U.S. patent application number 11/274030 was filed with the patent office on 2006-08-03 for 8-quinolinxanthine and 8-isoquinolinxanthine derivatives as pde 5 inhibitors.
Invention is credited to Gurdip Bhalay, Stephen Paul Collingwood, Robin Alec Fairhurst, Sylvie Felicite Gomez, Reto Naef, David Andrew Sandham.
Application Number | 20060173181 11/274030 |
Document ID | / |
Family ID | 34229051 |
Filed Date | 2006-08-03 |
United States Patent
Application |
20060173181 |
Kind Code |
A1 |
Bhalay; Gurdip ; et
al. |
August 3, 2006 |
8-Quinolinxanthine and 8-isoquinolinxanthine derivatives as PDE 5
inhibitors
Abstract
A compound of formula (I) ##STR1## R.sup.1 is hydrogen or alkyl
optionally substituted by hydroxy, alkoxy, or alkylthio, R.sup.2 is
hydrogen, alkyl, hydroxyalkyl, alkylcarbonyloxyalkyl, alkoxyalkyl,
alkylthioalkyl, alkenyl, cycloalkylalkyl, heterocyclylalkyl,
aralkyl in which the aryl ring thereof is optionally fused to a
5-membered heterocyclic group or is optionally substituted by one
or more substituents selected from alkoxy, amino, alkylamino,
dialkylamino, acylamino, halogen, hydroxy, aminosulfonyl,
alkylaminosulfonyl, dialkylaminosulfonyl, alkylsulfonylamino or
dialkylaminosulfonylamino, R.sup.3 is hydrogen or alkyl optionally
substituted by hydroxy, alkoxy, or alkylthio, R.sup.4 is hydrogen
or alkyl, R.sup.5 is a quinolinyl, isoquinolinyl or
oxodihydroisoquinolinyl group optionally fused to a 5-membered
heterocyclic group and optionally substituted by one or more
substituents selected from halogen, cyano, hydroxy, alkyl,
hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkoxy, alkylthio,
alkenyl, alkoxycarbonyl, alkynyl, carboxyl, acyl, a group of
formula --N(R.sup.6)R.sup.7, aryl optionally substituted by one or
more substituents selected from halogen or alkoxy, or heteroaryl
having 5 or 6 ring atoms attached through a ring carbon atom to the
indicated carbon atom, and R.sup.6 and R.sup.7 are each
independently hydrogen or alkyl optionally substituted by hydroxy
or alkoxy or one of R.sup.6 and R.sup.7 is hydrogen and the other
is acyl, or R.sup.6 and R.sup.7 together with the nitrogen atom to
which they are attached denote a 5- or 6-membered heterocyclyl
group.
Inventors: |
Bhalay; Gurdip; (Horsham,
GB) ; Collingwood; Stephen Paul; (Crawley, GB)
; Fairhurst; Robin Alec; (Ashington, GB) ; Gomez;
Sylvie Felicite; (Redcliff, GB) ; Naef; Reto;
(Rheinfelden, CH) ; Sandham; David Andrew;
(Horsham, GB) |
Correspondence
Address: |
NOVARTIS;CORPORATE INTELLECTUAL PROPERTY
ONE HEALTH PLAZA 104/3
EAST HANOVER
NJ
07936-1080
US
|
Family ID: |
34229051 |
Appl. No.: |
11/274030 |
Filed: |
November 15, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10937639 |
Sep 9, 2004 |
7019136 |
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11274030 |
Nov 15, 2005 |
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10644328 |
Aug 20, 2003 |
6919337 |
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10937639 |
Sep 9, 2004 |
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10240481 |
Oct 2, 2002 |
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PCT/EP01/03909 |
Apr 5, 2001 |
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10644328 |
Aug 20, 2003 |
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Current U.S.
Class: |
544/268 |
Current CPC
Class: |
C07D 239/545 20130101;
C07D 473/06 20130101; C07D 473/04 20130101; A61K 31/522
20130101 |
Class at
Publication: |
544/268 ;
514/263.22 |
International
Class: |
C07D 473/04 20060101
C07D473/04; A61K 31/522 20060101 A61K031/522 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 7, 2000 |
GB |
0008694.2 |
Claims
1-12. (canceled)
13. A method of treating stable, unstable and variant (Prinzmetal)
angina, hypertension, pulmonary hypertension, congestive heart
failure, atherosclerosis, conditions of reduced blood vessel
patency, or peripheral vascular disease comprising administering a
therapeutically effective amount of a pharmaceutical composition
comprising a compound of formula ##STR65## in free or salt form,
wherein R.sup.1 is hydrogen or alkyl optionally substituted by
hydroxy, alkoxy, or alkylthio, R.sup.2 is hydrogen, alkyl,
hydroxyalkyl, alkylcarbonyloxyalkyl, alkoxyalkyl, alkylthioalkyl,
alkenyl, cycloalkylalkyl, heterocyclylalkyl, aralkyl in which the
aryl ring thereof is optionally fused to a 5-membered heterocyclic
group or is optionally substituted by one or more substituents
selected from alkoxy, amino, alkylamino, dialkylamino, acylamino,
halogen, hydroxy, aminosulfonyl, alkylaminosulfonyl,
dialkylaminosulfonyl, alkylsulfonylamino or
dialkylaminosulfonylamino, R.sup.3 is hydrogen or alkyl optionally
substituted by hydroxy, alkoxy, or alkylthio, R.sup.4 is hydrogen
or alkyl, R.sup.5 is a quinolinyl, isoquinolinyl or
oxodihydroisoquinolinyl group optionally fused to a 5-membered
heterocyclic group and optionally substituted by one or more
substituents selected from halogen, cyano, hydroxy, alkyl,
hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkoxy, alkylthio,
alkenyl, alkoxycarbonyl, alkynyl, carboxyl, acyl, a group of
formula --N(R.sup.5)R.sup.7, aryl optionally substituted by one or
more substituents selected from halogen or alkoxy, or heteroaryl
having 5 or 6 ring atoms attached through a ring carbon atom to the
indicated carbon atom, and R.sup.6 and R.sup.7 are each
independently hydrogen or alkyl optionally substituted by hydroxy
or alkoxy or one of R.sup.6 and R.sup.7 is hydrogen and the other
is acyl, or R.sup.6 and R.sup.7 together with the nitrogen atom to
which they are attached denote a 5- or 6-membered heterocyclyl
group.
14. The method of claim 13 wherein the PDE 5 inhibitor is
3-isobutyl-8-(6-methoxy-isoquinolin-4-ylmethyl)-1-methyl-3,7-dihydro-puri-
ne-2,6-dione.
15. The method of claim 13 wherein a condition of reduced blood
vessel patency is post-percutaneous transluminal coronary
angioplasty.
Description
[0001] butyl, straight or branched pentyl, straight or branched
hexyl, straight or branched heptyl, straight or branched octyl,
straight or branched nonyl or straight or branched decyl.
Preferably alkyl is C.sub.1-C.sub.8-alkyl.
[0002] "Alkoxy" as used herein denotes straight chain or branched
alkoxy which may be, for example, C.sub.1-C.sub.10-alkoxy such as
methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy,
sec-butoxy, tert-butoxy, straight or branched pentoxy, straight or
branched hexyloxy, straight or branched heptyloxy, straight or
branched octyloxy, straight or branched nonyloxy or straight or
branched decyloxy. Preferably, alkoxy is
C.sub.1-C.sub.4-alkoxy.
[0003] "Alkylthio" as used herein may be C.sub.1 to
C.sub.10-alkylthio such as methylthio, ethylthio, n-propylthio,
isopropylthio, n-butylthio, sec-butylthio, isobutylthio,
tert-butylthio, pentylthio, hexylthio, heptylthio, octylthio,
nonylthio or decylthio. Preferably alkylthio is C.sub.1 to
C.sub.4-alkylthio.
[0004] "Alkenyl" as used herein means straight chain or branched
alkenyl, which may be, for example, C.sub.2 to C.sub.10-alkenyl
such as vinyl, 1-propenyl, 2-propenyl, 1-butenyl, isobutenyl, or
straight or branched pentenyl, hexenyl, heptenyl, octenyl, nonenyl
or decenyl. Preferred alkenyl is C.sub.2 to C.sub.4-alkenyl.
[0005] "Cycloalkylalkyl" as used herein denotes alkyl, for example
C.sub.1 to C.sub.10-alkyl such as one of the C.sub.1 to
C.sub.10-alkyl groups hereinbefore mentioned, substituted by a
C.sub.3 to C.sub.8 cycloalkyl group such as cyclopropyl,
methylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
methylcyclohexyl, dimethylcyclohexyl, cycloheptyl or cyclooctyl.
Preferably, cycloalkylalkyl is
C.sub.3-C.sub.6-cycloalkyl-C.sub.1-C.sub.4-alkyl.
[0006] "Heterocyclylalkyl" as used herein denotes alkyl, for
example C.sub.1 to C.sub.10-alkyl such as one of the C.sub.1 to
C.sub.10-alkyl groups hereinbefore mentioned, substituted by a 5-
or 6-membered heterocyclyl group having one or two hetero atoms
selected from nitrogen, oxygen and sulfur in the ring, such as
pyrrolyl, pyrrolidinyl, furyl, thienyl, pyridyl, piperidyl,
imidazolyl, imidazolidinyl, pyrazolidinyl, piperazinyl,
morpholinyl, oxazolyl, or furazanyl. Preferably, heterocyclylalkyl
is C.sub.1-C.sub.4-alkyl substituted by a 5- or 6-membered
heterocyclyl group having one or two nitrogen or oxygen atoms or
one nitrogen atom and one oxygen atom in the ring.
