14 R R ~~'~ Z
R R 15 14 R15 R13 R14 R13
O
Z
~Z.~R15 Z~ ~ ~R14 ~ __
N ~ // ~ /~ ~ R11
~IJ\R14 ~IJ\R14 N ~I'N
R13 R13 R13 R19 R13 R14
O
Z Z
N N
// ~ ~ N N-R11
N N=N R1y N-N N-~ N=N
R1s R1s I R11
R 11 O
~N y~ ~R13 ~ ~ -R11
R13
~J R13 l ~ R13 ~~~iJ ~~~ R N
R~5\R14 ~~I\R14 R15 R14 R1 14 R19
/ \~ / NWN ~ ~ N jRl3
R ~ = R13 ~ _ ~ R13
/ 13 L/ ~J L~/'.~/ .~~J R R
R15 R14 R15 R 15 14
R15 R14 14
/ ~ N=I ~Z~ R14~~Z
i
R13 R14 ~~.N R13 ~N~
R15 N R14 R13
the nitrogen atoms contained in the Rl heteroaromatic rings may exist
either as drawn or, when chemically allowed, in their oxidized
(N-~O) state;
R2 is hydrogen, C1-Cg alkyl, substituted Cl-C6 alkyl, aralkyl,
substituted aralkyl, aryl, substituted aryl, alkyl -OR11,
C1-C6~NR11R12)~ Cl-C6~CONR11R12) or C(NR11R12)NH~
R2 and A taken together form a ring of 5-7 atoms;
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R3, R4 and R5 are independently hydrogen, C1-Cg alkyl, substituted
C1-C6 alkyl, C2-C6 alkenyl, substituted C2-C6 alkenyl, CN,
nitro, C1-C3 perfluoroalkyl, C1-C3 perfluoroalkoxy, aryl,
substituted aryl, aralkyl, substituted aralkyl, R110(CH2)p-,
R11C(O)O(CH2)p-> R110C(O)(CH2)p-~ -(CH2)pS(O)nRl7~
-(CH2)pC(O)NR11R12 or halogen; wherein R17 is hydrogen,
C1-C6 alkyl, C1-C3 perfluoroalkyl, aryl or substituted aryl;
R3 and R4 taken together form a carbocyclic ring of 3-7 carbon atoms or
a heterocyclic ring containing 1-3 heteroatoms selected from
N, O and S;
Rg is hydrogen, C1-C6 alkyl, substituted C1-C6 alkyl, aryl,
substituted aryl, C1-C3 perfluoroalkyl, CN, N02, halogen,
R110(CH2)p-, NR21C(O)R20, NR21C(O)NR2pR21 or
SOnR20;
R7 is hydrogen, C1-C6 alkyl, or substituted C1-Cg alkyl, unless X is
hydrogen or halogen, then R7 is absent;
Rg is C(O)OR20, C(O)NR2pR21, NR20R21~ C(O)R20~
NR21C(O)R20, NR21C(O)NR.20R21~ NR20S(O)2R21~
NR21S(O)2NR20R21~ OC(O)R20~ OC(O)NR2pR21~ OR20
SOnR2p, S(O)nNR2pR21, a heterocyclic ring or bicyclic
heterocyclic ring with from 1 to 4 heteroatoms selected from
N, O or S which can be optionally substituted by R3, R4 and
R5, C1-C6 alkyl or substituted
C1-Cg alkyl; or
R7 and Rg taken together form a heterocyclic ring containing one or more
heteroatoms selected from N, O or S which can be optionally
substituted by R3, R4 and R5;
Rg and Rga are independently hydrogen, C1-Cg alkyl, substituted C1-C6
alkyl; aryl or substituted aryl, aralkyl or substituted aralkyl
when m~0; or
O
Rg and Rga taken together form a carbocyclic ring of 3-7 atoms or II
when m~0;
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Rg and A taken together form a heterocyclic ring containing 3-7 carbon
atoms and one or more heteroatoms when m~0; or
Rlp and RlOa are independently hydrogen, C1-C6 alkyl, substituted
C1-C6 alkyl, aryl, substituted aryl, aralkyl or substituted
aralkyl; or
O
Rlp and RlOa taken together form a carbocyclic ring of 3-7 atoms or
Rg and Rlp taken together form a carbocyclic ring of 3-7 carbon atoms or
a heterocyclic ring containing one or more heteroatoms when
m~0; or
Rg and R2 taken together form a heterocyclic ring containing 3-7 carbon
atoms and one or more heteroatoms when m~0; or
Rlp and R2 taken together form a heterocyclic ring containing 3-7 carbon
atoms and one or more heteroatoms;
Rlp and A taken together form a heterocyclic ring containing 3-7 carbon
atoms and one or more heteroatoms; or
R11 and R12 are independently hydrogen , C1-C6 alkyl, substituted
C1-C6 alkyl, aryl, substituted aryl, aralkyl, substituted
aralkyl, a carbocyclic ring of 3-7 atoms or a substituted
carbocyclic ring containing 3- r atoms;
R11 and R12 taken together can form an optionally substituted ring of 3-7
atoms;
R13 is hydrogen, OH, NR7Rg, NR11S02(C1-C6 alkyl),
NR11S02(substituted C1-C6 alkyl), NR11S02(aryl),
NR11S02(substituted aryl), NR11S02(C1-C3 perfluoroalkyl);
S02NR11(C1-C6 alkyl), S02NR11(substituted C1-C6 alkyl),
S02NR11(aryl), S02NR11(substituted aryl), S02NR11(C1-C3
perfluoroalkyl); S02NR11(C(O)C1-C6 alkyl); S02NR11(C(O)-
substituted C1-Cg alkyl); S02NR11(C(O)-aryl);
S02NR11(C(O)-substituted aryl); S(O)n(C1-C6 alkyl); S(O)n
(substituted C1-Cg alkyl), S(O)n(aryl), S(O)n(substituted
aryl), C1-C3 perfluoroalkyl, C1-C3 perfluoroalkoxy, C1-C6
alkoxy, substituted C1-C6 alkoxy, COOH, halogen, N02 or
CN;
_ g _
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R14 and R15 are independently hydrogen, C1-C6 alkyl, substituted
C1-C6 alkyl, C2-C6 alkenyl, substituted C2-C6 alkenyl, CN,
nitro, C1-.C3 perfluoroalkyl, C1-C3 perfluoroalkoxy, aryl,
substituted aryl, aralkyl, substituted aralkyl, R110(CH2)p-,
R11C(O)O(CH2)p-, R110C(O)(CH2)p-, -(CH2)pS(O)nRl7~
-(CH2)pC(O)NR11R12 or halogen; wherein R17 is hydrogen,
C1-C6 alkyl, C1-C3 perfluoroalkyl, aryl or substituted aryl;
Rlg is hydrogen, C1-C6 alkyl, substituted C1-C6 alkyl, C(O)OR11,
C(O)NR11R12~ C(O)R11~ S(O)nRll~
Rlg is either the definition of R13 or R14>
R20 and R21 are independently hydrogen , C1-C6 alkyl, substituted
C1-C6 alkyl, aryl, substituted aryl, aralkyl, substituted
aralkyl, a carbocyclic ring of 3-7 atoms, a substituted
carbocyclic ring containing 3-'7 atoms, a heterocyclic ring or
bicyclic heterocyclic ring with from 1 to 4 heteroatoms selected
from N, O or S which can be optionally substituted by R3, R4
and R5, C1-C6-alkyl substituted by a heterocyclic ring or
bicyclic heterocyclic ring with from 1 to 4 heteroatoms selected
from N, O or S which can be optionally substituted by R3, R4
and R5;
R20 and R21 taken together can form an optionally substituted ring of 3-7
atoms;
X is N, O, S(O)n, C(O), (CR11R12)p, a single bond to Rg, C2-C6
alkenyl, substituted C2-Cg alkenyl,C2-Cg alkynyl, or
substituted C2-C6 alkynyl; when X is O, S(O)n, C(O), or
CR11R12 only Rg is possible;
Z is O, S or NR11;
m is 0-3;
n is 0-2;
p is 0-4; and
the alkyl, cycloalkyl, alkenyl and alkynyl substituents are
selected from C1-Cg alkyl, C3-C7 cycloalkyl, aryl, substituted
aryl, aralkyl, substituted aralkyl, hydroxy, oxo, cyano, C1-C6
alkoxy, fluoro, C(O)OR11 aryl C1-C3 alkoxy, substituted aryl
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C1-C3 alkoxy, and the aryl substituents are as defined for R3,
R4 and R5;
or a pharmaceutically acceptable addition salt and/or hydrate thereof, or
where applicable, a geometric or optical isomer or racemic mixture
thereof.
Preferred substituents when R20 and R21 are taken together
include 7-aza-bicyclo[2.2.1]heptane and 2-aza-bicyclo[2.2.2]
octane.
Unless otherwise stated or indicated, the following
definitions shall apply throughout the specification and claims.
When any variable (e.g., aryl, heterocycle, R1, etc.) occurs
more than one time in any constituent or in formula I, its definition on
each occurrence is independent of its definition at every other occurrence.
Also, combinations of substituents and/or variables are permissible only
if such combinations result in stable compounds.
The term "alkyl" is intended to include both branched-
and straight-chain saturated aliphatic hydrocarbon groups having the
specified number of carbon atoms, e.g., methyl (Me), ethyl (Et), propyl,
butyl, pentyl, hexyl, heptyl, octyl, nonanyl, decyl, undecyl, dodecyl, and
the isomers thereof such as isopropyl (i-Pr), isobutyl (i-Bu), sec-butyl
(s-Bu), tert-butyl (t-Bu), isopentane, isohexane, etc.
The term "aryl" includes phenyl and naphthyl. In a preferred
embodiment, aryl is phenyl.
The term "halogen" or "halo" is intended t.o include fluorine,
chlorine, bromine and iodine.
The term "heterocycle" or "heterocyclic ring" is defined by all
non-aromatic, heterocyclic rings of 3-'7 atoms containing 1-3 heteroatoms
selected from N, O, and S, such as oxirane, oxetane, tetrahydrofuran,
tetrahydropyran, pyrrolidine, piperidine, tetrahydropyridine, tetrahydro-
pyrimidine, tetrahydrothiophene, tetrahydrothiopyran, morpholine,
hydantoin, valerolactam, pyrrolidinone, and the like.
As used herein, the term "composition" is intended to
encompass a product comprising the specified ingredients in the specified
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amounts, as well as any product which results, directly or indirectly, from
combination of the specified ingredients in the specified amounts.
In addition, it is well known to those skilled in the art that
many of the foregoing heterocyclic groups can exist in more than one
tautomeric form. It is intended that all such tautomers be included within
the ambit of this invention.
The optical isomeric forms, that is mixtures of enantiomers,
e.g., racemates, or diastereomers as well as individual enantiomers or
diastereomers of the instant compound are included. These individual
enantiomers are commonly designated according to the optical rotation
they effect by the symbols (+) and (-), (L) and (D), (1) and (d) or
combinations thereof. These isomers may also be designated according
to their absolute spatial configuration by (S) and (R), which stands for
sinister and rectus, respectively.
The individual optical isomers may be prepared using
conventional resolution procedures, e.g., treatment with an appropriate
optically active acid, separating the diastereomers and then recovering
the desired isomer. In addition, the individual optical isomers may be
prepared by asymmetric synthesis.
Additionally, a given chemical formula or name shall
encompass pharmaceutically acceptable addition salts thereof and
solvates thereof, such as hydrates.
The compounds of the present invention, while effective
themselves, may be formulated and administered in the form of their
pharmaceutically acceptable addition salts for purposes of stability,
convenience of crystallization, increased solubility and other desirable
properties.
The compounds of the present invention may be
administered in the form of pharmaceutically acceptable salts. The term
"pharmaceutically acceptable salt" is intended to include all acceptable
salts. Examples of acid salts are hydrochloric, nitric, sulfuric, phosphoric,
formic, acetic, trifluoroacetic, propionic, malefic, succinic, malonic,
methanesulfonic, benzenesulfonic and the like which can be used as a
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dosage form for modifying the solubility or hydrolysis characteristics or
can be used in sustained release or prodrug formulations. Depending
on the particular functionality of the compound of the present invention,
pharmaceutically acceptable salts of the compounds of this invention
include those formed from cations such as sodium, potassium, aluminum,
calcium, lithium, magnesium, zinc, and from bases such as ammonia,
ethylenediamine, N-methyl-glutamine, lysine, arginine, ornithine, choline,
N,N'-dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine,
N-benzylphenethylamine, diethylamine, piperazine, tris(hydroxymethyl)
aminomethane, and tetramethylammonium hydroxide. These salts may
be prepared by standard procedures, e.g. by reacting a free acid with a
suitable organic or inorganic base, or alternatively by reacting a free base
with a suitable organic or inorganic acid.
Also, in the case of an acid (-COOH) or alcohol group
being present, pharmaceutically acceptable esters can be employed, e.g.
methyl, ethyl, butyl, acetate, maleate, pivaloyloxymethyl, and the like,
and those esters known in the art for modifying solubility or hydrolysis
characteristics for use as sustained release or prodrug formulations.
The compounds of the present invention may have chiral
centers other than those centers whose stereochemistry is depicted in
formula I, and therefore may occur as racemates, racemic mixtures and
as individual enantiomers or diastereomers, with all such isomeric
forms being included in the present invention as well as mixtures
thereof. 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 instant invention may form solvates with water
or common organic solvents. Such solvates are encompassed within
the scope of this invention.
The compounds of the invention are prepared according to
the following reaction schemes. All of the substituents are as defined
above unless indicated otherwise.
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Reaction Scheme A
R8
Pd(dppOCl2~CHzCIz
R~ ~. I (CR9Rya)~O~PG~ LiCI Na2C03,
+ ~ R/~o\Rtoa DMF, heat
NHz Z 2a Z = H
s 1 2b Z = Et3Si
2cZ=
~~ R3
Rs s Ra R
I8
R ~ ~. (CR9R9a m
R~ ~ Z
R~oRaoa ~ ~ R~oR~oa
Z and N ~ ~ ~PG~
R Fi Rs H (CR~R9a~~
3b Z = Et~Si
3cZ= 4aZ=H
4cZ=
Rs ~ R
3
Rs Ra /
Rs R4
A preferred method for the synthesis of the substituted
tryptamines described in this invention utilizes a palladium-catalyzed
cross coupling reaction as a key step as shown in Scheme A. This 6-
azaindole synthesis involves the reaction of a suitably functionalized
3-amino-4-iodopyridine (1) with substituted acetylenes such as 2 in
the presence of a base like sodium carbonate, lithium chloride, and a
palladium catalyst such as (dppf)PdCl~~ ~ CHaClp. The reaction is conducted
in an inert organic solvent such as dimethylformamide at elevated
temperatures, for instance at 100°C, and the reaction is conducted for
a
period of about 30 minutes to about 24 hours. A standard workup and
isolation affords the substituted isomeric indole derivatives 3 and 4, and
the isomer of general formula 3 is the preferred isomer. The acetylene
utilized in this reaction may be a terminal acetylene (2a) or be optionally
substituted on the terminal carbon atom with a substituent Z (2b, 2c).
The substituent abbreviated PG1 indicates an alcohol protecting group
such as a benzyl ether, tert-butyl ether or the like. The nature of the Z
substituent determines the distribution of the 6-azaindole isomers (3
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and 4) produced in the reaction. For example, if the substituent Z on the
acetylene is a hydrogen atom then the isomer 4a is the major product of
the reaction. When the substituent Z is chosen to be a substituted silyl
group such as trimethylsilyl, triethylsilyl (as shown), or the like, then
isomer 3b is formed almost exclusively. When Z is a substituted aryl
group, then both isomers 3c and 4c may be formed and the product
mixture is separated using chromatographic or crystallization techniques
to afford the individual isomers.
If the synthesis is conducted with a silyl-substituted
acetylene 2b to produce a silyl-substituted 6-azaindole 3b, then the silyl
group is next converted to an aryl or substituted aryl group of general
formula 3c using the reactions described later in Scheme E. The 2-
arylsubstituted 6-azaindole derivatives 3c formed either directly from
arylacetylenes (2c) as shown in Scheme A or from 2-trialkylsilyl-6-
azaindoles using the method of Scheme E are then further elaborated as
described below to produce the novel 6-azaindole derivatives described in
this invention.
Reaction Scheme B
R$ Ra Ra
10% Pd/C ~ t-BuCOCI,
R~~~ ~ Hz (50 psi), R~ ~ ~ Et.,O/THF R~~~ ~ O
N~ / NO MeOH ~ N/~NH2 Et~N, O1~C'~ N~~N~t-Bu
Rs z Rs Rs H
5 6 7
1 ) t-BuLi, R8 R8
TMEDA THF, ~ 24% HZSO~,
-78~C ~ R7 ~ ~ ~ O 100~C R7 ~ ~ i
2) lz, THF, N. ~ ~ ~ N. /
-78~C to RT 6 H t-Bu ~ NHz
8
Scheme B illustrates the preparation of substituted 3-
- 14 -
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amino-4-iodopyridines (1) which are utilized in the 6-azaindole synthesis
described in Scheme A. Substituted 3-nitropyridine derivatives such
as 5 are useful starting materials for the preparation of 3-amino-4-
iodopyridines (1). The 3-nitropyridines (5) bearing the desired
substituents can in turn be prepared by the nitration of a pyridine
derivative, by a nucleophilic aromatic substitution reaction from a
suitable halogenated nitropyridine or by other methods known in the
chemical literature. The nitro substituent of a 3-nitropyridine is readily
reduced to the required 3-amino group using a variety of methods such
as catalytic hydrogenation and the resulting 3-amino group can then serve
as a directing group for the subsequent introduction of an iodine at the 4
position of the pyridine. To facilitate the introduction of the iodine atom
the 3-amino group is first converted to a good ortho-directing substituent
such as a pivalamide (7). This is achieved by reacting the 3-amino-
pyridine 6 with pivaloyl chloride in the presence of an amine base like
triethylamine in a suitable inert solvent followed by a standard workup
and isolation. The resulting pivalamide 7 is then subjected to ortho-
lithiation by treatment with a strong or ganolithium base such as tert-
butyl lithium in the presence of a N,N,N',N'-tetramethylethylene-
diamine. The ortho-lithiation is conducted in an inert solvent such as
tetrahydrofuran at low temperature, typically -78°C, and the 4-
lithiated
derivative is the predominant regioisomer formed. Once the lithiation
reaction is complete the reaction mixture is then treated with an
iodinating reagent like iodine or iodine monochloride in a compatable
solvent such as tetrahydrofuran and then allowed to warm to room
temperature. Workup and product purification affords the 4-iodopyridine
derivative 8 which in the final step is converted to the substituted 3-
amino-4-iodopyridines of general formula 1 by removal of the ortho-
directing group. In the case illustrated in reaction Scheme B where a
pivaloyl group was chosen as the ortho-directing group it may be removed
by hydrolysis under acidic conditions such as treatment with sulfuric acid
at anelevated temperature.
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Reaction Scheme C
NH
Ph~O~CCl3
(CR~R9a)~OH CF3S03H > / 1 ) n-BuLi,
(CR9R9a)m O \ ~ THF, -78bC>
R~oR~oa CCI~-C6H12 j ~ 2 Et SiCI
R~oR~oa )
9 2a
/
(CR~R9a)m O
Et3Si' 2b Rio Raoa
(CRgR9a)~OH I \ X Pd(OAc}~, PPh~, (CR9R~a)n~OH
Rs / \/
R~oR~oa + ~~\ CuI, Et3N, > I \ ~ R~oR~oa
9 10 R4 R3 85hC Rs
~/~~R3 11
X = Br, I, OSOZCF3
NH
(CR9R~a)m~0 \
P~O~CCI3
CF3S03H R i \ R~oR~oa
> s
CCl -C H 2c
4 6 12 R4 R3
Acetylenic compounds of general structure 2 are prepared
using one of several methods depending upon the choice of the desired
substituents. When the substituents Rs, Roa, Rio and R~o~ are selected
to be hydrogen or lower alkyl groups, compounds of formula 2 may be
prepared from known acetylenic alcohols such as 3-butyn-1-ol, 4-pentyn-
2-0l or similar acetylenic alcohols reported in the chemical literature.
The conversion of acetylenic alcohols of general formula 10 to acetylene
derivatives of general formula 2 is shown in Scheme C. For clarity the
hydroxyl protecting group (PG1) illustrated in Scheme C is exemplified
as an O-benzyl ether. Thus, reaction of 10 with O-benzyl-2,2,2-trichloro-
acetimidate in the presence of a catalytic amount of a strong acid such as
trifluoromethanesulfonic acid and in a suitable inert organic solvent like
carbon tetrachloride at room temperature affords after 2 to 24 hours
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the protected acetylenic alcohol 2a. Compounds of formula 2a may in
turn be converted to acetylenes (2b) of general formula 2 wherein Z is a
trialkylsilyl group by.deprotonation of the acetylene with a base such as
n-butyllithium in an inert organic solvent like tetrahydrofuran followed
by reaction with a trialkylsilyl chloride such as triethylchlorosilane. The
deprotonation and silylation reactions are generally conducted at low
temperatures, for instance between about -78°C and room temperature,
and after standard workup and purification a silylacetylene of formula 2b
is obtained.
As previously stated, acetylenes of general formula 2c
wherein Z is an aryl or substituted aryl group, are also useful in the 6-
azaindole synthesis illustrated in Scheme A. Arylacetylenes 2c may be
prepared using a coupling reaction of cuprous acetylides derived from
acetylenic alcohols of formula 2a with various aryl halides or aryl triflates
(11). Such coupling reactions produce aryl acetylenes of general formula
12 as shown at the bottom of Scheme C. These reactions are generally
carried out in a basic organic solvent like triethylamine at elevated
temperatures, typically between about 60°C and about 120°C, and
the
coupling reaction is catalyzed by copper(I) salts such as cuprous iodide
and a palladium catalyst such as palladium acetate in combination with
triphenylphosphine. The hydroxyl group of the arylacetylenes of general
formula 12 can be protected with a suitable protecting group such as the
O-benzyl ether group shown in Scheme C, to afford an arylacetylene (2c) of
general formula 2 wherein Z is an aryl or substituted aryl group. It is also
recognized that in some cases it may be preferable to reverse the order of
the steps illustrated in Scheme C. For instance, acetylenic alcohols (7)
may be subjected to silylation or arylation prior to the hydroxyl group
protection step.
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Reaction Scheme D
NH
CR R OH Ph~O~CCI3
RO ( 9 gay CF3S03H > RO (CR R O \
9 9a)m~ LiAlH4, THF
O Rio Raoa
CC14-C~H i, >
12 R~oR~oa
13
/ 1) DMSO, (COC1),, /
HO (CR~R9a)m O \ ~ CH~CIZ, -50hC
> H (CRgRga~m O
R Boa 2) Et~N
14 O R~oR~oa
CBr4, PPh3, /
CHZCIZ, rt H (CR R ) O \ ~ (CR~R~a)m
9 9a m
R~oR~oa > ~ R~~oa
B ~Br 16 n-BuLi, THF, 2a
-78pC to OhC
5 Another useful approach for the preparation of acetylenic
compounds of general formula 2a employs an ethynylation reaction
sequence of aldehydes of general formula 16 as shown in Scheme D. The
aldehydes (16) used in the ethynylation sequence may be prepared using
various methods known in organic synthesis starting with hydroxyesters
10 of general formula 13, from protected hydroxyesters of formula 14, or from
alcohols related to the mono-hydroxyl protected diols of formula 15. The
choice of preferred starting material depends upon the nature of the
substituents Rs, Rsa, Rlo, and Rlo~ selected. Scheme D illustrates this
strategy begining with the generalized hydroxy ester 13. Protection of the
15 hydroxyl group of 13, for instance as the O-benzylether shown, affords a
protected hydroxy ester of formula 14. The ester group of compounds of
formula 14 can then be converted to an aldehyde of formula 16 either
directly using a reagent like diisobutylaluminum hydride in a solvent like
toluene, or through a two step process. In the two step process, reduction
of the ester group with a reagent such as lithium aluminum hydride in
tetrahydrofuran affords alcohols of formula 15 which are then subjected
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to reoxidation, for instance using a Swern-Moffatt oxidation, to afford the
desired aldehydes of formula 16.
The ethynylation of aldehydes of formula 16 is accomplished
in two steps. First, aldehydes (16) are reacted with carbon tetrabromide
and triphenylphosphine in an inert organic solvent like dichloromethane
to produce the dibromo olefins of formula 17. Next, the dibromo olefins
(17) are treated with two equivalents of a strong base such as
m-butyllithium in tetrahydrofuran at low temperature, for instance at
about -78°C. The strong base induces dehydrohalogenation and metal-
halogen exchange to afford lithium acetylides which upon quenching
and workup afford acetylenes of general formula 2a. Alternatively, the
intermediate lithium acetylides formed in the reaction may be treated
with a trialkylsilyl chloride, such as triethylchlorosilane, to afford
silylacetylenes of general formula 2b.
Reaction Scheme E
Rs Ra
R~~~' ~CR9R9a)~W PG1 R~ ' ~CR9R9a)~G~PG
/\ 1
N~ , RloRloa RloRloa
R H SiEt3 ~ R H i
ICI, AgBF;~, s
3b MeOH-TI-IF, OpC 17
R$
\ R~~~' ~CR9R9a)n~G~pG
17 + 1
R
R1o Rloa
N~~,
Rs ~ N \
(dpp~PdCl,~CH,CI,, Rs H I , ~J R3
1g toluene-EtOH 2M aq. Na,CO;, 3c
80pC Rs Ra
The conversion of 2-silyl-substituted 6-azaindoles of general
formula 3b to 2-aryl-substituted 6-azaindoles of general formula 3c may
be accomplished in two steps as shown in Scheme E. The first step is a
halodesilylation reaction which converts silyl-substituted 6-azaindoles
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of formula 3b into 2-halo-6-azaindoles of general formula 18. Scheme E
illustrates this process using iodine monochloride so that the product
obtained is a 2-iodoindole of general formula 18. Silver tetrafluoroborate
is also employed in this example to increase the reactivity of the
halogenating reagent. It is possible to effect the halodesilylation
reaction with other electrophilic halogenating reagents such as N
bromosuccinimide in dichloromethane which affords a 2-bromo-6-
azaindole derivative. Both 2-bromo and 2-iodo-6-azaindoles of formula
18 are useful in the subsequent step.