[0007] "Aralkyl" as used herein means
C.sub.6-C.sub.10-aryl-C.sub.1-C.sub.10 alkyl and may be, for
example, one of the C.sub.1-C.sub.10-alkyl groups mentioned
hereinbefore, particularly one of the C.sub.1-C.sub.4-alkyl groups,
substituted by phenyl, tolyl, xylyl or naphthyl. Preferably,
aralkyl is phenyl-C.sub.1-C.sub.4-alkyl, particularly benzyl or
2-phenylethyl.
[0008] "Acyl" as used herein denotes alkylcarbonyl, for example
C.sub.1-C.sub.10-alkylcarbonyl where C.sub.1-C.sub.10-alkyl may be
one of the C.sub.1-C.sub.10-alkyl groups hereinbefore mentioned,
optionally substituted by one or more halogen atoms;
cycloalkylcarbonyl, for example C.sub.3-C.sub.8-cycloalkylcarbonyl
where C.sub.3-C.sub.8-cycloalkyl may be, for example, cyclopropyl,
cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl; 5-
or 6-membered heterocyclylcarbonyl having one or two hetero atoms
selected from nitrogen, oxygen and sulfur in the ring, such as
furylcarbonyl or pyridylcarbonyl; arylcarbonyl, for example
C.sub.6-C.sub.10-arylcarbonyl such as benzoyl; or aralkylcarbonyl,
for example C.sub.6 to C.sub.10-aryl-C.sub.1-C.sub.4-alkylcarbonyl
such as benzylcarbonyl or phenylethylcarbonyl. Preferably acyl is
C.sub.1-C.sub.4-alkylcarbonyl.
[0009] "Alkynyl" as used herein denotes straight or branched
alkynyl, for example C.sub.2 to C.sub.6-alkynyl such as ethynyl,
propargyl, 2-butynyl, pentynyl or hexynyl. Preferably alkynyl is
C.sub.2-C.sub.4-alkynyl.
[0010] "Aryl" as used herein denotes a monovalent carbocylic
aromatic group, for example C.sub.6-C.sub.10-aryl such as phenyl,
phenyl substituted by one or more, e.g. one, two or three,
C.sub.1-C.sub.4-alkyl groups, or naphthyl. Preferably aryl is
phenyl.
[0011] "Heteroaryl having 5 or 6 ring atoms" as used herein denotes
a monovalent aromatic heterocyclic group having 5 or 6 ring atoms
of which one, two or three are selected from nitrogen, oxygen and
sulfur, such as pyrrolyl, furyl, thienyl, pyridyl, pyrazolyl,
imidazolyl, triazolyl, oxazolyl, isoxazolyl, thiazolyl,
isothiazolyl, dithiazolyl, trithiazolyl, furazanyl, pyrazinyl,
pyrimidinyl or triazinyl.
[0012] In alkylamino, dialkylamino, acylamino,
dialkylaminosulfonylamino, alkylcarbonyl, alkylcarbonyloxy,
alkoxycarbonyl, hydroxyalkyl, alkylthioalkyl and alkoxyalkyl, the
alkyl, acyl or alkoxy groups as appropriate have the meanings
hereinbefore described.
[0013] "Halogen" as used herein may be fluorine, chlorine, bromine
or iodine; preferably it is fluorine, chlorine or bromine.
[0014] The 5-membered heterocyclic ring to which R.sup.5 as a
quinolinyl, isoquinolinyl or oxodihydroisoquinolinyl group is
optionally fused may be, for example, a 5-membered heterocyclic
ring having one or two hetero atoms in the ring, said hetero atoms
being selected from oxygen, nitrogen and sulfur. Examples of such
heterocyclic rings include pyrrole, pyrroline, pyrrolidine, furan,
dihydrofuran, tetrahydrofuran, thiophene, dihydrothiophene,
tetrahydrothiophene, imidazole, imidazoline, imidazolidine,
pyrazole, pyrazoline, pyrazolidine, dioxolane, oxazole, isoxazole,
thiazole and isothiazole rings. Preferably the 5-membered
heterocyclic ring is a saturated ring having two hetero atoms,
preferably two oxygen or two nitrogen atoms, especially two oxygen
atoms.
[0015] R.sup.5 as a quinolinyl group may be a 2-quinolinyl,
3-quinolinyl, 4-quinolinyl, 5-quinolinyl, 6-quinolinyl,
7-quinolinyl or 8-quinolinyl group, preferably a 4-quinolinyl,
5-quinolinyl or 8-quinolinyl group. R.sup.5 as an isoquinolinyl
group may be a 1-isoquinolinyl, 3-isoquinolinyl, 4-isoquinolinyl,
5-isoquinolinyl, 6-isoquinolinyl, 7-isoquinolinyl, or
8-isoquinolinyl group, preferably a 1-isoquinolinyl or
4-isoquinolinyl group. In most of the especially preferred
embodiments of the invention, R.sup.5 is a 4-isoquinolinyl
group.
[0016] R.sup.5 as a substituted quinolinyl or isoquinolinyl group
is preferably substituted by one, two, three or four of the
abovementioned substituents, especially one, two or three of those
substituents. The preferred substituted 4-isoquinolinyl group is
preferably substituted in the 1- and/or 6- and/or 7- and/or
8-position of the isoquinoline ring system.
[0017] In especially preferred embodiments of the invention,
R.sup.5 is a quinolinyl group of formula ##STR2## or an
isoquinolinyl group of formula ##STR3## where R.sup.8, R.sup.9,
R.sup.10, R.sup.11, R.sup.12 and R.sup.13 are each independently
hydrogen or a substituent selected from halogen, cyano, hydroxy,
alkyl, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkoxy,
alkylthio, alkenyl, alkoxycarbonyl, alkynyl, carboxyl, acyl, a
group of formula --N(R.sup.6)R.sup.7, aryl optionally substituted
by one or more substituents selected from halogen or alkoxy, or
heteroaryl having 5 or 6 ring atoms, or R.sup.11 and R.sup.12
together with the carbon atoms to which they are attached denote a
5-membered heterocyclic group having two oxygen or nitrogen atoms
in the ring, and R.sup.6 and R.sup.7 are as hereinbefore
defined.
[0018] R.sup.5 as an oxodihydroisoquinolinyl group preferably has
the oxo group ortho to the ring nitrogen atom, preferably in the
1-position in the isoquinoline ring system. It is preferably linked
to the remainder of the molecule of formula I via the ring carbon
atom meta to the ring nitrogen atom, i.e. the 4-position in the
isoquinoline ring system. An especially preferred
oxodihydroisoquinolinyl group is of formula ##STR4## where
R.sup.10, R.sup.11, R.sup.12 and R.sup.13 are as hereinbefore
defined and R.sup.a is hydrogen or C.sub.1-C.sub.4-alkyl.
[0019] Preferred among the compounds of formula I in free or salt
form are those where R.sup.1 is hydrogen or C.sub.1-C.sub.4-alkyl
optionally substituted by hydroxy, C.sub.1-C.sub.4-alkoxy or
C.sub.1-C.sub.4-alkylthio,
[0020] R.sup.2 is hydrogen, C.sub.1-C.sub.8-alkyl,
hydroxy-C.sub.1-C.sub.8-alkyl,
C.sub.1-C.sub.4-alkylcarbonyloxy-C.sub.1-C.sub.8-alkyl,
C.sub.1-C.sub.4-alkoxy-C.sub.1-C.sub.8-alkyl,
C.sub.1-C.sub.4-alkylthio-C.sub.1-C.sub.8-alkyl,
C.sub.2-C.sub.4-alkenyl,
C.sub.3-C.sub.8-cycloalkyl-C.sub.1-C.sub.4-alkyl,
heterocyclyl-C.sub.1-C.sub.4-alkyl where the heterocyclyl group is
a 5- or 6-membered heterocyclyl group having one or two hetero
atoms selected from nitrogen and oxygen atoms in the ring,
phenyl-C.sub.1-C.sub.4-alkyl in which the phenyl ring is optionally
substituted by one or more substituents selected from
C.sub.1-C.sub.4-alkoxy, amino, C.sub.1-C.sub.4-alkylamino,
di(C.sub.1-C.sub.4-alkyl)amino, C.sub.1-C.sub.4-alkylcarbonylamino,
halogen, C.sub.1-C.sub.4-alkylsulfonylamino, or
di(C.sub.1-C.sub.4-alkyl)aminosulfonylamino, and is optionally
fused to a 5-membered heterocyclic ring having two oxygen or two
nitrogen atoms in the ring,
[0021] R.sup.3 is hydrogen or C.sub.1-C.sub.4-alkyl optionally
substituted by hydroxy, C.sub.1-C.sub.4-alkoxy or
C.sub.1-C.sub.4-alkylthio,
[0022] R.sup.4 is hydrogen or C.sub.1-C.sub.4-alkyl,
[0023] R.sup.5 is a quinolinyl, isoquinolinyl or
oxodihydroisoquinolinyl group optionally fused to a 5-membered
heterocyclic group having two oxygen or two nitrogen atoms in the
ring and optionally substituted by one or more substituents
selected from halogen, cyano, carboxy hydroxy,
C.sub.1-C.sub.4-alkyl, hydroxy-C.sub.1-C.sub.4-alkyl,
C.sub.1-C.sub.4-alkoxy-C.sub.1-C.sub.4-alkyl,
C.sub.1-C.sub.4-alkylthio-C.sub.1-C.sub.4-alkyl,
C.sub.1-C.sub.4-alkoxy, C.sub.1-C.sub.4-alkylthio,
C.sub.2-C.sub.4-alkenyl, C.sub.2-C.sub.4-alkynyl,
C.sub.1-C.sub.4-alkylcarbonyl, a group --N(R.sup.6)R.sup.7 or
phenyl optionally substituted by one or more substituents selected
from halogen or C.sub.1-C.sub.4-alkoxy and
[0024] R.sup.6 and R.sup.7 are each independently hydrogen or
C.sub.1-C.sub.4-alkyl optionally substituted by hydroxy or alkoxy,
or one of R.sup.6 and R.sup.7 is hydrogen and the other is
C.sub.1-C.sub.4-alkylcarbonyl, or R.sup.6 and R.sup.7 together with
the nitrogen atom to which they are attached denote a 5- or
6-membered heterocyclyl group having one or two nitrogen atoms and,
optionally, an oxygen atom in the ring.