The second step is a palladium-catalyzed cross coupling
reaction of the 2-halo-6-azaindole 18 with a suitable aryl or substituted
aryl organometallic reagent 19. Scheme E illustrates this process with
an aryl or substituted arylboronic acid as the organometallic reagent,
however, other organometallic reagents known to participate in
palladium-catalyzed cross-coupling reactions such as arylboronic esters
or arylstannanes may also be employed. In the example, a 2-iodo-6-
azaindole of general formula 18 is coupled with a generalized boronic
acid (19) using a catalyst such as [l,1'-bis(diphenylphosphino)ferrocene]
dichloropalladium(II) complex with dichloromethane (shown), tetrakis
(triphenylphosphine)-palladium(0) or the like. The reaction is usually
conducted at temperatures between room temperature and about 100°C,
for instance at about 80°C. This palladium catalyzed cross-coupling
reaction may be effected using various combinations of palladium
catalysts and solvent compositions known in organic chemistry, and
the selection of the conditions is made depending upon the type of
organometallic reagent (19) used and the identity of the substituent
groups in the two starting materials. When the organometallic reagent is
a boronic acid or boronate ester then a preferred solvent mixture consists
of toluene, ethanol and an aqueous solution of a base like cesium or
sodium carbonate. If instead the organometallic reagent 19 is an
arylstannane, then no additional base is required, and a polar aprotic
solvent such as tetrahydrofuran or dimethylformamide is employed.
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Reaction Scheme F
Ra Ra
R~ ~ (CR~R9a)~W R ~~ (CR9R9a)n, W
Protect
N / ~ Rio R~oa 6-azaindole ( Rio R~oa
Rs H ~ \ N~
R3 or introduce R6 I R
v R~ SUbStItUent PGz
3c Rs Ra 19 Rs Ra
a
Deprotect PPh~, DEAD
alcohol R~ ~ (CR9R~a)n~GH Zn(N3),~2pyr,
R~oR~oa imidazole, CH,CI'
rt, 1-24 h - _
R6 PGZ ~/ ~J Rs
20 Rs RQ
Ra Ra
CR R ~N3 ~ CR R NH
R~ . ~ 9 9a)m 10% Pd~C, H,, R~ ~ 9 9a)m
N /' ~ ~ R~oR~oa EtOH, rt 1-12 h ~ ~ ~ R~oR~oa
N \ s ~' \
R6 PGZ ~~ ~~J R3 Ra P R3
21 Rsv R4 22
The next stage of the synthesis of the novel 6-azaindole
derivatives is illustrated in Scheme F. This sequence of reactions begins
with protection of the 6-azaindole with an amine protecting group (PGp)
to afford compounds of general formula 20. The protection step is required
to avoid competing side rections of the 2-aryltryptophol of formula 21
(where PG2 is H) in the later conversion of compounds of formula 21 to
compounds of formula 22. The indole protection is followed by removal
of the hydroxyl protecting group (PGl) from the side chain at the C-3
position of the 6-azaindole ring to afford compounds of general formula
21. Finally, the hydroxyl group of 21 is converted to a primary amine of
general formula 23 which is then further functionalized as shown below
in the following schemes. The choice of an appropriate amine protecting
group (PG2) for the 6-azaindole is determined primarily by which protect-
ing group (PGi) is present on the hydroxyl group in the C-3 sidechain,
and by consideration of the chemical stability of the amine protecting
group (PG1) required in the remaining steps of the synthesis. When
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the hydroxyl protecting group (PG1) is an0-benzyl ether as illustrated
previously in Schemes C and D, the 6-azaindole may be protected as
a carbamate derivative such as a tent-butylcarbamate (BOC). In this
case, the BOC-protected 6-azaindole is stable under the hydrogenolysis
conditions which are used to remove the O-benzyl ether and it may be
conveniently removed at the end of the synthesis using acidic conditions.
If it is desired to synthesize compounds of formula (I) wherein Ro is alkyl,
substituted alkyl or the like, then it is possible to introduce that
substituent at this point and the use of a protecting group and its
subsequent removal is not required.
An alcohol of general formula 21 may be converted to a
primary amine of general formula 23 using a variety of methods known
in the literature of organic chemistry . The bottom of Scheme F illustrates
a process where the alcohol 21 is first converted to an azide of general
formula 22, followed by reduction to afford the amine derivative 23. The
synthesis of an azide of general formula 22 from alcohols like 21 is best
accomplished by performing a Mitsunobu reaction in the presence of an
appropriate azide source such as diphenylphosphoryl azide or zinc azide
pyridine complex. Scheme F illustrates the reaction of alcohol 21 with
triphenylphosphine, diethylazodicarboxylate, zinc azide pyridine complex
and a proton source such as imidazole in an inert solvent like methylene
chloride or tetrahydrofuran. The reaction is usually conducted at room
temperature for periods between 1-24 hours, typically overnight or about
15 hours, and affords the azide of general formula 22 in good yield.
Finally, an azide of formula 22 may then be reduced to an amine of
formula 23 using one of several methods common in organic synthesis.
One preferred method is catalytic hydrogenation in a solvent like
methanol or ethanol in the presence of a catalyst such as 10% palladium
on carbon. Alternatively, azides like 22 may be reacted with triphenyl-
phosphine to form an iminophosphorane which upon hydrolysis with
water affords the amine of formula 23 and triphenylphophine oxide.
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Reaction Scheme G
HO~(AjR~
O 23
R
EDC, HOBt, I $ R2
R7~~. ~CR9R9a)n, NHZ NMM, CH,CI, R~~ (CR9R9a)n,
R~
Rio R~oa
R~oRtoa O
w i
Ro J s
22 Ro ~~V~ R X~(A,R~ ~ N ~ ~ R
Rs Ra O 25 24 Rs Ra
Et3N, CH,CI,
The final stage of the synthesis of the novel 6-azaindole
derivatives (I) involves elaboration of the sidechain at the C-3 position of
the 6-azaindole core. One method for the completion of the synthesis is
illustrated in Scheme G. As shown, the 2-aryltryptamine (23) may be
condensed with a carboxylic acid of type 24 using the coupling reagent
1-(3-dimethylamino-propyl)-3-ethylcarbodiimide hydrochloride (EDC),
1,3-dicyclohexyl-carbodiimide (DCC) or the like with or without 1-
hydroxybenzotriazole (HOBt) and a tertiary amine base such as N-
methylmorpholine (NMM), triethylamine or the like in an inert organic
solvent such as methylene chloride, chloroform, dimethylformamide, or
mixtures thereof at or near room temperature for a period of 3-24 hours
to provide the corresponding amide derivative (25). Alternatively, 2-
aryltryptamine 23 can be treated with an active ester or acid chloride
of formula 26 in an inert organic solvent such as methylene chloride,
chloroform, tetrahydrofuran, diethyl ether, or the like and a tertiary
amine base such as triethylamine, diisopropylethylamine, pyridine or
the like at a temperature of 0°-25°C for 30 minutes to 4 hours
to give
compound 25.
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Reaction Scheme H
R Rz R$ R2
R~ ~. ~CR9R9am~N~~A~R, R~~ ~ ~CR9R9a)n~N~~A~R
1
N / I R~oR~oa O BHP, THF ~ \ I R~oRtoa
Rs N I ~ or ~ N
R3 LiAIH~, TiF Rs Ro I ~ ~J Rs
24 R~ ~ 26 R .~~R4
As shown in reaction Scheme H, the amide carbonyl of 25
can be reduced by treatment with borane, lithium aluminum hydride,
or equivalent hydride sources in an inert organic solvent such as
tetrahydrofuran, diethyl ether, 1,4-dioxane or the like at about 25°C
to
about 100°C, preferably about 65°C, for a period of 1-8 hours to
give the
corresponding amine 27.
Reaction Scheme I
R Fi Re Rz
R~ - (CR9R9a)n~N~R p 27 R~~~ (CR9R9a)n~Ny ~R1
z ~A~_R~ ~ /\ A
N /' N I \ Rio R~oa > N / I I Rio R~oa
Rs I ~ ~ R3 TFA, 3 ~1 sieves Rs N I \ R3
22 Ro R~'~~~ NaCNBH~, MeOH 28 Ro R v~~R
5 4
As shown in reaction Scheme I, the 2-aryltryptamine 23
can be modified by treatment with an aldehyde or ketone of type 28 in
the presence of a weak acid such as trifluoroacetic acid (TFA), acetic acid
or the like, with or without a dessicant such as 3A molecular sieves or
magnesium sulfate, and a hydride source such as sodium borohydride or
sodium cyanoborohydride, in an inert organic solvent such as methanol,
ethanol, isopropanol, tetrahydrofuran, dichloromethane, chloroform, or
mixtures thereof at a temperature of about 0° to about 25°C for
a period
of 1-12 hours to give the corresponding secondary or tertiary amine
derivative 29.
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Reaction Scheme J
OzN N02
R~~~ OR9R9a)n~NH2
N ~ \ R~oR~oa ~ S02CI
Rs I 1
I ~ R3 2,4,6-collidine,
22 ~ ~~'~~R CH,CI,
4
OZN / NOZ
R$ O ~~~ Re
I I
R ~ . ~CR9R9a)n, NH 1. PPh3, DEAD, R~ ~. ~CR9R9a n, NyA~R~
benzene
N /' ~ N ~ \ Rto R~oa HOyAj R~ 3~ ~ N ~ \ Rio R~oa
I I ~ R3 > Rs ~ I ~ R
29 R° R ~%~~~ 2. n-propylamine 3~ R° R
5 R4
As shown in reaction Scheme J, the tryptamine 23 can be
5 modified using the Fukuyama modification of the Mitsunobu reaction
(Fukuyama, T.; Jow, C.-K.; Cheung, M. Tetrahedro~a Lett. 1995, 36, 6373-
'74). The tryptamine 23 may be reacted with an arylsufonyl chloride such
as 2-nitrobenzene-sulfonyl chloride, 4-nitrobenzenesulfonyl chloride or
2,4-dinitrobenzene-sulfonyl chloride and a hindered amine base such as
2,4,6-collidine, 2,6-lutidine or the like in an inert organic solvent such as
methylene chloride to provide the corresponding sulfonamide 30. The
sulfonamides can be further modified by reaction with an alcohol of type
31 in the presence of triphenylphosphine and an activating agent such
as diethylazodicarboxylate (DEAD), diisopropylazodicaboxylate or the like
in an inert organic solvent such as benzene, toluene, tetrahydrofuran or
mixtures thereof to give the dialkylsulfonamide adduct. Removal of a
dinitrobenzenesulfonyl group is accomplished by treatment with a
nucleophilic amine such as n-propylamine or the like in an inert organic
solvent such as methylene chloride to give secondary amines of type 32.
When a mono-nitrobenzenesulfonyl derivative is employed, the removal of
the sulfonamide is accomplished with a more nucleophilic reagent such as
thiophenol or mercaptoacetic acid in combination with lithium hydroxide
in DMF.
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Reaction Scheme K
Rs
I
Ri ~- ~CR9R9a)~OH OZN / NOZ 1. PPh~, DEAD,
\ I benzene
N\/, ~ ~ Rio R~oa
R6 N ~ + O OS \ 2. n-propylamine
I
J R3 HN~~A~ R~ 32 3. Remove PGz
20 Rs Ra
H
R7 ~- OR9R9a)~NyA~R1
N ., ~ _ R/~o\R~oa
Ra
31 R6 Ro
Rs R4
Reaction Scheme K illustrates a method that is
complimentary to reaction Scheme J for completing the synthesis of the
novel compounds of formula (I). Scheme K also employs the Fukuyama
modification of the Mitsunobu reaction similar to that illustrated in
reaction Scheme J. However in this instance, the alcohol partner
employed is a 2-aryltryptophol of general formula 21 which has been
decribed previously in reaction Scheme F. The 2-aryltryptophol (21)
is reacted with a substituted sulfonamide of general formula 33,
triphenylphosphine and diethylazodicarboxylate in a suitable inert
organic solvent such as benzene, tetrahydrofuran, 1,4-dioxane or the like.