[0025] Further preferred among the compounds of formula I are those
where
[0026] R.sup.1 is hydrogen or C.sub.1-C.sub.4-alkyl, R.sup.2 is
hydrogen, C.sub.1-C.sub.8-alkyl, hydroxy-C.sub.1-C.sub.8-alkyl, or
C.sub.1-C.sub.4-alkylcarbonyloxy-C.sub.1-C.sub.1-alkyl,
C.sub.2-C.sub.4-alkenyl,
C.sub.3-C.sub.6-cycloalkyl-C.sub.1-C.sub.4-alkyl,
heterocyclyl-C.sub.1-C.sub.4-alkyl where the heterocyclyl group is
a 5-membered heterocyclyl group having one nitrogen or oxygen atom
in the ring, phenyl-C.sub.1-C.sub.4-alkyl in which the phenyl ring
is optionally substituted by one or two substituents selected from
C.sub.1-C.sub.4-alkoxy, amino, C.sub.1-C.sub.4-alkylcarbonylamino,
chlorine, bromine, C.sub.1-C.sub.4-alkylsulfonylamino, or
di(C.sub.1-C.sub.4-alkyl)aminosulfonylamino and is optionally fused
to a 5-membered heterocyclic ring having two oxygen atoms in the
ring,
[0027] R.sup.3 is hydrogen or C.sub.1-C.sub.4-alkyl,
[0028] R.sup.4 is hydrogen or C.sub.1-C.sub.4-alkyl,
[0029] R.sup.5 is a quinolinyl group of formula II, an
isoquinolinyl group of formula III or an oxodihydroisoquinolinyl
group of formula IIIA, where R.sup.8, R.sup.9, R.sup.10, R.sup.11,
R.sup.12 and R.sup.13 are each independently selected from
hydrogen, halogen, cyano, carboxy, hydroxy, C.sub.1-C.sub.4-alkyl,
hydroxy-C.sub.1-C.sub.4-alkyl,
C.sub.1-C.sub.4-alkoxy-C.sub.1-C.sub.4-alkyl,
C.sub.1-C.sub.4-alkylthioC.sub.1-C.sub.4-alkyl,
C.sub.1-C.sub.4-alkoxy, C.sub.1-C.sub.4-alkylthio,
C.sub.2-C.sub.4-alkenyl, C.sub.2-C.sub.4-alkynyl,
C.sub.1-C.sub.4-alkylcarbonyl, a group --N(R.sup.6)R.sup.7 or
phenyl optionally substituted by one or two substituents selected
from halogen or C.sub.1-C.sub.4-alkoxy, or R.sup.11 and R.sup.12
together with the carbon atoms to which they are attached denote a
5-membered heterocyclic group having two oxygen atoms in the ring,
and
[0030] R.sup.6 and R.sup.7 are each independently hydrogen or
C.sub.1-C.sub.4-alkyl optionally substituted by hydroxy or alkoxy
or one of R.sup.6 and R.sup.7 is hydrogen and the other is
C.sub.1-C.sub.4-alkylcarbonyl, or R.sup.6 and R.sup.7 together with
the nitrogen atom to which they are attached denote a 6-membered
heterocyclyl group having one or two nitrogen atoms, or one
nitrogen atom and one oxygen atom, in the ring.
[0031] Amongst the further preferred compounds hereinbefore
described, especially preferred compounds are usually those in
which R.sup.5 is an isoquinolinyl group of formula III in which
R.sup.8 is hydrogen, C.sub.1-C.sub.4-alkyl, halogen, cyano,
--N(R.sup.6)R.sup.7 where R.sup.6 and R.sup.7 are independently
C.sub.1-C.sub.4-alkyl or R.sup.6 and R.sup.7 together with the
nitrogen atom to which they are attached denote a 6-membered
heterocyclyl group having one or two nitrogen atoms, or one
nitrogen atom and one oxygen atom, in the ring, or phenyl
substituted by one or two C.sub.1-C.sub.4-alkoxy groups;
[0032] R.sup.9 and R.sup.10 are each independently hydrogen,
C.sub.1-C.sub.4-alkyl or halogen; R.sup.11 and R.sup.12 are each
independently hydrogen, halogen, cyano, carboxy, hydroxy,
C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-alkoxy or
C.sub.2-C.sub.4-alkynyl, or R.sup.11 and R.sup.12 together with the
carbon atoms to which they are attached denote a 5-membered
heterocycle having two oxygen atoms in the ring; and R.sup.13 is
hydrogen or halogen.
[0033] Specific especially preferred compounds of formula I are
those hereinafter described in the Examples. More preferred amongst
these compounds are those of Examples 7, 10, 15, 35, 45, 49, 55,
60, 68 and 70.
[0034] Compounds of formula I may be in the form of salts,
particularly pharmaceutically acceptable salts. Pharmaceutically
acceptable acid addition salts of compounds of formula I include
those of inorganic acids, for example, hydrohalic acids such as
hydrofluoric acid, hydrochloric acid, hydrobromic acid or
hydroiodic acid, nitric acid, sulfuric acid, phosphoric acid; and
organic acids, for example aliphatic monocarboxylic acids such as
formic acid, acetic acid, trifluoroacetic acid, propionic acid and
butyric acid, aliphatic hydroxy acids such as lactic acid, citric
acid, tartaric acid or malic acid, dicarboxylic acids such as
maleic acid or succinic acid, aromatic carboxylic acids such as
benzoic acid, p-chlorobenzoic acid, diphenylacetic acid or
triphenylacetic acid, aromatic hydroxy acids such as
o-hydroxybenzoic acid, p-hydroxybenzoic acid,
1-hydroxynaphthalene-2-carboxylic acid or
3-hydroxynaphthalene-2-carboxylic acid, and sulfonic acids such as
methanesulfonic acid or benzenesulfonic acid. Pharmaceutically
acceptable base salts of compounds of formula I where R.sup.3 is
hydrogen include metal salts, particularly alkali metal or alkaline
earth metal salts such as sodium, potassium, magnesium or calcium
salts, and salts with ammonia or pharmaceutically acceptable
organic amines or heterocylic bases such as ethanolamines,
benzylamines or pyridine. These salts may be prepared from free
compounds of formula I or other salts of compounds of formula I by
known salt-forming procedures.
[0035] The present invention also provides a process for the
preparation of compounds of formula I in free or salt form which
comprises
[0036] 1) (a) dehydrating a compound of formula ##STR5## where
R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are as hereinbefore defined;
or
[0037] (b) for the preparation of a compound of formula I in free
or salt form where R.sup.3 is alkyl optionally substituted by
hydroxy, alkoxy or alkylthio, reacting a compound of formula I in
free or salt form with an appropriate alkylating agent, or
[0038] (c) for the preparation of a compound of formula I in free
or salt form where R.sup.2 is aralkyl substituted in the aryl ring
by alkylsulfonylamino or dialkylaminosulfonylamino, reacting a
compound of formula I in salt form where R.sup.2 is aralkyl
substituted by amino with, respectively, an alkylsulfonyl halide or
dialkylaminosulfonyl halide; or
[0039] (d) for the preparation of a compound of formula I in free
or salt form where R.sup.2 is hydroxy-substituted alkyl, hydration
of a compound of formula I where R.sup.2 is alkenyl; or
[0040] (e) for the preparation of a compound of formula I in free
or salt form where R.sup.2 is alkyl substituted by
alkylcarbonyloxy, appropriate esterification of a compound of
formula I where R.sup.2 is hydroxy-substituted alkyl; or
[0041] (f) for the preparation of a compound of formula I in free
or salt form where R.sup.2 is aralkyl substituted in the aryl ring
by amino, hydrolysing a compound of formula I where R.sup.2 is
aralkyl substituted in the aryl ring by acylamino; or
[0042] (g) for the preparation of a compound of formula I in free
or salt form where R.sup.5 is quinolinyl or isoquinolinyl
substituted by hydroxy, dealkylation of a compound of formula I
where R.sup.5 is respectively quinolinyl or isoquinolinyl
substituted by alkoxy, particularly methoxy; or
[0043] (h) for the preparation of a compound of formula I in free
or salt form where R.sup.5 is quinolinyl or isoquinolinyl
substituted by halogen, halogenation of a compound of formula I
where R.sup.5 is respectively quinolinyl or isoquinolinyl having an
unsubstituted ring carbon atom available for halogenation; or
[0044] (i) for the preparation of a compound of formula I in free
or salt form where R.sup.2 is a cyclopropyl group, optionally
substituted by alkyl, subjecting a compound of formula I where
R.sup.2 is alkenyl to a Simmons Smith cyclopropanation reaction;
and
[0045] 2) recovering the resulting product of formula I in free or
salt form.
[0046] Process (a) may be carried out by heating, or by reaction
with an inorganic or organic base. It may be effected in an organic
or aqueous solvent or mixed aqueous/organic solvent. The reaction
with base may be carried out at ambient temperature or, more
conveniently, at elevated temperature. The reaction is preferably
carried out by treatment with aqueous alkali metal hydroxide in an
alcoholic solvent at elevated temperature, for example as described
hereinafter in the Examples. The compound of formula IV is
preferably a compound where R.sup.5 is a group of formula II or
III. Compounds of formula IV may be prepared by reacting a compound
of formula ##STR6## where R.sup.1 and R.sup.2 are as hereinbefore
defined, with a compound of formula ##STR7## or an amide-forming
derivative thereof, where R.sup.4 and R.sup.5 are as hereinbefore
defined. The reaction may be effected by treating the carboxylic
acid of formula VI with a peptide coupling agent to form in situ an
activated ester or mixed anhydride, followed by treatment with the
compound of formula V in an organic, e.g. dipolar aprotic, or mixed
aqueous-organic (e.g. chlorohydrocarbon) solvent. The latter
treatment may be carried out at sub-ambient, ambient or elevated
temperature, conveniently at ambient temperature. Preferably, the
acid of formula VI is treated with a carbodiimide derivative in the
presence of hydroxybenzotriazole and, optionally, a base, or is
treated with a benzotriazolyl-(trisdialkylamino)-oxyphosphonium
salt. The resulting intermediate is preferably treated with the
compound of formula V in a dipolar aprotic solvent or mixed
chlorohydrocarbon-aqueous solvent at ambient temperature.
Procedures may be as hereinafter described in the Examples.
[0047] Compounds of formula V may be prepared by reduction of a
compound of formula ##STR8## where R.sup.1 and R.sup.2 are as
hereinbefore defined.
[0048] The reduction may be effected using known procedures, for
example by treating the compound of formula VII with a reducing
agent in an organic or aqueous solvent. The reaction may be carried
out at ambient or, more conveniently, at elevated temperature.
Preferred reducing agents are alkali metal dithionite salts in
aqueous media or hydrogen in the presence of a noble metal
catalyst. Treatment with sodium dithionite in aqueous solution at
80-90.degree. C. is particularly preferred.
[0049] Compounds of formula VII may be prepared by nitrosation of a
compound of formula ##STR9## where R.sup.1 and R.sup.2 are as
hereinbefore defined, for example with an organic or inorganic
nitrosating agent in an organic or aqueous or mixed organic-aqueous
solvent. Nitrosation may be effected using known procedures at
sub-ambient, ambient or elevated temperature, preferably with an
alkali metal nitrite such as sodium nitrite in the presence of an
acid such acetic acid at sub-ambient or ambient temperature,
preferably in a mixed alcoholic-aqueous solvent such as aqueous
ethanol.
[0050] Compounds of formula VIII may be prepared by reacting a
compound of formula ##STR10## where R.sup.2 is as hereinbefore
defined with an inorganic or organic base to effect cyclisation,
followed, where R.sup.1 is an optionally substituted alkyl group,
by reaction with an alkylating agent. The cyclisation reaction may
be effected using conventional procedures. It is conveniently
carried out in an aqueous, organic or mixed organic-aqueous
solvent. Reaction may be effected at ambient or, more conveniently,
elevated temperature. The base is preferably an alkali metal
hydroxide, especially sodium hydroxide, which is preferably reacted
in a mixed aqueous-alcoholic solvent, preferably at elevated
temperature, e.g. 80-90.degree. C. The optional alkylation step can
be effected using known procedures, for example in the presence of
an inorganic or organic base, for example in an aqueous, organic or
mixed aqueous-organic solvent. Alkylation may be carried out at
sub-ambient temperature or, more conveniently, at ambient or
elevated temperature. Preferred alkylating agents are alkyl iodides
or, especially, dialkyl sulfates. Preferred bases are alkali metal
hydroxides in aqueous alcoholic solvents, especially aqueous
ethanol.
[0051] Compounds of formula IX may be prepared by reacting a
compound of formula ##STR11## with cyanoacetic acid or an
amide-forming derivative thereof such as an ester or acid halide
thereof, preferably the acid or its ethyl ester. The reaction may
be effected using known procedures, for example in an organic
solvent, preferably an anhydride such as acetic anhydride. The
reaction temperature may be ambient or, more conveniently, elevated
temperature, e.g. 65 to 70.degree. C.
[0052] Compounds of formula X may be prepared using conventional
procedures, for example from an isocyanate R.sup.2NCO by reaction
with gaseous or aqueous ammonia or from an amine R.sup.2NH.sub.2 by
reaction with a metal cyanate, for example as hereinafter described
in the Examples.
[0053] Compounds of formula VIII where R.sup.1 is alkyl optionally
substituted by hydroxy, alkoxy or alkylthio and R.sup.2 is as
hereinbefore defined other than hydrogen, may be prepared by
hydrogenolysis of a compound of formula ##STR12## where R.sup.1 is
alkyl optionally substituted by hydroxy, alkoxy or alkylthio,
R.sup.2 is as hereinbefore defined other than hydrogen and Ar is
phenyl optionally substituted by one or more
C.sub.1-C.sub.4-alkoxy, preferably methoxy, groups. The
hydrogenolysis may be carried out in a known manner, e.g. by
treatment with hydrogen or a source of hydrogen and a metal
catalyst such as a platinum or, preferably, palladium catalyst. The
reaction may be carried out in an organic solvent. The reaction
temperature may be ambient or elevated. Preferably hydrogenolysis
is effected using palladium black in formic acid, e.g. as
hereinafter described in the Examples.
[0054] Compounds of formula XI may be prepared by reacting a
compound of formula ##STR13## where R.sup.1 and R.sup.2 are as
hereinbefore defined for formula XI, with a compound of formula
ArCH.sub.2NH.sub.2 where Ar is as hereinbefore defined. The
reaction may be carried out in a known manner, e.g. in an organic
solvent, preferably an alcohol such as n-butanol, at ambient or
elevated temperature, or analogously as hereinafter described in
the Examples.
[0055] Compounds of formula XII may be prepared by reacting a
compound of formula ##STR14## where R.sup.1 is as hereinbefore
defined for formula XI, with a compound of formula R.sup.2X where
R.sup.2 is as hereinbefore defined for formula XI and X is halogen
or hydroxy, where X is hydroxy, the reaction being carried out in
the presence of activating reagents, preferably an azodicarboxylate
such as di-t-butyl azodicarboxylate together with a
triarylphosphine such as diphenylpyridylphosphine. The reaction may
be carried out in an organic solvent, preferably an ether such as
dioxan. The reaction temperature may be sub-ambient or, preferably,
ambient or elevated temperature. The reaction may be carried out
using the procedure of Mitsonobu, Synthesis 1981, 1, or analogously
as hereinafter described in the Examples. Compounds of formula XIII
are known or may be prepared by known procedures.
[0056] Compounds of formula VI may be prepared, for example, (i)
from benzaldehyde or a substituted benzadehyde using the procedure
of Dyke et al, Tetrahedron 1968, 24, 1467 or (ii) from an
optionally substituted, N-protected 1,2-dihydroisoquinoline by
reaction with a 2-oxo-carboxylic acid using the procedure of Dyke
et al, Tetrahedron 1968, 24, 1467, optionally followed by
conversion of the resulting carboxylic acid into a methyl ester and
then an alkali metal salt using the procedure of J. March, Advanced
Organic Chemistry, 4th Edition, Wiley, New York, 1992, pages 393
and 378 or (iii) from an optionally substituted quinoline or
isoquinoline by reaction with a hydride reducing agent followed by
a 2-oxo-carboxylic ester using the procedure of Minter et al, J.
Org. Chem. 1988, 53, 2653 or (iv) by introducing substituents onto
the N-containing ring of an acid of formula VI using the procedures
of Janin and Biagani, Tetrahedron 1993, 39, 10305, or Ford et al,
J. Med. Chem, 1985, 28, 164.
[0057] Certain preferred compounds of formula VI may be prepared
by
[0058] (i) the reaction sequence ##STR15## where R.sup.4, R.sup.9,
R.sup.10, R.sup.11, R.sup.12 and R.sup.13 are as hereinbefore
defined. Steps (a) to (c) may be carried out in a known manner,
e.g. using the procedure of Dyke et al, Tetrahedron 1968, 24, 1467,
or analogously as hereinafter described in the Examples;
[0059] (ii) the reaction sequence ##STR16## where R.sup.4, R.sup.9,
R.sup.10, R.sup.11, R.sup.12 and R.sup.13 are as hereinbefore
defined. Steps (d) to (g) may be carried out in a known maner, e.g.
step (d) using the procedure of Katayama et al, Chem. Pharm. Bull,
1980, 28, 2226, step (e) using the procedure of Dyke et al,
Tetrahedron 1968, 24, 1467 and steps (f) and (g) using the
procedure of J. March, Advanced Organic Chemistry, 4th Edition,
Wiley, New York, 1992, pages 393 and 378, or analogously as
hereinafter described in the Examples;
[0060] (iii) the reaction ##STR17## e.g. by treatment of XVIII with
a hydride reducing agent, followed by a 2-oxo-carboxylic ester,
using the procedure of Minter et al, J. Org. Chem. 1988, 53, 2653,
or analogously as described hereinafter in the Examples;
[0061] (iv) for the preparation of compounds of formula VI in which
R.sup.5 is a 4-isoquinolinyl group substituted in the 1-position,
the reaction sequence ##STR18## where R.sup.4, R.sup.6, R.sup.7,
R.sup.9, R.sup.10, R.sup.11, R.sup.12 and R.sup.13 are as
hereinbefore defined. Steps (h) to (k) may be carried out in a
known manner, e.g. steps (h) to (j) using the procedure of Janin
and Biagni, Tetrahedron, 1993, 39, 10305 and step (k) using the
procedure of J. March, Advanced Organic Chemistry, 4th Edition, New
York, 1992, page 378 or analogously as hereinafter described in the
Examples;
[0062] (v) for the preparation of compounds of formula VI in which
R.sup.5 is an isoquinolinyl group of formula III in which R.sup.8
is cyano, the reaction sequence ##STR19## where R.sup.4, R.sup.9,
R.sup.10, R.sup.11, R.sup.12, and R.sup.13 are as hereinbefore
defined. Steps (l) to (n) may be carried out in a known manner,
e.g. steps (l) and (m) using the procedure of Ford et al, J. Med.