The reaction is generally conducted at room temperature for a period of 2
to 24 hours, typically overnight or for about 12-16 hours. The product is
an N,N-disubstituted sulfonamide which is then separately subjected to
reaction with a base such as v-propylamine which removes the
sulfonamide substituent and furnishes a secondary amine related to
formula 32. The sulfonamides of formula 33 employed are readily
obtained from a primary amine and either 2-nitrobenzenesulfonyl
chloride, 4-nitrobenzenesulfonyl chloride or 2,4-dinitrobenzenesulfonyl
chloride (as shown) in the presence of a hindered amine base such as
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2,4,6-collidine, 2,6-lutidine or the like in an inert organic solvent such as
methylene chloride. The final stage of the synthesis requires removal
of the protecting group on the 6-azaindole nitrogen atom (PG2) which
produces a compound of general formula 32 wherein Ro is a hydrogen
atom. It will be recognized by individuals skilled in the art of organic
synthesis that a preference for utilizing either the synthetic sequences
outlined in reaction Schemes J or K will be determined by the
substituents selected to be present in the compounds of formula (I).
The compounds of the present invention are useful in
the treatment of various sex-hormone related conditions in men and
women. This utility is manifested in their ability to act as antagonists
of the neuropeptide hormone GnRH as demonstrated by activity in the
following in vitro assays.
Rat pituitary GnRH receptor binding assay:
Crude plasma membranes prepared from rat pituitary
tissues were incubated in a Tris.HCl buffer (50 mM, PH. 7.5) containing
bovine serum albumin (.1%), [I-125]D-t-Bu-Serb-Pro9-ethyl amide-GnRH,
and the desired concentration of a test compound. The assay mixtures
were incubated at 4°C for 90-120 minutes followed by rapid filtration
and repeated washings through a glass fiber filter. The radioactivity
of membrane bound radioligands was determined in a gamma-counter.
From this data, the IC50 of the radioligand binding to GnRH receptors
in the presence of test compound was estimated.
Inhibition of LH release assay:
Active compounds from the GnRH receptor binding assay
were further evaluated with an i~2 vitro LH release assay to confirm their
antagonist activity (blocking GnRH-induced LH release).
1. Sample Preparation
The compounds to be assayed were dissolved and diluted in
DMSO. The final concentration of DMSO in the incubation medium was
0.5%.
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2. Assay
The Wistar male rats (150-200 grams) were obtained from
Charles River Laboratories (Wilmington, MA). Rats were maintained
at a constant temperature (25°C) on a 12-hr light, 12-hr dark cycle.
Rat
chow and water were available ad libitum. The animals were sacrificed
by decapitation and pituitary glands were aseptically removed and placed
in Hank's Balanced Salt Solution (HBSS) in a 50-mL polypropylene
centrifuge tube. The collection tube was centrifuged for 5 min at 250 x g,
and HBSS was removed by aspiration. Pituitary glands were transferred
to a disposable petri plate and minced with a scalpel. The minced tissue
was then transferred to a 50-mL disposable centrifuge tube by suspending
the tissue fragments in three successive 10-mL aliquots of HBSS contain-
ing 0.2% collagenase and 0.2% hyaluronidase. The cell dispersion was
carried out in a water bath at 37°C with gentle stirring for 30 min. At
the
end of the incubation, the cells were aspirated 20 to 30 times with a pipet
and the undigested pituitary fragments were allowed to settle for 3 to 5
min. The suspended cells were removed by aspiration, and then subjected
to a 1200 x g centrifugation for 5 min. The cells were then resuspended
in Culture medium. The undigested pituitary fragments were treated
with 30 mL aliquots of the digestion enzymes as above for a total of 3
digestions with the collagenase/hyaluronidase mixture. The resulting cell
suspensions were pooled, counted and diluted to a concentration of 3 x 105
cells/ml, and 1.0 ml of this suspension was placed in each well of a 24-well
tray (Costar, Cambridge, MA): Cells were maintained in a humidified 5%
C02-95% air atmosphere at. 37°C for 3 to 4 days. The culture
medium
consisted of DMEM containing 0.37% NaHC03, 10% horse serum, 2.5%
fetal bovine serum, 1% non-essential amino acids, 1% glutamine, and 0.1%
gentamycin. On the day of an experiment, cells were washed three times
1 1/2 hrs prior to and two more times immediately before the start of the
experiment with DMEM containing 0.37% NaHC03, 10% horse serum,
2.5% fetal bovine serum, 1% non-essential amino acids(100X), 1%
glutamine(100X), 1% Penicillin/Streptomycin(10,000 Units of Penicillin
and 10,000 micrograms of Streptomycin per ml), and 25 mM HEPES, pH
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7.4. LH release was initiated by adding 1 ml of fresh medium containing
test compounds in the presence of 2 nM GnRH to each well in duplicate.
Incubation was carried out at 37°C for 3 hr. After incubation,
medium
was removed and centrifuged at 2,000 x g for 15 min to remove any
cellular material. The supernatant fluid was removed and assayed for LH
content with a double antibody RIA procedure using materials obtained
from Dr. A. F. Parlow (Harbor-UCLA Medical Center, Torrance, CA).
The compounds of formula I are useful in a number of areas
affected by GnRH. They may be useful in sex-hormone related conditions,
sex-hormone dependent cancers, benign prostatic hypertrophy or myoma
of the uterus. Sex-hormone dependent cancers which may benefit from
the administration of the compounds of this invention include prostatic
cancer, uterine cancer, breast cancer and pituitary gonadotrophe
adenomas. Other sex-hormone dependent conditions which may benefit
from the administration of the compounds of this invention include
endometriosis, polycystic ovarian disease, uterine fibroids and precocious
puberty. The compounds may also be used in combination with an
angiotensin-converting enzyme inhibitor such as Enalapril or Captopril,
an angiotensin II-receptor antagonist such as Losartan or a renin
inhibitor for the treatment of uterine fibroids.
The compounds of the invention may also be useful for
controlling pregnancy, as a contraceptive in both men and women, for
in vitro fertilization, in the treatment of premenstrual syndrome, in the
treatment of lupus erythematosis, in the treatment of hirsutism, in the
treatment of irritable bowel syndrome and for the treatment of sleep
disorders such as sleep apnea.
A further use of the compounds of this invention is as
an adjunct to growth hormone therapy in growth hormone deficient
children. The compounds may be administered with growth hormone
or a compound which increases the endogenous production or release
of growth hormone. Certain compounds have been developed which
stimulate the release of endogenous growth hormone. Peptides which
are known to stimulate the release of endogenous growth hormone
include growth hormone releasing hormone, the growth hormone
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releasing peptides GHRP-6 and GHRP-1 (described in U.S. Patent No.
4,411,890, PCT Patent Pub. No. WO 89/07110, and PCT Patent Pub.
No. WO 89/07111) and GHRP-2 (described in PCT Patent Pub. No.
WO 93/04081), as well as hexarelin (J. Endocrinol Invest., 15(Suppl 4),
45 (1992)). Other compounds which stimulate the release of endogenous
growth hormone are disclosed, for example, in the following: U.S. Patent
No. 3,239,345; U.S. Patent No. 4,036,979; U.S. Patent No. 4,411,890; U.S.
Patent No. 5,206,235; U.S. Patent No. 5,283,241; U.S. Patent No.
5,284,841; U.S. Patent No. 5,310,737; U.S. Patent No. 5,317,017; U.S.
Patent No. 5,374,721; U.S. Patent No. 5,430,144; U.S. Patent No.
5,434,261; U.S. Patent No. 5,438,136; EPO Patent Pub. No. 0,144,230;
EPO Patent Pub. No. 0,513,974; PCT Patent Pub. No. WO 94/07486; PCT
Patent Pub. No. WO 94/08583; PCT Patent Pub. No. WO 94/11012; PCT
Patent Pub. No. WO 94/13696; PCT Patent Pub. No. WO 94/19367; PCT
Patent Pub. No. WO 95/03289; PCT Patent Pub. No. WO 95/03290; PCT
Patent Pub. No. WO 95/09633; PCT Patent Pub. No. WO 95/11029; PCT
Patent Pub. No. WO 95/12598; PCT Patent Pub. No. WO 95/13069; PCT
Patent Pub. No. WO 95/14666; PCT Patent Pub. No. WO 95/16675; PCT
Patent Pub. No. WO 95/16692; PCT Patent Pub. No. WO 95/17422; PCT
Patent Pub. No. WO 95/17423; Science, 260, 1640-1643 (June 11, 1993);
Ann. Rep. Med. Chem., 28, 177-186 (1993); Bioorg. Med. Chem. Ltrs.,
4(22), 2709-2714 (1994); and Proc. Natl. Acad. Sci. USA 92, 7001-7005
(July 1995).
Representative preferred growth hormone secretagoues
employed in the present combination include the following:
1) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(1H-indol-3-yl)ethyl]-2-amino-2-methyl-
propanamide;
2) N-[1(R)-[(1,2-Dihydro-1-methanecarbonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(1H-indol-3-yl)ethyl]-2-amino-2-methyl-
propanamide;
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3) N-[1(R)-[(1,2-Dihydro-1-benzenesulfonylspiro[3H-indole-3,4'-piperidin]-
1'-yl)carbonyl]-2-(1H-indol-3-yl)ethyl]-2-amino-2-methyl-propanamide;
4) N-[1(R)-[(3,4-Dihydro-spiro[2H-1-benzopyran-2,4'-piperidin]-1'-yl)
carbonyl]-2-(1H-indol-3-yl)ethyl]-2-amino-2-methylpropanamide;
5) N-[1(R)-[(2-Acetyl-1,2,3,4-tetrahydrospiro[isoquinolin-4,4'-piperidin]-1'-
yl)carbonyl]-2-(indol-3-yl)ethyl]-2-amino-2-methyl-propanamide;
6) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(phenylmethyloxy)ethyl]-2-amino-2-
methylpropanamide;
7) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(phenylmethyloxy)ethyl]-2-amino-2-
methylpropanamide methanesulfonate;
8) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(2', 6'-difluorophenylmethyloxy)ethyl]-2-amino-
2-methylpropanamide;
9) N-[1(R)-[(1,2-Dihydro-1-methanesulfonyl-5-fluorospiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(phenylmethyloxy)ethyl]-2-amino-2-
methylpropanamide;
10) N-[1(S)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl) carbonyl]-2-(phenylmethylthio)ethyl]-2-amino-2-
methylpropanamide;
11) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-3-phenylpropyl]-2-amino-2-methyl-propanamide;
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12) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-3-cyclohexylpropyl]-2-amino-2-methyl-
propanamide;
13) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-4-phenylbutyl]-2-amino-2-methyl-propanamide;
14) N-[1(R)-[(1,2-Dihydro-1-methanesulfonylspiro(3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(5-fluoro-1H-indol-3-yl)ethyl]-2-amino-2-
methylpropanamide;
15) N-[1(R)-[(1,2-Dihydro-1-methanesulfonyl-5-fluorospiro[3H-indole-3,4'-
piperidin]-1'-yl)carbonyl]-2-(5-fluoro-1H-indol-3-yl)ethyl]-2-amino-2-
methylpropanamide;
16) N-[1(R)-[(1,2-Dihydro-1-(2-ethoxycarbonyl)methylsulfonylspiro-[3H-
indole-3,4'-piperidin]-1'-yl)carbonyl]-2-(1H-indol-3-yl)ethyl]-2-amino-2-
methylpropanamide;
17) N-[1(R)-[(1,2-Dihydro-1,1-dioxospiro[3H-benzothiophene-3,4'-
piperidin]-1'-yl)carbonyl]-2-(phenylmethyloxy)ethyl]-2-amino-2-
methylpropanamide;
and pharmaceutically acceptable salts thereof.
The compounds of the invention may also be used in
combination with bisphosphonates (bisphosphonic acids) and other
agents, such as growth hormone secretagogues, for the treatment and the
prevention of disturbances of calcium, phosphate and bone metabolism, in
particular, for the prevention of bone loss during therapy with the GnRH
antagonist, and in combination with estrogens, progesterones and or
androgens for the prevention or treatment of bone loss or hypogonadal
symptoms such as hot flashes during therapy with the GnRH antagonist.
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Bisphosphonates (bisphosphonic acids) are known to inhibit
bone resorption and are useful for the treatment of bone lithiasis as
disclosed in U.S. Patent 4,621,077 to Rosini, et al.
The literature discloses a variety of bisphosphonic acids
which are useful in the treatment and prevention of diseases involving
bone resorption. Representative examples may be found in the following:
U.S. Patent No. 3,251,907; U.S. Patent No. 3,422,137; U.S. Patent No.
3,584,125; U.S. Patent No. 3,940,436; U.S. Patent No. 3,944,599; U.S.
Patent No. 3,962,432; U.S. Patent No. 4,054,598; U.S. Patent No.
4,267,108; U.S. Patent No. 4,327,039; U.S. Patent No. 4,407,761; U.S.
Patent No. 4,578,376; U.S. Patent No. 4,621,077; U.S. Patent No.
4,624,947; U.S. Patent No. 4,746,654; U.S. Patent No. 4,761,406; U.S.
Patent No. 4,922,00'7; U.S. Patent No. 4,942,157; U.S. Patent No.