Chem., 1985, 28, 164 and step (n) using the procedure of J. March,
op.cit., page 378;
[0063] (vi) for the preparation of compounds of formula VI in which
R.sup.5 is an oxodihydroisoquinolinyl group, the reaction sequence
##STR20## where R.sup.4, R.sup.9, R.sup.10, R.sup.11, R.sup.12 and
R.sup.13 are as hereinbefore defined. Steps (o) and (p) may be
carried out in a known manner, e.g. using the procedure of
Holzgrabe, Arch. Pharm. (Weinheim, Ger.), 1988, 321, 767, or
analogously as hereinafter described in the Examples;
[0064] (vii) for preparation of compounds of formula VI where
R.sup.5 is a quinolinyl group, the reaction ##STR21## where
R.sup.4, R.sup.9, R.sup.10, R.sup.11, R.sup.12 and R.sup.13 are as
hereinbefore defined, which may be carried out in a known manner,
e.g. by treatment with a strong base, preferably an alkali metal
dialkylamide such as lithium diisopropylamide, followed by
treatment with carbon dioxide, e.g. using the procedure of using
Brown and Curless, Tetrahedron Lett., 1986, 27, 6005, or
analogously as hereinafter described in the Examples.
[0065] (viii) for the preparation of compounds of formula VI where
R.sup.5 is a 4-isoquinolinyl group, ##STR22## ##STR23## where
R.sup.8, R.sup.10, R.sup.11, R.sup.12 and R.sup.13 are as
hereinbefore defined. Steps (q) to (w) may be carried out in a
known manner; e.g. step (q) by treatment with a
carboxyethyltriarylphosphonium ylid, preferably
carboxyethyltriphenylphosphonium ylid in an organic solvent,
preferably an ether or hydrocarbon, especially toluene, at
sub-ambient, elevated or, preferably, ambient temperature; step (r)
by treatment with nitromethane in the presence of an inorganic or,
preferably, amine base, especially tetramethylguanidine, for
example in the presence of a solvent or, preferably, in the absence
of a solvent, at sub-ambient, ambient or, preferably, elevated
temperature, e.g. 60-80.degree. C.; step (s) by treatment with a
reducing agent, preferably a tin (II) salt, especially tin (II)
chloride hydrate, in an aqueous or, preferably, organic solvent,
preferably an alcohol such as ethanol, at sub-ambient, ambient or,
preferably, elevated temperature, e.g. under reflux; step (t) by
treatment with an acid halide or anhydride, preferably the acid
chloride, of the acid R.sup.8COOH, at elevated or, preferably,
sub-ambient or ambient temperature, e.g. 0.degree. C. to ambient
temperature, in an aqueous or, preferably, organic solvent,
especially a chlorinated solvent such as dichloromethane,
preferably in the presence of a base, especially an amine such as
triethylamine; step (u) by treatment with a phosphorus (V) halide
or oxyhalide, preferably phosphorous pentachloride or phosphorus
oxychloride, preferably in an organic solvent such as a hydrocarbon
or nitrile, especially acetonitrile preferably at ambient or,
especially, elevated temperature, e.g. under reflux; step (v) by
treatment with a noble metal, preferably palladium, catalyst,
preferably in an organic solvent, especially a hydrocarbon such as
decalin, preferably at elevated temperature, e.g. under reflux;
step (w) by treatment with an alkali metal hydroxide, preferably
lithium or sodium hydroxide, in organic, aqueous or mixed
organic-aqueous solvent, preferably THF-water, at sub-ambient,
elevated or, preferably, ambient temperature; specific methods for
steps (q) to (w) being as hereinafter described in the
Examples.
[0066] (ix) the reaction sequence ##STR24## where R.sup.9,
R.sup.11, R.sup.12 and R.sup.13 are as hereinbefore defined, Ac is
an acyl group, and Y is halogen. Steps (x) to (za) may be effected
in a known manner, e.g. step (x) by reaction with a halogenation
agent, e.g. bromine or a N-halosuccinimide, preferably
N-chlorosuccinimide, e.g. as described in J. March, op.cit., page
531; step (y) by reaction with a reducing agent, e.g. a metal
hydride, in the presence of an acylating agent, e.g. acetic
anhydride, e.g. as described in Katayama et al, op.cit; step (z) by
reaction with a 2-oxocarboxylic acid, preferably glyoxylic acid, in
the presence of a mineral acid, e.g. as described in Dyke et al,
Tetrahedron 1968, 24, 1467; and step (za) by treatment with a
reducing agent, e.g. as described in J. March et al, op.cit, page
566; or analogously as described hereinafter in the Examples.
[0067] Certain compounds of formula V are novel, including
Intermediates 1 to 10 as described hereinafter. Certain compounds
of formula VI are novel, including Intermediates 20 to 48 as
described hereinafter.
[0068] Process variant (b) may be carried out in a known manner,
for example by reacting a compound of formula I where R.sup.3 is
hydrogen with an appropriate alkylating agent, preferably an alkyl
iodide or dialkyl sulfate, such as a compound of formula R.sup.3I
or (R.sup.3).sub.2SO.sub.4 where R.sup.3 is C.sub.1-C.sub.4-alkyl.
The reaction may be conducted in the presence of an inorganic or
organic base, for example in an aqueous, organic or mixed
aqueous-organic solvent. Alkylation may be carried out at
sub-ambient temperature or, more conveniently, at ambient or
elevated temperature. Preferred bases are alkali metal carbonates.
Preferred solvents are organic dipolar aprotic solvents, especially
N,N-dimethylformamide.
[0069] Process variant (c) may be effected using known
sulfonylation procedures, e.g. in the presence of an organic or
inorganic base, preferably a tertiary organic base such as
pyridine. The reaction temperature may be sub-ambient, ambient or,
preferably, elevated. Preferred procedures are as hereinafter
described in the Examples.
[0070] Process variant (d) may be effected using known procedures,
e.g. by treating a compound of formula I wherein R.sup.2 is alkenyl
with a hydroborating agent, followed by oxidative basic work-up.
Hydroboration may be carried out at sub-ambient or, more
conveniently, at ambient or elevated, temperature. Preferred
hydroborating agents are dialkylboranes such as
9-borabicyclo[2.2.0]nonane, which are preferably reacted under
reflux. Oxidative work-up is preferably conducted with hydrogen
peroxide and an alkali metal hydroxide, preferably sodium
hydroxide. The work-up temperature is preferably 40-60.degree.
C.
[0071] Process variant (e) may be carried out using conventional
esterification procedures, e.g. by reacting the compound of formula
I wherein R.sup.2 is hydroxy with a carboxylic acid or halide
thereof, preferably an acid chloride, in the presence of an organic
or inorganic base, at sub-ambient or, preferably, ambient or
elevated (e.g. 40-60.degree. C.) temperature. Preferred bases are
organic tertiary bases such as pyridine.
[0072] Process variant (f) may be carried out using known
procedures for conversion of acylamino into amino, e.g. by
treatment with a mineral acid such as sulphuric or, preferably,
hydrochloric acid. The reaction is preferably carried out in a
mixed aqueous-organic solvent such as aqueous ethanol. The reaction
temperature is conveniently ambient or, preferably, elevated
temperature, especially reflux temperature.
[0073] Process variant (g) may be effected using known dealkylation
methods, e.g. by reaction with HBr or HI, usually at elevated
temperature, preferably by heating with concentrated hydrobromic
acid, e.g. as hereinafter described in the Examples.
[0074] Process variant (h) may be effected using known halogenation
procedures, e.g. by reaction with bromine or chlorine in a solvent
such as acetic acid. The reaction is conveniently carried at
ambient temperature, e.g. as hereinafter described in the
Examples.
[0075] Process variant (i) may be effected using known procedures
for the Simmons Smith reaction, e.g. by reaction with diethyl zinc
and chloroiodomethane. The reaction is usually carried out in an
organic solvent, preferably a halohydrocarbon. The reaction is
suitably carried out at ambient temperature, e.g. as hereinafter
described in the Examples.
[0076] Compounds of formula I in free form may be converted into
salt form, and vice versa, in a conventional manner. The compounds
in free or salt form can be obtained in the form of hydrates or
solvates containing a solvent used for crystallization. The
compounds of formula I in free or salt form can be recovered from
reaction mixtures in a conventional manner. Isomer mixtures can be
separated into individual isomers, e.g. enantiomers, in a
conventional manner, e.g. by fractional crystallization.
[0077] Compounds of formula I in free or pharmaceutically
acceptable salt form, hereinafter referred to alternatively as
agents of the invention, are useful as pharmaceuticals. In
particular, they are inhibitors of cyclic
guanosine-3',5'-monophosphate phosphodiesterases (cGMP PDEs),
especially PDE5. Agents of the invention are selective PDE5
inhibitors; in particular, they exhibit good selectivity for
inhibition of PDE5 relative to inhibition of other
phosphodiesterases, particularly PDE1 and PDE6, indicating a low
side-effect profile. Furthermore agents of the invention have an
appropriate duration of action and many have a rapid onset of
action. The inhibiting properties of agents of the invention may be
demonstrated in the following test procedure:
[0078] PDE5 Assay: A 10 mM solution of a test compound in DMSO is
diluted 100-fold with aqueous 20% v/v DMSO to give a 100 .mu.M
stock solution, which is further diluted with aqueous 20% v/v DMSO
to give ten solutions having concentrations from 10 .mu.M to
0.00051 .mu.M. 10 .mu.L of each of these solutions is transferred
to a selected well of a 96-well Optiplate microtitre plate (ex
Packard). To determine total binding, 10 .mu.l of aqueous 20% v/v
DMSO is added to other selected wells. To determine non-specific
binding, a 10 mM solution of sildenafil in 100% DMSO is diluted
20-fold with aqueous 20% v/v DMSO and 10 .mu.l of the resulting
solution is added to further selected wells of the Optiplate plate.
To all wells containing test compound solution, aqueous DMSO or
sildenafil solution is added 80 .mu.l of Assay Mix, prepared by
mixing PDE Assay Buffer (2 ml), an aqueous solution of bovine serum
albumin (BSA) containing 5 mg BSA/ml (2 ml), an aqueous 75 .mu.M
solution of cGMP sodium salt (0.2 ml), 3H-cGMP (ex Amersham, 10
.mu.l) and distilled water (11.8 ml). (The PDE Assay Buffer is
prepared by dissolving Tris-base (7.56 g) in water (800 ml), adding
1M aqueous MgCl.sub.2 (10.325 ml) and 0.5 M EDTA (4.25 ml),
adjusting the pH to 7.5 with 1N hydrochloric acid and making up to
1 litre with water). A solution of human PDE5, partially purified
from human platelets (11 .mu.l, containing 0.017 units of PDE5 per
ml, where 1 unit hydrolyses 1.0 .mu.mole of 3',5'-cyclic GMP to
5'-GMP per minute at pH 7.5 at 37.degree. C.), in 20 mM Hepes, pH
7.4, 100 mM sodium chloride, 10% v/v glycerol, 1 mM benzamidine and
2 mM dithiotherietol, is diluted 200-fold, with Enzyme Buffer
prepared by adding 0.5M EDTA (2 ml) to a solution of Tris-Base
(1.21 g) in water (800 ml), adjusting the pH to 7.5 with 1N HCl and
making up to 1 litre with water. The diluted PDE5 solution (10
.mu.l) is added to all wells containing test compound, aqueous DMSO
or sildenafil solution. The plate is incubated at room temperature
for 1 hour. 50 .mu.l of a suspension of 500 mg PDE Yttrium silicate
SPA beads (ex Amersham) in 28 ml water is added to each of the
wells and the plate is incubated for a further 20 minutes and then
sealed using Top Seal-S (ex Packard) according to the
manufacturer's instructions. The resulting scintillations are
counted using a Canberra Packard Top Count (1 minute per well), as
a measure of the extent to which binding of PDE5 to the beads is
inhibited. The concentration of test compound at which 50%
inhibition of PDE5 binding to the beads occurs (IC.sub.50) is
determined from concentration-inhibition curves in a conventional
manner.
[0079] Compounds of the Examples hereinbelow have IC.sub.50 values
of the order of from 0.0005 .mu.M to 10 .mu.M in the above assay.
For example, the compounds of Examples 7, 10, 15, 35, 45, 49, 55,
60, 68 and 70 have IC.sub.50 values of 0.007 .mu.M, 0.01 .mu.M,
0.006 .mu.M, 0.010 .mu.M, 0.002 .mu.M, 0.0037 .mu.M, 0.0055 .mu.M,
0.0028 .mu.M, 0.007 .mu.M and 0.009 .mu.M respectively in the above
assay.
[0080] Having regard to their inhibition of PDE5, agents of the
invention are useful in the treatment of conditions which are
mediated by PDE5. Treatment in accordance with the invention may be
symptomatic or prophylactic.
[0081] Accordingly, agents of the invention are useful in the
treatment of sexual dysfunction, including male erectile
dysfunction and female sexual dysfunction, premature labour,
dysmenorrhoea, benign prostatic hyperplasia, bladder outlet
obstruction, incontinence, stable, unstable and variant
(Prinzmetal) angina, hypertension, pulmonary hypertension,
congestive heart failure, atherosclerosis, conditions of reduced
blood vessel patency, e.g. post-percutaneous transluminal coronary
angioplasty, peripheral vascular disease, bronchitis, asthma,
allergic rhinitis, glaucoma, tinnitus, diseases characterised by
disorders of gut motility, e.g. irritable bowel syndrome,
pre-eclampsia, Kawasaki's syndrome, nitrate tolerance, multiple
sclerosis, peripheral diabetic neuropathy, stroke, Alzheimer's
disease, acute respiratory failure, psoriasis, skin necrosis,
cancer, metastasis, baldness, nutcracker oesophagus, anal fissure
and hypoxic vasoconstriction.
[0082] Agents of the invention are of particular interest for use
in the treatment of sexual dysfunction, especially male erectile
dysfunction.
[0083] In accordance with the foregoing, the invention also
provides a method for the treatment of a condition mediated by
PDE5, for example a condition mentioned hereinbefore, particularly
sexual dysfunction, especially male erectile dysfunction, which
comprises administering to a subject, particularly a human subject,
in need thereof an effective amount of a compound of formula I in
free form or in the form of a pharmaceutically acceptable salt. In
another aspect, the invention provides a compound of formula I, in
free form or in the form of a pharmaceutically acceptable salt, for
use in the manufacture of a medicament for the treatment of a
condition mediated by PDE5, for example a condition as mentioned
hereinbefore, particularly sexual dysfunction, especially male
erectile dysfunction.
[0084] Agents of the invention may be administered by any
appropriate route, e.g. orally, for example in the form of a
tablet, a capsule, a solution or a suspension; parenterally, for
example intravenously, intracavernosally, intramuscularly or
subcutaneously; intranasally, for example in the form of an aerosol
or aqueous dispersion; by inhalation, for example as an aerosol, a
nebulized aqueous dispersion or a dry powder; buccally or
sublingually, for example in the form of a tablet or lozenge;
topically to the skin, for example in the form of a cream or
ointment; or rectally, e.g. as a suppository.
[0085] In a further aspect the invention provides a pharmaceutical
composition comprising as active ingredient a compound of formula I
in free form or in the form of a pharmaceutically acceptable salt,
optionally together with a pharmaceutically acceptable diluent or
carrier therefor. Such compositions may be prepared using
conventional excipients and techniques known in the galenic art.
Thus oral dosage forms may include tablets and capsules.
Compositions for inhalation may include aerosol or other atomizable
formulations or dry powder formulations. Compositions for topical
administration to the skin may include creams, ointments or
gels.
[0086] The agents of the invention may also be used in combination
with other PDE5 inhibitors or with other therapeutic agents
suitable for the treatment of sexual dysfunction, particularly male
erectile dysfunction, e.g. .alpha. adrenergic receptor antagonists
such as phentolamine methanesulfonate, dopamine D2 agonists such as
apomorphine or NO donors such as L-arginine. An agent of the
invention may be mixed with the co-therapeutic agent in a
pharmaceutical composition or it may be administered separately,
before, simultaneously with or after the co-therapeutic agent.
[0087] This invention is illustrated by the following Examples.
[0088] Intermediates of formula V are prepared as follows:
[0089] Intermediate 1
[0090] Methallylamine (211 g, 2.97 mol) is added to a solution of
concentrated hydrochloric acid (250 ml) in water (1.91), followed
by portionwise addition of potassium cyanate (240 g, 2.97 mol). The
reaction is then heated for 2 hours at 80.degree. C., prior to
cooling and evaporation to afford (2-methyl-allyl)-urea (244.5 g),
mp 114-115.degree. C. The urea (268 g, 2.35 mol) is added to a
solution of cyanoacetic acid (220 g, 2.59 mol) in acetic anhydride
(536 ml) and the reaction is heated at 70.degree. C. for 1 hour,
cooled to 0.degree. C. and diluted with ether. The resultant solid
is collected by filtration, washed with ether, suspended in water
(2.21) and heated to 75.degree. C. 2M aqueous sodium hydroxide
solution is then added portionwise over 30 min to maintain pH
between 8 and 9.5. The reaction is cooled to room temperature,
treated with acetic acid (12 ml), further cooled to 10.degree. C.
and the resultant solid is collected by filtration, washed with
cold water and dried to afford
6-amino-1-(2-methyl-allyl)-1H-pyrimidine-2,4-dione, mp
267-269.degree. C. The uracil (253 g, 1.40 mol) is added to a
solution of sodium hydroxide (123 g, 3.07 mol) in water (2.5 l) and
allowed to exotherm then cooled to 20.degree. C. Dimethyl sulfate
(196 ml, 2.06 mol) is added portionwise over 1 hour. After standing
overnight, the reaction is cooled to 5.degree. C. and the solid
collected by filtration to give
6-amino-3-methyl-1-(2-methyl-allyl)-1H-pyrimidine-2,4-dione, mp
162-163.degree. C. The methyluracil (165 g, 0.85 mol) is suspended
in water (1.55 l) and concentrated hydrochloric acid (72 ml). A
solution of sodium nitrite (58.4 g, 0.85 mol) in water (117 ml) is
then added dropwise over 30 minutes and the reaction is stirred at
20.degree. C. for 3 hours. The solid is collected by filtration,
washed successively with water, methanol and ether to afford
6-amino-3-methyl-1-(2-methyl-allyl)-5-nitroso-1H-pyrimidine-2,4-dione,
mp 213.degree. C. (dec). The nitrosouracil (190 g, 0.85 mol) is
suspended in water (950 ml), heated to 85.degree. C. and sodium
dithionite (85%, 347.2 g, 1.69 mol) is added portionwise. After
cooling to room temperature, the solid is collected by filtration
to afford
5,6-diamino-3-methyl-1-(2-methyl-allyl)-1H-pyrimidine-2,4-dione, mp
152-153.degree. C.