5,227,506; U.S. Patent No. 5,270,365; EPO Patent Pub. No. 0,252,504; and
J. Ors. Chem., 36, 3843 (1971).
The preparation of bisphosphonic acids and halo-
bisphosphonic acids is well known in the art. Representative examples
may be found in the above mentioned references which disclose the
compounds as being useful for the treatment of disturbances of calcium
or phosphate metabolism, in particular, as inhibitors of bone resorption.
Preferred bisphosphonates are selected from the group of the
following compounds: alendronic acid, etidrononic acid, clodronic acid.
pamidronic acid, tiludronic acid, risedronic acid, 6-amino-1-hydroxy-
hexylidene-bisphosphonic acid, and 1-hydroxy-3(methylpentylamino)-
propylidene-bisphosphonic acid; or any pharmaceutically acceptable salt
thereof. A particularly preferred bisphosphonate is alendronic acid
(alendronate), or a pharmaceutically acceptable salt thereof. An
especially preferred bisphosphonate is alendronate sodium, including
alendronate sodium trihydrate. Alendronate sodium has received
regulatory approval for marketing in the United States under the
trademark FOSAMAX~.
Additionally, a compound of the present invention may be
co-administered with a 5a-reductase 2 inhibitor, such as finasteride or
epristeride; a 5a-reductase 1 inhibitor such as 4,7(3-dimethyl-4-aza-5a-
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cholestan-3-one, 3-oxo-4-aza-4,7(3-dimethyl-16(3-(4-chlorophenoxy)-5a-
androstane, and 3-oxo-4-aza-4,7(3-dimethyl-16(3-(phenoxy)-5a-androstane
as disclosed in WO 93/23420 and WO 95/11254; dual inhibitors of 5a-
reductase 1 and 5a-reductase 2 such as 3-oxo-4-aza-17(3-(2,5-trifluoro-
ethylphenyl-carbamoyl)-5a-androstane as disclosed in WO 95/07927;
antiandrogens such as flutamide, casodex and cyproterone acetate, and
alpha-1 blockers such as prazosin, terazosin, doxazosin, tamsulosin, and
alfuzosin.
Further, a compound of the present invention may be used
in combination with growth hormone, growth hormone releasing hormone
or growth hormone secretagogues, to delay puberty in growth hormone
deficient children, which will allow them to continue to gain height before
fusion of the epiphyses and cessation of growth at puberty. Further, a
compound of the present invention may be used in combination or co-
administered with a compound having luteinizing hormone releasing
activity such as a peptide or natural hormone or analog thereof. Such
peptide compounds include leuprorelin, gonadorelin, buserelin, triptorelin,
goserelin, nafarelin, histrelin, deslorelin, meterlin and recirelin.
For combination treatment with more than one active agent,
where the active agents are in separate dosage formulations, the active
agents may be administered separately or in conjunction. In addition,
the administration of one element may be prior to, concurrent to, or
subsequent to the administration of the other agent.
The pharmaceutical compositions containing the active
ingredient may be in a form suitable for oral use, for example, as tablets;
troches, lozenges, aqueous or oily suspensions, dispersible powders or
granules, emulsions, hard or soft capsules, or syrups or elixirs.
Compositions intended for oral use may be prepared according to
any method known to the art for the manufacture of pharmaceutical
compositions and such compositions may contain one or more agents
selected from the group consisting of sweetening agents, flavoring
agents, coloring agents and preserving agents in order to provide
pharmaceutically elegant and palatable preparations. Tablets contain
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the active ingredient in admixture with non-toxic pharmaceutically
acceptable excipients which are suitable for the manufacture of tablets.
These excipients maybe for example, inert diluents, such as calcium
carbonate, sodium carbonate, lactose, calcium phosphate or sodium
phosphate; granulating and disintegrating agents, for example, corn
starch, or alginic acid; binding agents, for example starch, gelatin or
acacia, and lubricating agents, for example, magnesium stearate, stearic
acid or talc. The tablets may be uncoated or they may be coated by known
techniques to delay disintegration and absorption in the gastrointestinal
tract and thereby provide a sustained action over a longer period. For
example, a time delay material such as glyceryl monostearate or glyceryl
distearate may be employed. They may also be coated by the technique
described in the U.S. Patent 4,256,108; 4,166,452; and 4,265,874 to form
osmotic therapeutic tablets for control release.
Formulations for oral use may also be presented as hard
gelatin capsules wherein the active ingredient is mixed with an inert solid
diluent, for example, calcium carbonate, calcium phosphate or kaolin, or
as soft gelatin capsules wherein the active ingredient is mixed with water
or an oil medium, for example peanut oil, liquid paraffin, or olive oil.
Aqueous suspensions contain the active material in
admixture with excipients suitable for the manufacture of aqueous
suspensions. Such excipients are suspending agents, for example sodium
carboxymethylcellulose, methylcellulose, hydroxypropylmethyl-cellulose,
sodium alginate, polyvinyl-pyrrolidone, gum tr agacanth and gum acacia;
dispersing or wetting agents may be a naturally-occurring phosphatide,
for example lecithin, or condensation products of an alkylene oxide with
fatty acids, for example polyoxyethylene stearate, or condensation
products of ethylene oxide with long chain aliphatic alcohols, for example
heptadecaethylene-oxycetanol, or condensation products of ethylene oxide
with partial esters derived from fatty acids and a hexitol such as
polyoxyethylene sorbitol monooleate, or condensation products of ethylene
oxide with partial esters derived from fatty acids and hexitol anhydrides,
for example polyethylene sorbitan monooleate. The aqueous suspensions
may also contain one or more preservatives, for example ethyl, or n-
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propyl, p-hydroxybenzoate, one or more coloring agents, one or more
flavoring agents, and one or more sweetening agents, such as sucrose,
saccharin or aspartame.
Oily suspensions may be formulated by suspending the
active ingredient in a vegetable oil, for example arachis oil, olive oil,
sesame oil or coconut oil, or in mineral oil such as liquid paraffin. The
oily suspensions may contain a thickening agent, for example beeswax,
hard paraffin or cetyl alcohol. Sweetening agents such as those set forth
above, and flavoring agents may be added to provide a palatable oral
preparation. These compositions may be preserved by the addition of
an anti-oxidant such as ascorbic acid.
Dispersible powders and granules suitable for preparation
of an aqueous suspension by the addition of water provide the active
ingredient in admixture with a dispersing or wetting agent, suspending
agent and one or more preservatives. Suitable dispersing or wetting
agents and suspending agents are exemplified by those already mentioned
above. Additional excipients, for example sweetening, flavoring and
coloring agents, may also be present.
The pharmaceutical compositions of the invention may also
be in the form of an oil-in-water emulsions. The oily phase may be a
vegetable oil, for example olive oil or arachis oil, or a mineral oil, for
example liquid paraffin or mixtures of these. Suitable emulsifying agents
may be naturally-occurring phosphatides, for example soy beans, lecithin,
and esters or partial esters derived from fatty acids and hexitol
anhydrides, for example sorbitan monooleate, and condensation products
of the said partial esters with ethylene oxide, for example polyoxyethylene
sorbitan monooleate. The emulsions may also contain sweetening and
flavouring agents.
Syrups and elixirs may be formulated with sweetening
agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such
formulations may also contain a demulcent, a preservative and flavoring
and coloring agents.
The pharmaceutical compositions may be in the form of a
sterile injectable aqueous or oleagenous suspension. This suspension may
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be formulated according to the known art using those suitable dispersing
or wetting agents and suspending agents which have been mentioned
above. The sterile injectable preparation may also be a sterile injectable
solution or suspension in a non-toxic parenterally-acceptable diluent or
solvent, for example as a solution in 1,3-butane diol. Among the
acceptable vehicles and solvents that may be employed are water, Ringer's
solution and isotonic sodium chloride solution. In addition, sterile, fixed
oils are conventionally employed as a solvent or suspending medium. For
this purpose any bland fixed oil may be employed including synthetic
mono- or diglycerides. In addition, fatty acids such as oleic acid find use
in the preparation of injectables.
Compounds of Formula I may also be administered in the
form of a suppositories for rectal administration of the drug. These
compositions can be prepared by mixing the drug with a suitable non-
irritating excipient which is solid at ordinary temperatures but liquid
at the rectal temperature and will therefore melt in the rectum to release
the drug. Such materials are cocoa butter and polyethylene glycols.
For topical use, creams, ointments, jellies, solutions or
suspensions, etc., containing the compound of Formula I are employed.
(For purposes of this application, topical application shall include mouth
washes and gargles.)
The compounds for the present invention can be
administered 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 the art. To be
administered in the form of a transdermal delivery system, the dosage
administration will, of course, be continuous rather than intermittent
throughout the dosage regimen. Compounds of the present invention
may also be delivered as a suppository employing bases such as cocoa
butter, glycerinated gelatin, hydrogenated vegetable oils, mixtures of
polyethylene glycols of various molecular weights and fatty acid esters
of polyethylene glycol.
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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
administration; the renal and hepatic function of the patient; and the
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, arrest or reverse the progress
of the condition. Optimal precision in achieving 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
elimination of a drug. Preferably, doses of the compound of structural
formula I useful in the method of the present invention range from
0.01 to 1000 mg per adult human per day. Most preferably, dosages
range from 0.1 to 500 mg/day. For oral administration, the
compositions are preferably provided in the form of tablets containing
0.01 to 1000 milligrams of the active ingredient, particularly 0.01,
0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100 and 500
milligrams of the active ingredient for the symptomatic adjustment
of the dosage to the patient to be treated. An effective amount of the
drug is ordinarily supplied at a dosage level of from about 0.0002
mg/kg to about 50 mg/kg of body weight per day. The range is more
particularly from about 0.001 mg/kg to 1 mg/kg of body weight per day.
Advantageously, the active agent of the present invention
may be administered in a single daily dose, or the total daily dosage
may be administered in dividend doses of two, three or four times
daily.
The amount of active ingredient that may be combined
with the carrier materials to produce a single dosage form will vary
depending upon the host treated and the particular mode of
administration.
It will be understood, however, that the specific dose level for
any particular patient will depend upon a variety of factors including the
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age, body weight, general health, sex, diet, time of administration, route of
administration, rate of excretion, drug combination and the severity of the
particular disease undergoing therapy.
The following examples illustrate the preparation of some of
the compounds of the invention and are not to be construed as limiting the
invention disclosed herein.
EXAMPLE 1
~S~-1-(2-Azabicyclo[2.2.2]oct-2-yD-2-~2-(3 5-dimethylphen ly )3-
[1-methyl-2-(2-pyridin-4-ylethylamino)ethy~'-1H-p r~ roloj2 3-c]p ridin
-5-yl}-2-methylpropan-1-one
_..
/j\ \
CH
3
Step lA: (,S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-f2-(3,5-dimethylphenylj-
3-[2-[N-(2,4-dinitrobenzenesulfonyl),N-(2-pyridin-4-ylethyl)-
amino]-1-methylethyl]-1H-(tent-butoxycarbonyl)pyrrolo-
[2, 3-clpyridin-5-yl~-2-methvlpropan-1-one
DEAD (59.8 ~L, 0.380 mmol) was added dropwise uaa
syringe to a stirred solution of (S~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-
dimethyl-phenyl)-3-[2-(2,4-dinitrobenzenesulfonylamino)-1-methylethyl]-
1H-(tent-butoxy-carbonyl)pyrrolo [2, 3-c] pyridin-5-yl}-2-methylprop an-1-one
(150 mg, 0.190 mmol), 4-(2-hydroxyethyl)-pyridine (46.8 mg, 0.380 mmol)
and PPhs (99. i mg, 0.380 mmol) in benzene (2 mL) at room temperature.
After approximately lh, the reaction mixture was concentrated ira uacuo
and the residue was partially purified by flash chromatography on silica
gel (80% ethyl acetate/hexanes as eluent) to give a mixture of the title
compound, 1,2-dicarbethoxyhydrazine and triphenylphosphine oxide.
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Step 1B: (S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-
3-1-methyl-2-(2-pyridin-4-ylethylamino)ethyl]-1H (tert-
butoxycarbonyl)pyrrolo [2, 3-c]pyridin-5-yl}-2-methylprop an-1-
n-Propylamine (391 ~L, 4.'75 mmol.) was added to a
stirred solution of crude (S~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-
dimethylphenyl)-3- [2- [N-(2, 4-dinitrobenzenesulfonyl),N-(2-pyridin-4-
ylethyl)amino]-1-methylethyl]-1H-(tent-butoxycarbonyl)pyrrolo [2, 3-
c]pyridin-5-yl}-2-methylpropan-1-one (0.190 mmol.) in CH2Ch (2 mL)
at room temperature. After approximately 15 min., the volatiles were
evaporated im uacuo and the residue was purified by preparative thin
layer chromatography on silica gel (double elution using 100% ethyl
acetate as eluent) to give the title compound as a foam (94.6 mg, 75%
overall yield for two steps).