[0091] Intermediate 2
[0092] Using the general procedure for Intermediate 1,
(3-nitrobenzyl)-urea [J. Med. Chem. 1996, 39, 1924] is converted
into 6-amino-3-methyl-1-(3-nitro-benzyl)-1H-pyrimidine-2,4-dione,
[M-H].sup.-275. A suspension of this compound (4.88 g, 17.7 mmol)
and 10% Pd/C (0.484 g) in ethanol (200 ml) is hydrogenated at 1
atmosphere for 1.5 hours. The reaction mixture is filtered through
a celite plug and evaporated to give
6-amino-1-(3-amino-benzyl)-3-methyl-1H-pyrimidine-2,4-dione acetic
acid salt [M-H].sup.-245. Acetic anhydride (1.85 ml, 19.57 mmol) is
added to a cooled (0.degree. C.) suspension of
6-amino-1-(3-amino-benzyl)-3-methyl-1H-pyrimidine-2,4-dione acetic
acid salt (5.01 g, 16.35 mmol) in pyridine (50 ml). The reaction
mixture is warmed to room temperature, stirred for 6 hours and the
solvent evaporated. The residue is triturated with water and the
solid collected by filtration and dried to afford
N-[3-(6-amino-3-methyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-ylmethyl)-phe-
nyl]-acetamide, .sup.1H NMR (400 MHz, DMSO): .delta.: 2.00 (s 3H),
3.09 (s 3H), 4.72 (s 1H), 5.02 (s 2H), 6.75 (s 2H), 6.88 (d J 6
1H), 7.25 (t J 6 1H), 7.30 (s 1H), 7.55 (d J 6 1H). Using the
general procedure for Intermediate 1, this compound is converted
into
N-[3-(5,6-diamino-3-methyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-ylmethyl)-
-phenyl]-acetamide [MH].sup.+304.
[0093] Intermediate 3
[0094] Using the general procedure for Intermediate 1,
(4-nitro-benzyl)-urea [J. Med. Chem. 1996, 39, 1924] is converted
into 6-amino-3-methyl-1-(4-nitro-benzyl)-1H-pyrimidine-2,4-dione,
[MH].sup.+277. A solution of calcium chloride (4.94 g, 45 mmol) in
water (100 ml) is added to a solution of
6-amino-3-methyl-1-(4-nitro-benzyl)-1H-pyrimidine-2,4-dione (19.08
g, 69.0 mmol) in acetic acid (300 ml). Zinc dust (58.8 g, 900 mmol)
is then added portionwise with external cooling. The reaction is
stirred at room temperature for 1.5 hours, filtered through a
celite plug and washed successively with ethanol and acetic acid.
Evaporation of the combined filtrate and washings affords
6-amino-1-(4-amino-benzyl)-3-methyl-1H-pyrimidine-2,4-dione acetic
acid salt, [M-3H].sup.-243. Acetic anhydride (7.2 ml, 76.0 mmol) is
added to a cooled (0.degree. C.) suspension of
6-amino-1-(4-amino-benzyl)-3-methyl-1H-pyrimidine-2,4-dione acetic
acid salt (17.0 g, 69.0 mmol) in pyridine (260 ml). The reaction
mixture is warmed to room temperature, stirred for 6 hours and the
solvent evaporated. The residue is triturated with water and the
solid collected by filtration and dried to afford
N-[4-(6-amino-3-methyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-ylmethyl)-phe-
nyl]-acetamide, [MH].sup.+289. Using the general procedure for
Intermediate 1, this compound is converted into
N-[4-(5,6-diamino-3-methyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-ylmethyl)-
-phenyl]-acetamide, [MH].sup.+304.
[0095] Intermediate 4
[0096] To a cooled (0.degree. C.) slurry of 6-chloromethyluracil
(2.0 g, 12 mmol) in THF/dioxan (1:1, 16 ml) is added
2-pyridyldiphenylphosphine (3.60 g, 13.7 mmol) and
cyclobutanemethanol (1.3 ml, 13.8 mmol), followed by
di-t-butylazodicarboxylate (3.15 g, 13.7 mmol). The reaction is
stirred overnight at ambient temperature, treated with 4M HCl in
dioxan (15 ml) and evaporated. The residue is taken up in
dichloromethane, washed with 3.5M HCl, dried over magnesium sulfate
and evaporated. The crude product is purified by flash
chromatography (100:1 dichloromethane-methanol elution) to afford
6-chloro-1-cyclobutylmethyl-3-methyl-1H-pyrimidine-2,4-dione,
.sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 1.70-2.0 (m 6H), 2.60 (m
1H), 3.20 (s 3H), 4.00 (d J 7 2H), 5.78 (s 1H), which is dissolved
in n-butanol (50 ml). Veratrylamine (4 ml, 26.5 mmol) is added and
the reaction heated to reflux for 16 hours. The solvent is
evaporated and the residue taken into dichloromethane, washed with
1M aqueous HCl, dried over magnesium sulfate and evaporated. The
crude product is purified by flash chromatography (50:1
dichloromethane-methanol elution) to afford
1-cyclobutylmethyl-6-(3,4-dimethoxy-benzylamino)-3-methyl-1H-pyrimidine-2-
,4-dione, .sup.1H NMR (400 MHz, CDCl.sub.3) d 1.60-1.80 (m 4H),
1.80-2.00 (m 2H), 2.50 (m 1H), 3.21 (s 3H), 3.80 (s 6H), 3.85 (d J
7 2H), 4.11 (d J 5 1H), 4.25 (m 1H), 4.84 (s 1H), 6.74 (s 1H), 6.80
(s 2H), which is dissolved in formic acid (50 ml) and Pd black
(0.26 g) added. The reaction is heated at 40.degree. C. for 21
hours, filtered through Celite, evaporated and purified by
preparative HPLC to afford
6-amino-1-cyclobutylmethyl-3-methyl-1H-pyrimidine-2,4-dione,
M.sup.+209, which is converted using the general procedure for
Intermediate 1 into
5,6-diamino-1-cyclobutylmethyl-3-methyl-1H-pyrimidine-2,4-dione,
HPLC retention time 0.17 mins (30-95% acetonitrile water gradient
in 4 minutes).
[0097] Intermediate 5
[0098]
5,6-Diamino-3-methyl-1-(tetrahydro-furan-2-ylmethyl)-1H-pyrimidine-
-2,4-dione, mp 115-116.degree. C., is prepared from
(tetrahydro-furan-2-ylmethyl)-urea (Collect. Czech. Chem. Commun.
1972, 37, 2786) using the general procedure for Intermediate 1.
[0099] Intermediate 6
[0100]
5,6-Diamino-3-methyl-1-(2-methyl-butyl)-1H-pyrimidine-2,4-dione, mp
163-165.degree. C., is prepared using the general procedure for
Intermediate 1.
[0101] Intermediate 7
[0102] 5,6-Diamino-1-hexyl-3-methyl-1H-pyrimidine-2,4-dione, is
prepared from 6-amino-1-hexyl-1H-pyrimidine-2,4-dione (J. Med.
Chem. 1993, 36, 1465) using the general procedure for Intermediate
1, HPLC retention time (0-95% acetonitrile water gradient over 8
minutes) 6.01 min.
[0103] Intermediate 8
[0104]
5,6-Diamino-1-(3,4-dimethoxy-benzyl)-3-methyl-1H-pyrimidine-2,4-di-
one, [M-H].sup.-305, is prepared from (3,4-dimethoxy-benzyl)-urea
(Farmaco, Ed. Sci. 1977, 32, 813) using the general procedure for
Intermediate 1.
[0105] Intermediate 9
[0106]
5,6-Diamino-1-benzo[1,3]dioxol-5-ylmethyl-3-methyl-1H-pyrimidine-2-
,4-dione, mp 183-186.degree. C., is prepared using the general
procedure for Intermediate 1.
[0107] Intermediate 10
[0108]
5,6-Diamino-1-(2,4-dichloro-benzyl)-3-methyl-1H-pyrimidine-2,4-dio-
ne, is prepared using the general procedure for Intermediate 1,
.sup.1H NMR (400 MHz DMSO-d6) .delta. 3.16 (s 3H), 5.05 (s 2H),
6.18 (s 2H), 6.82 (d J 9 1H), 7.38 (d J 9 1H), 7.62 (s 1H).
[0109] Other Intermediates of formula V are prepared according to
literature references as indicated below: TABLE-US-00001 No.
R.sup.1 R.sup.2 Reference 11 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2
(1) 12 H CH.sub.3 (2) 13 CH.sub.3 CH.sub.2.dbd.CHCH.sub.2 (3) 14
CH.sub.3 ##STR25## (1) 15 CH.sub.3 (CH.sub.3).sub.3CCH.sub.2 (1) 16
(CH.sub.3).sub.2CHCH.sub.2 (CH.sub.3).sub.2CHCH.sub.2 (1) 17
CH.sub.3 ##STR26## (1) 18 H CH.sub.3CH.sub.2CH.sub.2 (2) 19
CH.sub.3 ##STR27## (4) References: (1) Eur. J. Med. Chem. 1990, 25,
653 (2) J. Med. Chem. 1996, 39, 2 (3) FR 2 531 085 (4) Eur. J. Med.