Step 1C: (S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-
3-[1-methyl-2-(2-pyridin-4-ylethylamino)ethyl]-1H-pyrrolo-
[2 3-c]-pyridin-5-yl~-2-methylpropan-1-one
A solution of (S~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-
dimethylphenyl)-3-[1-methyl-2-(2-pyridin-4-ylethylamino)ethyl]-1H-
(tert-butoxycarbonyl)-pyrrolo [2, 3-c]pyridin-5-y l}-2-methylprop an-1-one
(65.0 mg, 97.9 ~,mol) in trifluoroacetic acid/CHzCl2 (1:4; 1 mL) was aged
at room temperature for approximately 9h. The resulting mixture was
concentrated i~a uacuo and the residue partitioned between saturated
aqueous NaHCOs and CHpClp. The organic phase was separated and
the aqueous phase re-extracted with CH2Cl2 (x3). The combined organic
extract was washed with brine, dried (MgS04) and concentrated i~a uacuo.
The residue was purified by flash chromatography on silica gel (gradient
elution; 2-4% methanol/1% NH40H/CH~Cla as eluent) to give the title
compound as a foam (53.4 mg, 97%).
MS (ESI) m /e = 564.6 (M+H+).
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EXAMPLE 2
~S~-1-(2-Azabicyclo(2.2.2]'oct-2-yl)-2-[3-~2~~1H-benzotriazol
5-yl)-ethylaminol-1-methylethyl}-~3 5-dimethylphenyl)
1H-pyrrolo(2 3-c]pyridin-5-yl]-2-methylpropan-1-one
H 3C CH3 CH3
N / N
O N ~ ~ N ~ \ CH3 \ ~ N N
H I H
CH3
Step 2A: (,S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-
3-2-[N-(2,4-dinitrobenzenesulfonyl),N-(2-[1-(2-trimethylsilyl-
ethoxymethyl)-1H-benzotriazol-5-yl]ethyl)amino]-1-methyl-
ethyl]-1H (tert-butoxycarbonyl)pyrrolo[2,3-c]pyridin-5-yl}-2-
methylpropan-1-one
DEAD (64.3 ~L, 0.409 mmol) was added dropwise via
syringe to a stirred solution of (,S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-
(3,5-
dimethylphenyl)-3-[2-(2,4-dinitrobenzenesulfonylamino)-1-methylethyl]-
1H-(tert-butoxy-carbonyl)pyrrolo[2,3-c]pyridin-5-yl}-2-methylpropan-
1-one (170 mg, 0.215 mmol), 2-[1-(2-trimethylsilylethoxymethyl)-1H-
benzotriazol-5-yl]ethanol (120 mg, 0.409 mmol) and PPh3 (107 mg, 0.409
mmol) in benzene (2 mL) at room temperature. After approximately 1.5h,
the reaction mixture was concentr ated i~a uacuo and the residue was
partially purified by flash chromatography on silica gel (40-60% ethyl
acetate/hexanes as eluent) to give a mixture of the title compound, 1,2-
dicarbethoxyhydrazine, triphenylphosphine oxide and the recovered
benzotriazole component.
Step 2B: (,S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-
3-2-[2-[1-(2-trimethylsilylethoxymethyl)-1H benzotriazol-5-
yl]-ethylamino]-1-methylethyl}-1H-(tent-butoxycarbonyl)
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Pyrrolo-(2, 3-clpyridin-5-~~-2-methylpropan-1-one
n-Propylamine (442 ~L, 5.38 mmol.) was added to a
stirred solution of crude (S')-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-
dimethylphenyl)-3-[2-[N (2,4-dinitrobenzenesulfonyl),N-(2-[1-(2-
trimethylsilylethoxy-methyl)-1H-benzo-triazol-5-yl]ethyl)amino]-1-
methylethyl]-1H-(tent-butoxycarbonyl)pyrrolo-[2, 3-c]pyridin-5-yl}-2-
methyl-propan-1-one (0.215 mmol.) in CHzCIz (2 mL) at room
temperature. After approximately 10 min., the volatiles were evaporated
in vacuo and the residue was partially purified by preparative thin layer
chromatography on silica gel (double elution using 100% ethyl acetate as
eluent) to give the title compound as a foam.
Step 2C: (S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-[3-{2-[2-(1H-benzotriazol-
5-yl)ethylamino]-1-methylethyl~-2-(3, 5-dimethylphenyl)-1
H-pyrrolo[2,3-c]pyridin-5-yl]-2-methylpropan-1-one
trifluoroacetic acid salt
A vigorously stirred suspension of crude (S~-1-(2-
azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-3-{2-[2-[1-(2-
trimethylsilylethoxymethyl)-1H benzo-triazol-5-yl]-ethylamino]-1-
methylethyl}-1H-(tent-butoxycarbonyl)-pyrrolo[2,3-c]pyridin-5-yl}-2-
methyl-propan-1-one (0.215 mmol.) and 2N HC1/EtOH (l:l; 1 mL)
was heated at 75°C for approximately 3h. After cooling to ambient
temperature, the reaction mixture was basified to pH=9 with 2N NaOH,
and then extracted with dichloromethane (x3). The combined organic
extract was washed with brine, dried (MgSO ~) and concentrated in uacico.
The residue was purified by reverse phase HPLC (Waters Delta Pak 15y,
C18, 100A 19x300 mm column; 25% acetonitrile/75%water - 0.1%
trifluoroacetic acid as eluent) to give the title compound as a solid (65 mg,
37% overall yield for the three steps).
MS (ESI) mle = 604.7 (M+H+).
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EXAMPLE 3
1-(2-Azabicyclof2.2.21oct-2-yl)-2-(2-(3 5-dimeth ly_phenyl)-3-~1-
methyl-2- f 2-(2-methyl-1-oxopyridin-4-yl)ethylamino] ethyl~-1H-
wrrolo[2 3-c]pyridin-5-yl)-2-methy~ropan-1-one
CH3
O
Step 3A: (S'~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-
3-[2-[N-(2,4-dinitrobenzenesulfonyl), N-(2-(2-methyl-1-oxo-
pyridin-4-yl)ethyl)amino]-1-methylethyl]-1H-(tent-butoxy-
carbonyl)pyrrolo f 2 3-c]pyridin-5-yl}-2-methylpropan-1-one
DEAD (80.0 ~L, 0.508 mmol) was added dropwise via
syringe to a stirred solution of (,5~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-f2-
(3,5-
dimethylphenyl)-3-[2-(2,4-dinitrobenzenesulfonylamino)-1-methylethyl]-
1H-(tert-butoxycarbonyl)-pyr rolo[2, 3-c]pyridin-5-yl}-2-methylpropan-1-one
(200 mg, 0.254 mmol), 4-(2-hydroxyethyl)-2-methylpyridin-1-oxide (77.8
mg, 0.508 mmol) and PPh3 (133 mg, 0.508 mmol) in benzene (5 mL) at
room temperature. After approximately 1.5h, the reaction mixture was
concentrated in vacuo and the residue was partially purified by flash
chromatography on silica gel (100% CH~Cl~ then 3%MeOH/CH2Cl~ as
eluent) to give the title compound as a foam.
Step 3B: (S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-
3-[2-(2-methyl-1-oxopyridin-4-ylethylamino)-1-methylethyl]-
1H-(tent-butoxycarbonyl)-pyrrolo [2, 3-c]pyridin-5-yl}-2-
methylpropan-1-one
~a-Propylamine (520 ~L, 6.35 mmol.) was added to a
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stirred solution of crude (S~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-
dimethylphenyl)-3-[2-[N-(2,4-dinitrobenzenesulfonyl), N-(2-(2-methyl-1-
oxopyridin-4-yl)ethyl)-.amino]-1-methylethyl]-1H-(tert-butoxycarbonyl)
pyrrolo[2,3-c]pyridin-5-yl}-2-methylpropan-1-one (0.254 mmol.) in CHaCl2
(2.5 mL) at room temperature. After approximately 2h, the volatiles
were evaporated in vacuo and the residue was purified by flash
chromatography on silica gel (100% CH2Cl2 then 3-5%MeOH/1% NH40H/
CH2C12 as eluent) to give the title compound as a foam (141 mg, 80%
overall yield for two steps).
Step 3C: 1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-(2-(3,5-dimethylphenyl)-
3-{ 1-methyl-2- [2-(2-methyl-1-oxopyridin-4-yl)ethylamino]
ethyl}-1H-pyrrolo [2, 3-c]pyridin-5-yl)-2-methylpropan-
1-one trifluoroacetic acid salt
A solution of (S~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-
dimethylphenyl)-3-[2-(2-methyl-1-oxopyridin-4-yl-ethylamino)-1-
methylethyl] -1H-(tert-butoxy-carbonyl)-pyrrolo [2, 3-c]pyr idin-5-yl}-2-
methylpropan-1-one (140 mg, 0.202 mmol) in trifluoroacetic acid/ CH2C12
(l:l; 2 mL) was aged at room temperature for approximately 2h. The
resulting mixture was concentrated ire uacuo and the residue purified by
reverse phase HPLC (Waters Delta Pak 15~, C18, 100A 19x300 mm
column; gradient elution 2'7-32% acetonitrile/water - 0.1% trifluoroacetic
acid) to give the title compound as a solid (128 mg, 77%).
MS (ESI) m /e = 594.4 (M+H+).
EXAMPLE 4
Following procedures similar to those described in Examples
1, 2 and 3 and in Schemes A to K, the following compounds are prepared:
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R8 CH3 H
R- ~A)-R~
Me
Me
X_R7~R8 _(A)_Rl
Me Me
N I
N
O
Me Me
N I ,N
O
Me Me / N~Me
N
O
O
Me Me
v
N I N
i
O
Me Me
v
~N I
/N
O
Me Me ~
,N
N~~~~
O
Me Me ~ Me
N~~
i N,a
O O
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_ _Me Me ~ N,
N ~ ~ N
O
Me Me ,Me
N ~~N
O O
PREPARATION OF SYNTHETIC INTERMEDIATES
S~-(4-Benzyloxy-3-methylbut-1-ynyl)triethylsilane
Step A: Methyl (S7-3-benzyloxv-2-methylpropanoate
An oven dried 1 L single-necked round bottom flask was
equipped with a magnetic stir bar and then charged sequentially with
15.948 g (0.135 mol) of (R)-(-)-methyl-3-hydroxy-2-methylpropanoate,
carbon tetrachloride (150 mL), cyclohexane (300 mL), and 35.796 g (0.142
mol) of benzyl 2,2,2-trichloroacetimidate. Trifluoromethanesulfonic acid
(0.8 mL; 9.0 mmol) was added to the solution and the resulting mixture
was stirred for 16 h at room temperature under an N2 atmosphere. The
reaction mixture was then filtered and the filtrate concentrated irz vacuo.
The residue was redissolved in 150 mL EtOAc and extracted with
saturated aqueous NaHCOs (1x100 mL). The organic layer was washed
with saturated NaCl, dried (MgSO ), filtered and evaporated. The
residual oil was purified on a silica gel flash chromatography column
eluted with 10% EtOAc-hexane. The purified fractions were combined
and evaporated in vacuo to afford 20.787g of the title compound as an oil.
MS (CI): m /e = 209 (M+1).
Step B: (S7-3-Benzyloxy-2-methylpropan-1-of
An oven dried three-necked 2 L round bottom flask was
equipped with a mechanical stirrer, a reflux condenser and a 500 mL
constant pressure addition funnel. The flask was charged with a solution
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of 62.252 g (0.299 mol) of methyl (,S~-3-benzyloxy-2-methylpropanoate in
600 mL of anhydrous THF, and a 1.0 M solution of lithium aluminum
hydride (300 mL; 0.3 mol) was transferred into the dropping funnel via a
cannula. Stirring was started and the lithium aluminum hydride solution
was added over 45 minutes to the reaction under an N2 atmosphere while
the temperature of the reaction mixture was maintained between 25-30°C
using an external ice-water bath. After the addition was complete, the
reaction was stirred an additional 6 h at room temperature at which point
TLC analysis (20% EtOAc-hexane) indicated complete reaction. The
reaction mixture was then cooled with an external ice-water bath and
quenched by serial addition of 11.4 mL water, 11.4 mL of 15% aqueous
NaOH, and 34.2 mL water. The reaction mixture was then filtered, the
solids were washed with EtOAc, the filtrate and washings were combined
and evaporated iv uacuo. The residue was redissolved in EtOAc, washed
with 10% aqueous NaHS04, saturated NaCI, dried (MgS04), filtered and
evaporated. The residue was purified by Kugelrohr distillation to afford
47.67 g of the title compound as an oil.
MS (CI): mle = 181 (M+1).
Step C: (,S~-3-Benzyloxy-2-methylpropanal
An oven dried three-necked 2 L round bottom flask was
equipped with a mechanical stirrer, a thermometer, an N~ inlet, and a
septum. The flask was charged with 24.050 g (0.189 mol) of oxalyl
chloride and 425 mL CHzCl~. The reaction mixture was stirred under an
N2 atmosphere and cooled to -78°C with an external dry ice-acetone
bath.
A solution of methyl sulfoxide (29.60'7 g; 0.3'19 mol) in 85 mL CHaCIz was
then added over 5 min to the reaction mixture via cannula. After the
adition, the reaction was stirred an additional 5 min and then a solution
of 31.048 g (0.172 mol) of (,S~-3-benzyloxy-2-methylpropan-1-of in 1'70 mL
CH~Clz was added via cannula. When the second addition was completed
the reaction mixture was stirred for 15 min at -78°C then 111.32 g
(0.861
mol) of N,N-diisopropylethylamine was added via syringe. The reaction
mixture was stirred an addition 15 min at -'78°C, the cooling bath was
removed and the reaction was allowed to warm. When the internal
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temperature had reached -15°C, 350 mL of a 10% aqueous NaHSO~
solution was slowly added and the mixture was transferred to a
separatory funnel. The organic layer was separated, washed with
aqueous NaHS04 (2x250 mL), saturated NaCl, dried (MgS04), filtered and
evaporated. The residue was used immediately in the next step without
further purification.
Step D: (,S~-4-Benzyloxy-1 1-dibromo-3-methylbutene
An oven dried three-necked 2 L round bottom flask was
equipped with a mechanical stirrer, a thermometer, an N2 inlet, and a
septum. The flask was charged with 180.71 g (0.689 mol) of triphenyl-
phosphine and 925 mL of CH~Cl~. The reaction mixture was stirred
under an N2 atmosphere and cooled to 0-5°C with an external ice-water
bath. The septum was then removed and 114.25 g (0.344 mol) of carbon
tetrabromide was added in portions through the open neck of the flask
at a rate that maintained the temperature of the reaction mixture below
20°C. After the addition was complete the reaction was stirred for 1 h
and
then a solution of the (S~-3-benzyloxy-2-methylpropanal from the previous
step dissolved in 150 mL of CH2Cl2 was added via cannula over a 5 min
period. The reaction mixture was stirred under N2 for an additional 1 h
and allowed to warm to room temperature. A separate 10 L three-necked
round bottom flask was equipped with a mechanical stirrer and charged
with 4 L of hexane. The stirrer was started and the crude reaction
mixture was introduced as a slow stream ~~hich resulted in formation
of a granular precipitate. After the transfer was complete the reaction
mixture was filtered and the solids were carefully washed with hexane.
The filtrate was evaporated iiz uacuo and additional solids were deposited.
The residue was resuspended in hexane, filtered and the filtrate
reevaporated. The resulting oil was purified by Kugeliohr distillation to
afford 46.54 g of the title compound as an oil.
Step E: ~,5~-(4-benzyloxy-3-methylbut-1-~nyl)triethylsilane
An oven dried 100 mL single-necked round bottom flask was
equipped with a magnetic stir bar and a septum then charged with 5.171
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g (15.5 mmol) of (,S~-4-benzyloxy-l,l-dibromo-3-methylbutene and 20 mL
of anhydrous THF. The reaction mixture was stirred at -78°C under an N
atmosphere and 12.4 mL of a 2.5 M solution of rz-butyllithium (31.0 mmol)
was added dropwise via syringe over 15 min. The reaction mixture was
stirred at -78°C for an additional 1 h, then quenched with 10% aqueous
NaHS04 and extracted into EtOAc. The organic layer was washed with
water (3x25 mL), sturated NaCl, then dried (MgSO~), filtered, and
evaporated. The residue was purified by Kugelrohr distillation to afford
3.999 g of the title compound as an oil.
(S)-1-(2-Azabicycloj2.2.2]oct-2-yl)-2-f 2-(3,5-dimethylphenyl)-3-[2-(2,4
dinitrobenzenesulfonylamino)-1-methylethyl]-1H-(tent-butoxy_
carbonYl)p r~[2,3-c]pyridin-5-yl~-2-methylpropan-1-one
02N / N02
H C O~~
H3 ~ H3 s=
n ,NH
O N~~_.~ ~ ~CH3
C
CH3
Step AA: tent-Butyl methyl 2-(5-nitropyridin-2-yl)malonate
Tert-Butylmethylmalonate (50.1 mL, 0.296 mol.) was
added dropwise, via pressure equalizing addition funnel, to a vigorously
stirred solution of 2-chloropyridine (23.4 g, 0.148 mol.) and sodium
hydride (11.8 g of a 60% dispersion in mineral oil, 0.296 mol.) in N,N-
dimethylformamide at room temperature. An exothermic reaction was
observed! After the initial exotherm had subsided, the reaction mixture
was maintained at 50°C for approximately 6h. Upon cooling to ambient,
temperature, the reaction mixture was poured into water and extracted
with ethyl acetate (x3). The combined organic extract was washed with
water, brine, dried (MgSO=~) and concentrated i~L uacuo. The residual
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yellow oil was sufficiently pure to be used without further purification in
the subsequent reaction.
Step BB: Methyl (5-nitro~yridin-2-yl)acetate
Trifluoroacetic acid (34.2 mL, 0.444 mol.) was added, uaa
syringe, to a stirred solution of crude tent-butyl methyl 2-(5-nitropyridin-
2-yl)malonate (0.148 mol.) in dichloromethane (500 mL) at ambient
temperature. After approximately 2h, the reaction mixture was poured
cautiously onto cold saturated aqueous NaHCOs and extracted with ethyl
acetate (x3). The combined organic extract was washed with brine, dried
(MgS04) and concentrated i~2 Uacuo. The residue was purified by flash
chromatography on silica gel (gradient elution; 25-40% ethyl acetate/
hexanes as eluent) to give the title compound as an orange oil (20.0 g,
69%).
Step CC: Methyl 2-methyl-2-(5-nitro~yridin-2- 1)propionate
A solution of methyl (5-nitropyridin-2-yl)acetate (20.0 g,
0.102 mol.) in N,N-dimethylformamide (50 mL) was added dropwise, Uia
pressure equalizing addition funnel, to a stirred suspension of sodium
hydride (12.2 g of a 60% dispersion in mineral oil, 0.306 mol.) in N,N-
dimethylformamide (150 mL) at -20°C. After completion of addition, the
reaction mixture was warmed to 0°C and aged for approximately lh.
After re-cooling to -20°C, methyl iodide (22.2 mL, 0.35'7 mol.) was
added.
uia pressure equalizing addition funnel, so as to maintain the internal
temperature between -15°C and -20°C. The resulting mixture was
warmed to 0°C and aged for approximately 12h. The reaction mixture
was quenched with saturated aqueous NH4Cl, poured into water and
extracted with ethyl acetate (x3). The combined organic extract was
washed with brine, dried (MgS04) and concentrated in Uacuo. The residue
was purified by flash chromatography on silica gel (gradient elution; 10-
20% ethyl acetate/hexanes as eluent) to give the title compound as a pale
yellow oil (17.5 g, 76%).
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Step DD: Methyl 2-(5-aminopyridin-2-yl)-2-meth~lpropionate
A mixture of methyl 2-methyl-2-(5-nitropyridin-2-yl)
propionate (17.5 g, 78.0 mmol.) and and Pd/C (Pd-10%; 600 mg) in
methanol (150 mL) was hydrogenated at 50 psi for 0.75h. An exothermic
reaction was observed! The resulting mixture was filtered through Celite~"'
washing copiously with methanol and the filtrate evaporated in uacuo.
The residual oil was sufficiently pure to be used without further
purification in the subsequent reaction.
Step EE: Methyl 2-[5-(2,2-dimethylpropionylamino)pyridin-
2-yl]-2-methylpropionate
Trimethylacetyl chloride (11.5 mL, 93.6 mmol.) was
added dropwise, via syringe, to a stirred solution of crude methyl 2-(5-
aminopyridin-2-yl)-2-methylpropionate (78.0 mmol.) and triethylamine
(13.0 mL, 93.6 mmol.) in a mixture of diethyl ether/THF (l:l; 600 mL) at
0°C. After approximately 0.5h, the reaction mixture was warmed to room
temperature, poured into water and extracted with ethyl acetate (x3). The
combined organic extract was washed with water, brine, dried (MgSO~)
and concentrated i~z uacuo. The residual oil was sufficiently pure to be
used without further purification in the subsequent reaction.
Step FF: 2-[5-(2,2-Dimethylpropionylamino)pyridin-
2-~1]-2-methyl-propionic acid
A vigorously stirred suspension of crude methyl 2-[5-(2,2-
dimethylpropionylamino)pyridin-2-yl]-2-methylpropionate (78.0 mmol.)
and 2.5N NaOH (65.5 mL, 0.164 mol) in methanol (150 mL) was heated
at 50°C for approximately 12h. After cooling to ambient temperature,
the volatiles were evaporated i~a vacuo, and the residue diluted with
dichloromethane. The resulting solution was acidified to pH=5 with 2N
HCl and extracted with dichloromethane (x3). The combined organic
extract was washed with brine, dried (MgS04) and concentrated i~a vacuo.
The residual solid was sufficiently pure to be used without further
purification in the subsequent reaction.
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Step GG: N-{6-[2-(2-Azabicyclo[2.2.2]oct-2-yl)-1,1-dimethyl-2-oxoethyl)-
pyridin-3-yl~-2, 2-dimethylpropionamide
PyBOP (42.6 g, 81.9 mmol) was added to a stirred mixture of
crude 2-[5-(2,2-dimethylpropionylamino)pyridin-2-yl)-2-methyl-propionic
acid (78.0 mmol), isoquinuclidine ~ HCl (12.7 g, 85.8 mmol) and
triethylamine (23.9 mL, 172 mmol) in dichloromethane (150 mL) at room
temperature. After approximately 12h, the reaction mixture was poured
into water/brine (1:1) and extracted with dichloromethane (x3). The
combined organic extract was washed with brine, dried (MgS04) and
concentrated in uacuo. The residue was purified by recrystallization from
ethyl acetate/hexanes to give the title compound as colorless needles (25.1
g, 90% overall from the product of step CC).
Step HH: N-{6-[2-(2-Azabicyclo[2.2.2]oct-2-yl)-1,1-dimethyl-2-oxoethyl]-
4-iodopyridin-3-yl~-2, 2-dimethylpropionamide
A solution of tent-butyllithium (20.6 mL of a 1.7M solution in
hexanes, 35.0 mmol) was added dropwise, via syringe, to a stirred solution
of N-{6-[2-(2-azabicyclo[2.2.2)oct-2-yl)-1,1-dimethyl-2-oxoethyl]pyridin-3-
yl}-2,2-dimethylpropionamide and N,N,N',N'-tetramethylethylenediamine
(5.28 mL, 35.0 mmol.) in THF (50 mL) at -78°C. The resulting mixture
was warmed to -45°C and aged for approximately 6h. After re-cooling to
-78°C, a solution of iodine (8.88 g, 35.0 mmol.) in THF (20 mL) was
added,
vaa syringe, so as to maintain the internal temperature <60°C. After
completion of addition, the reaction mixture was allowed to warm to
ambient temperature over approximately 6h and then quenched with
saturated aqueous NH~Cl. The resulting mixture was poured into 1M
Na2S20s and extracted with ethyl acetate (x3). The combined organic
extract was washed with brine, dried (MgS04) and concentrated in vacuo.
The residue was purified by flash chromatography on silica gel (gradient
elution; 60-80% ethyl acetate/hexanes as eluent) to give in order of
elution: the title compound as a pale yellow foam (4.67 g, 69%) followed by
recovered starting material (1.21 g, 24%).
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Step II: 2-(5-Amino-4-iodopyridin-2-yl)-1-(2-azabicyclo[2.2.2]
oct-2-yl)-2-meth~propan-1-one
A vigorously stirred mixture of N {6-[2-(2-azabicyclo
[2.2.2] oct-2-yl)-1,1-dimethyl-2-oxoethyl]-4-iodopyridin-3-yl~-2, 2-
dimethylpropionamide (4.66 g, 9.64 mmol.) in 24% H2S04 (48 mL)
was heated at 100°C for approximately 3.5h. After cooling to room
temperature, the reaction mixture was basified to pH=10 with 2.5N
NaOH and then extracted with ethyl acetate (x3). The combined
organic extract was washed with brine, dried (MgS04) and concentrated
im uacuo. The residue was purified by recrystallization from
dichloromethane/diethyl ether to give the title compound as colorless
prisms (3.02 g, 78%).
Step JJ: (,5~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-[3-(2-benzyloxy-1-
methyl-ethyl)-2-triethylsilyl-1H-pyrrolo[2,3-c]pyridin-
5-yll-2-methylpropan-1-one
A vigorously stirred suspension of 2-(5-amino-4-iodopyridin-
2-yl)-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-methylpropan-1-one (3.00 g, 7.51
mmol), (S~-(4-benzyloxy-3-methylbut-1-ynyl)triethylsilane (3.25 g, 11.3
mmol), Pd(dppf)Cl2 ~ CH2Ch (0.307 g, 0.376 mmol), LiCl (0.318 g, 7.51
mmol) and NaaC03 (1.99 g, 18.8 mmol) in N,N-dimethylformamide (60
mL) was degassed via three vacuum/nitrogen ingress cycles, and the
resulting mixture heated at 90°C for approximately 12h. After cooling
to
ambient temperature, the reaction mixture was diluted with ethyl acetate
and filtered through celite~ washing copiously with ethyl acetate. The
filtrate was poured into water/brine (1:1) and the organic phase separated.
The aqueous phase was re-extracted with ethyl acetate (x2), the combined
organic extract washed with brine, dried (MgSO~) and concentrated i~a
uacuo. The residue was purified by flash chromatography on silica gel
(gradient elution; 70-80% ethyl acetate/hexanes as eluent) to give the title
compound as a yellow foam (2.59 g, 62%).
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Step KK: (,S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-[3=(2-benzyloxy-1-
methyl-ethyl)-2-iodo-1H-pyrrolo[2, 3-c]pyridin-5-yl]-
2-methylpropan-1-one
IPy2BF4 (2.51 g, 6.75 mmol.) was added in one portion to
a stirred solution of (S)-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-[3-(2-benzyloxy-
1-methyl-ethyl)-2-triethylsilyl-1H-pyrrolo[2,3-c]pyridin-5-yl]-2-
methylpropan-1-one (2.52 g, 4.50 mmol.) in dichloromethane (45 mL) at
room temperature. Trifluoromethanesulfonic acid (1.19 mL, 13.5 mmol.)
was then added over approximately 3min, via syringe, and the resulting
mixture stirred at ambient temperature for 1.5h. The reaction mixture
was poured into cold saturated aqueous NaHC03/1M Na2S203 (1:1) and
extracted with ethyl acetate (x3). The combined organic extract was
washed with water, brine, dried (MgSO~) and concentrated irz vacuo.
The residue was purified by flash chromatography on silica gel (gradient
elution; 70-85% ethyl acetate/hexanes as eluent) to give the title
compound as a pale yellow foam (2.50 g, 97%).
Step LL: (,S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-[3-(2-benzyloxy-1-methyl-
ethyl)-2-(3, 5-dimethylphenyl)-1H-pyrrolo [2, 3-c]pyridin-5-yl]-
2-methylpropan-1-one
A vigorously stirred suspension of (,S~-1-(2-azabicyclo
[2.2.2]oct-2-yl)-2-[3-(2-benzyloxy-1-methyl-ethyl)-2-iodo-1H-pyrrolo
[2,3-c]pyridin-5-yl]-2-methylpropan-1-one (2.50 g, 4.3 i mmol), 2,5-
dimethylphenylboronic acid (1.31 g, 8.74 mmol) and Pd(dppf)Cl~ ~ CH~Clz
(0.178 g, 0.219 mmol) in toluenelMeOH (5:2; 42 mL) was degassed via
three vacuum/nitrogen ingress cycles, and the resulting mixture heated to
80°C. 1M Na2COs (10.9 mL, 10.9 mmol) was added dropwise, via syringe,
and the resulting mixture stirred vigorously at 80°C for approximately
6h.
After cooling to ambient temperature, the reaction mixture was diluted
with ethyl acetate and filtered through celite'"~ washing copiously with
ethyl acetate. The f°iltrate was poured into water and the organic
phase
separated. The aqueous phase was re-extracted with ethyl acetate (x2),
the combined organic extract washed with brine, dried (MgSOq) and
concentrated in vacuo. The residue was purified by flash chromatogr aphy
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on silica gel (gradient elution; 70-85% ethyl acetate/hexanes as eluent) to
give the title compound as a pale yellow foam (2.40 g, 100%).
Step MM: (S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{3-(2-benzyloxy-1-
methylethyl)-2-(3,5-dimethylphenyl)-1H (tert-butoxy-
carbonyl)pyrrolo~2 3-clpyridin-5-yl~-2-methylpropan l one
Di-tert-butyl-dicarbonate (1.43 g, 4.37 mmol) was added to
stirred suspension of (,S~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-[3-(2-benzyloxy-
1-methyl-ethyl)-2-(3, 5-dimethylphenyl)-1H-pyrrolo [2, 3-c]pyridin-5-yl]-2-
methylpropan-1-one (2.40 g, 4.37 mmol) and DMAP (0.053 g, 0.437 mmol)
in dichloromethane (44 mL) at room temperature. After approximately lh,
the reaction mixture was poured into water and extracted with ethyl
acetate (x3). The combined organic extract was washed with brine, dried
(MgS04) and concentrated in uacico. The residue was purified by flash
chromatography on silica gel (gradient elution; 35-45% ethyl acetate/
hexanes as eluent) to give the title compound as a colorless foam (2.54 g,
90%).
Step NN: (,S~-1-[2-(2-Azabicyclo[2.2.2]oct-2-yl)]-2-{2-(3,5-dimethyl
phenyl)-3-(2-hydroxy-1-methylethyl)-1H-(tent-butoxy-
carbonyl)pyrrolo[2 3-clpyridin-5-yl~-2-methy~ropan 1 one
A mixture of (,5~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{3-(2-
benzyloxy-1-methylethyl)-2-(3, 5-dimethylphenyl)-1H-(tent-butoxy -
carbonyl)pyrrolo[2,3-c]pyridin-5-yl}-2-methylpropan-1-one (1.94 g, 2.99
mmol) and Pd(OH)~ (Pd-20%; 100 mg) in glacial acetic acid/EtOH (1:3; 20
mL) was hydrogenated at 50 psi for 4d. The resulting mixture was filtered
through celiteU washing copiously with EtOH, the filtrate evaporated in
uacuo and the residue purified by flash chromatography on silica gel (80%
ethyl acetate/hexanes) to give the title compound as a colorless foam (1.32
g, 79%).
Step 00: (S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{3-(2-azido-1-methyl-
ethyl)-2-(3,5-dimethylphenyl) -1H-(tent-butoxycarbonyl)-
p~rrolo[2 3-clpyridin-5-yl~-2-methylpropan-1-one
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DEAD (0.38 mL, 2.42 mmol) was added dropwise, via
syringe, to a stirred solution of (S)-1-[2-(2-azabicyclo[2.2.2]oct-2-yl)]-2-
{2-(3,5-dimethylphenyl)-3-(2-hydroxy-1-methylethyl)-1H (tert-butoxy-
carbonyl)pyrrolo-[2,3-c]pyridin-5-yl}-2-methylpropan-1-one (0.338 g, 0.604
mmol), ZnNs ~ 2py (0.372 g, 1.21 mmol), PPhs (0.634 g, 2.42 mmol) and
imidazole (0.164 g, 2.42 mmol) in CH2Cl2 (6 mL) at approximately 0°C.
After allowing to warm to ambient temperature overnight, the reaction
mixture was filtered through celite~ washing copiously with
dichloromethane, and then concentrated i~z vacuo. The residue was
partially purified by flash chromatography on silica gel (gradient elution;
50-60% ethyl acetate/hexanes as eluent) to give a mixture of the title
compound contaminated with 1,2-dicarbethoxyhydrazine as a colourless
solid.
Step PP: (S~-2-{3-(2-Amino-1-methylethyl)-2-(3,5-dimethylphenyl)-
1H-(tent-butoxycarbonyl)pyrrolo [2, 3-c]pyridin-5-yl}-1-(2-
azabicyclo[2.2.2]'~oct-2-yl)-2-methylpropan-1-one
A mixture of crude (5~-1-(2-azabicyclo[2.2.2]oct-2-yl)-2-{3-(2-
azido-1-methylethyl)-2-(3,5-dimethylphenyl)-1H-(tent-butoxycarbonyl)-
pyrrolo[2,3-c]-pyridin-5-yl}-2-methylpropan-1-one (0.604 mmol) and
Pd/C (Pd-10%; 40 mg) in MeOH (6 mL) was hydrogenated at 50 psi for
approximately 1h. The resulting mixture was filtered through celiter'
washing copiously with methanol, the filtrate evaporated i~a vacuo and the
residue purified by preparative thin layer chromatography on silica gel
(double elution; 100% ethyl acetate as eluent) to give the title compound
as a colorless foam (0.265 g, '78% overall).
Step Qla: (S~-1-(2-Azabicyclo[2.2.2]oct-2-yl)-2-{2-(3,5-dimethylphenyl)-
3-2-(2, 4-dinitrobenzene sulfonylamino)-1-methylethyl] -1H-
(tent-butoxycarbonyl)pyrrolo [2, 3-c]pyridin-5-yl}-2-methyl-
propan-1-one
2,4-Dinitrobenzenesulfonyl chloride (152 mg, 0.569 mmol)
was added portionwise, to a vigorously stirred emulsion of (,S~-2-{3-(2-
amino-1-methylethyl)-2-(3, 5-dimethylphenyl)-1H-(tert-butoxycarbonyl)
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pyrrolo [2, 3-c]pyridin-5-yl}-1-(2-azabicyclo-[2.2.2]oct-2-yl)-2-methylpropan-
1-one (264 mg, 0.474 mmol) in saturated aqueous NaHCOs/ CH2Clz (1:1;
4 mL) at approximately 0°C. After 10 min., the reaction mixture was
poured into water and extracted with ethyl acetate (x3). The combined
organic extract was washed with brine, dried (MgS04) and concentrated
in uacuo. The residue was purified by flash chromatography on silica gel
(gradient elution; 40-60% ethyl acetate/hexanes as eluent) to give the title
compound as a yellow foam (299 mg, 80%).
4-(2-Hydroxyethyl)-2-methylpyridin-1-oxide
Step AAA: (2-methylpyridin-4-yl)acetic acid methyl ester (and bis-
adduct
A solution of 2,4-lutidine (10.4mL in lOmL dry
tetrahydrofuran was added dropwise over 30 minutes to a freshly
prepared solution of lithium diisopropylamide (100mmol in 60mL dry
tetrahydrofuran) at room temperature. After 4 hours, a solution of
dimethylcarbonate (7.6mL in 8mL dry tetrahydrofuran) was added and
the mixture stirred at room temperature. After 16 hours, the reaction was
quenched by the addition of saturated aqueous ammonium chloride and
extracted with ethyl acetate. The combined organics were washed with
brine and dried over sodium sulfate. Purification of the concentrate by
flash chromatography on silica gel (ethyl acetate: hexane, 2:1) gave the
title compounds (4.2g).
Step BBB: (2-meth~pyridin-4-yl)-acetic acid hydrochloride
A solution of 2-methylpyridin-4-yl)acetic acid methyl ester
and (bis)adduct (2.Og in lOmL concentrated hydrochloric acid) was heated
to reflux on an oil bath. After 1 hour the mixture was cooled to room
temperature, diluted with toluene and concentrated in uacuo to provide
the crude title compound (1.67g).
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Step CCC: (2-methylpyridin-4-yl)acetic acid ethyl ester
To a solution of (2-methylpyridin-4-yl)acetic acid (10g in
50mL ethanol) was added 0.50mL concentrated sulfuric acid and the
mixture heated to reflux on an oil bath. After 3 hours, the mixture was
cooled to room temperature and concentrated in vacuo. The residue was
solvated in water and neutralized by the addition of 2N ammonium
hydroxide. The mixture was then extracted with ethyl acetate, washed
with brine and dried over sodium sulfate. Concentration irz vacuo
provided the crude title compound as a light brown oil (8.94g).
Step DDD: 2-(2-methylpyridin-4-~l)-ethanol
To a solution of (2-methylpyridin-4-yl)-acetic acid ethyl ester
(8.9g in 50mL dry tetrahydrofur an) at 0°C was added lithium aluminum
hydride (50mL of a 1M solution in tetrahydrofuran) and the mixture
stirred at low temperature. After 30 minutes, the reaction was quenched
by the sequential addition of 1.85mL water, 1.39mL 5N sodium hydroxide
and 5.55mL water. After 10 minutes, the mixture was filtered through
diatomaceous earth and the filtrate extracted with ether. The combined
organics were concentrated in uacuo to give the crude title compound as a
brown oil (S.Og).
Step EEE: 4-(2-hydroxyethyl)-2-methylpvridin-1-oxide
To a solution of 2-(2-methylpyridin-4-yl)-ethanol (1.5g in 6mL
acetic acid) was added 4.2mL of a 30% solution of hydrogen peroxide and
the mixture heated to 80°C on an oil bath. After '7 hours, the mixture
was
cooled to room temperature and concentrated i~L uacuo. The residue was
resolvated in methylene chloride and the excess acetic acid quenched by
the careful addition of solid sodium carbonate. The mixture was then
filtered and the residue washed with ethyl acetate then methylene
chloride:methanol (3:1). Purification of the concentrated filtrate by flash
chromatography on silica gel (methylene chloride:methanol, 95:5, then
90:10) gave the title compound as a colorless oil (1.2g). MS ESI + f~,llMS
m/z 154.2
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WO 00/53181 PCT/US00/05933
1H NMR (500 MHz, CD30D) 8 2.46 (s, 3H), 2.'79 (t, J = 6.18 Hz, 5.95 Hz,
2H), 3.87 (t, ~I = 5.95Hz, 6.18Hz, 2H), 7.00 (m, 1H), 7.13 (s, 1H), 8.08 (d,
~T
= 6.64Hz, 1H).
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