Chem.-Chim. Ther. 1974, 9, 313
[0110] Intermediates of formula VI are prepared as follows:
[0111] Intermediate 20
[0112] A mixture of 3-(3,4-dimethoxy-phenyl)-5-nitro-pentanoic acid
ethyl ester [J. Med. Chem, 1989, 32, 1450] (0.50 g, 1.68 mmol) and
tin(II)chloride dihydrate (1.90 g, 8.4 mmol) in ethanol (10 ml) is
heated to reflux for 2 hours, cooled to ambient temperature and
evaporated. The crude product is taken into dichloromethane (15
ml), cooled to 0.degree. C. and triethylamine (5 ml) added,
followed by 3,5-dimethoxybenzoyl chloride (0.404 g, 2.02 mmol). The
reaction is stirred at ambient temperature overnight and then
evaporated, taken into ethyl acetate, washed with water and dried
over sodium sulfate. Evaporation and purification by flash column
chromatography (1:1 hexane-ethyl acetate elution) affords
4-(3,5-dimethoxy-benzoylamino)-3-(3,4-dimethoxy-phenyl)-butyric
acid ethyl ester, [MH].sup.+ 432. This intermediate (0.200 g, 0.46
mmol) is taken into acetonitrile (8 ml) and phosphorus oxychloride
(.sup.0.211 g, 1.38 mmol) added, prior to heating at reflux for 3
hours. After evaporation of the solvent, the residue is taken into
ethyl acetate, washed with saturated aqueous sodium carbonate,
dried over sodium sulfate and evaporated to afford
[1-(3,5-dimethoxy-phenyl)-6,7-dimethoxy-3,4-dihydro-isoquinolin-4-yl]-ace-
tic acid ethyl ester, [MH].sup.+414. This intermediate (0.50 g,
1.21 mmol) is dissolved in decalin (10 ml) and 10% Pd/C (50 mg)
added. The reaction is heated at 190.degree. C. for 2.5 hours, then
cooled to ambient temperature and diluted with dichloromethane.
After filtration through Celite, the combined filtrate and washings
are evaporated to afford
[1-(3,5-dimethoxy-phenyl)-6,7-dimethoxy-isoquinolin-4-yl]-acetic
acid ethyl ester, .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 1.18 (t
J 7 3H), 3.78 (s 6H), 3.80 (s 3H), 3.90 (s 2H), 3.99 (s 3H), 4.10
(q J 7 2H), 6.50 (d J 0.5 1H), 6.75 (d J 0.5 2H), 7.20 (s 1H), 7.36
(s 1H), 8.40 (s 1H). This intermediate (0.30 g, 0.73 mmol) is
dissolved in methanol (10 ml), 1M aqueous lithium hydroxide (0.80
ml, 0.80 mmol) is added and the reaction stirred overnight at
ambient temperature. After evaporation of the methanol, pH of the
residual solution is adjusted to 7 with 1M aqueous HCl and the
resultant solid collected by filtration and dried to afford
[1-(3,5-dimethoxy-phenyl)-6,7-dimethoxy-isoquinolin-4-yl]-acetic
acid.
[0113] Intermediate 21
[0114] A mixture of 3-isopropoxy4-methoxy-benzaldehyde (3.9 g, 20
mmol) and (ethoxycarbonylmethylene)triphenylphosphorane (6.96 g. 20
mmol) in toluene (100 ml) is heated at reflux for 2 hours, cooled
to ambient temperature and evaporated. The crude product is taken
in to dichloromethane and eluted through a pad of silica to afford
(E)-3-(3-isopropoxy-4-methoxy-phenyl)-acrylic acid ethyl ester, TLC
R.sub.f 0.70 (1:1 hexane-ethyl acetate). This intermediate is
dissolved in nitromethane (10 ml), 1,1,3,3-tetramethylguanidine
(0.5 ml) is added and the reaction heated at 70.degree. C. for 36
hours. The solvent is evaporated, the residue is taken into ethyl
acetate and washed with 2N aqueous HCl, water and brine. After
drying over sodium sulfate and evaporation, the crude product is
purified by flash column chromatography (4:1 hexane-ethyl acetate
elution) to afford
3-(3-isopropoxy-4-methoxy-phenyl)-4-nitro-butyric acid ethyl ester,
.sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 1.20 (t J 7 3H), 1.38 (d
J 7 6H), 2.75 (d J 6 2H), 3.90 (m 1H), 4.10 (m 2H), 4.48-4.78 (m
3H), 6.75-6.86 (m 3H). This intermediate is converted into
[1-(3,5-diisopropoxy-phenyl)-6-isopropoxy-7-methoxy-isoquinolin-4-yl]-ace-
tic acid using the general procedure for Intermediate 20.
Characterised as the ethyl ester, [MH].sup.+496.
[0115] Intermediate 22
[0116] A solution of 3-ethoxy-4-methoxybenzaldehyde (3.6 g, 20
mmol) in ethanol (15 ml) is added to 2,2-dimethoxyethylamine (21
mmol) and the mixture heated at reflux for 2 hours. After cooling
to room temperature, sodium borohydride (0.794 g, 21 mmol) is added
and the mixture stirred at room temperature overnight. Ethanol is
removed by evaporation and water added, followed by extraction with
ethyl acetate. The organic extracts are combined, washed with
water, brine, dried over magnesium sulfate and evaporated to give
(2,2-dimethoxy-ethyl)-(3-ethoxy4-methoxy-benzyl)-amine,
[MH].sup.+270. The intermediate (2.70 g, 10 mmol) is suspended in
6N HCl (50 ml), glyoxylic acid (0.88 g, 12 mmol) is added and the
mixture heated for 1 hour at 100.degree. C. After cooling to room
temperature, methanol (30 ml) is added and the mixture filtered and
characterised as the methyl ester M.sup.+276. The filtrate is
treated with lithium hydroxide (10 mmol) in THF-methanol-water
overnight. After evaporation of the solvents, the crude product is
partitioned between water and dichloromethane. The aqueous phase is
washed with dichloromethane and evaporated to dryness to afford
(7-ethoxy-6-methoxy-isoquinolin-4-yl)-acetic acid lithium salt
which is used for xanthine formation without further
characterisation.
[0117] Intermediate 23
[0118] A solution of (6,7-dimethoxy-isoquinolin-4-yl)-acetic acid
ethyl ester (Tetrahedron 1973, 29, 3881) (1.668 g, 6.07 mmol) in
chloroform (20 ml) is treated portionwise with
m-chloroperoxybenzoic acid (1.153 g, 6.67 mmol) for 5 hours. The
reaction mixture is washed with saturated sodium bicarbonate and
brine, dried over MgSO.sub.4 and evaporated to afford
(6,7-dimethoxy-2-oxy-isoquinolin-4-yl)-acetic acid ethyl ester 1.71
g, 96%). The entire product is dissolved in chloroform (30 ml),
added to POCl.sub.3 (3 ml, 32.3 mmol) and heated at reflux for 2
hours. After evaporation, dichloromethane and ice water are added
and the mixture is basified with aqueous ammonia. The aqueous phase
is further extracted with dichloromethane, the combined organic
phases are washed with brine, dried over magnesium sulfate and
evaporated to afford
(1-chloro-6,7-dimethoxy-isoquinolin-4-yl)-acetic acid ethyl ester.
The chloro ester derivative (0.50 g, 1.6 mmol) is suspended in 2M
sodium hydroxide (15 ml). Ethanol (5 ml) is added and the solution
stirred at room temperature for 2 hours and the solvent evaporated.
Adjustment to pH 2 with concentrated hydrochloric acid affords a
solid which is collected by filtration and dried to afford
(1-chloro-6,7-dimethoxy-isoquinolin-4-yl)-acetic acid. .sup.1H NMR
(400 MHz, DMSO-d6) .delta.: 3.92 (s 3H), 3.96 (s 3H), 4.02 (s 2H),
7.31 (s 1H), 7.44 (s 1H), 8.04 (s 1H).
[0119] Intermediate 24
[0120] (2,2-Dimethoxy-ethyl)-(3-methoxy-benzyl)-amine (Tetrahedron,
1973, 29, 3881) is treated with pyruvic acid according to the
general procedure for Intermediate 22 to afford
2-(7-methoxy-isoquinolin-4-yl)-propionic acid hydrochloride salt,
mp 174-176.degree. C. Treatment with HCl gas in ethanol affords the
corresponding ethyl ester hydrochloride, mp 190-192.degree. C.,
which is then reacted sequentially with m-chloroperoxybenzoic acid
and phosphorus oxychloride as described for Intermediate 23 to
provide 2-(1-chloro-7-methoxy-isoquinolin-4-yl)-propionic acid
ethyl ester, mp 126-128.degree. C. This intermediate (47 g, 0.16
mol) is dissolved in ethanol (400 ml) and 2N sodium hydroxide (150
ml) added and the mixture heated at 60.degree. C. for one hour,
prior to evaporation of the solvent. Crystallisation from acetone
affords 2-(1-chloro-7-methoxy-isoquinolin-4-yl)-propionic acid, mp
167-168.degree. C.
[0121] Intermediate 25
[0122] Dimethyl sulfate (12.7 ml, 0.10 mol) is added portionwise to
2-(7-methoxy-2-oxy-isoquinolin-4-yl)-propionic acid ethyl ester (28
g, 0.10 mol) with an exotherm to 100.degree. C. The reaction is
maintained at this temperature for 2 hours, cooled to room
temperature and dissolved in water (50 ml). A solution of sodium
cyanide (15 g, 0.31 mol) in water (90 ml) is added over 30 minutes
with external cooling and the reaction is then stirred at room
temperature for 3 hours. The crude product is extracted with
chloroform, the chloroform extracts are washed with saturated
sodium bicarbonate, brine, dried over sodium sulfate and
evaporated. Crystallisation from 3N ethanolic HCl-ether affords
2-(1-cyano-7-methoxy-isoquinolin-4-yl)-propionic acid ethyl ester
hydrochloride, mp 89-98.degree. C. This compound is hydrolysed
converted to the acid as described for Intermediate 22 and used
directly crude for xanthine formation.
[0123] Intermediate 26
[0124] A solution of sodium triethylborohydride (1M THF, 12.7 ml,
12.7 mmol) is added dropwise to a solution of isoquinoline (1.64 g,
12.7 mmol) in THF (25 ml). The reaction is stirred at room
temperature for 1 hour, prior to dropwise addition of a solution of
ethyl glyoxalate (1.43 g, 13.9 mmol) in toluene (previously heated
at 110.degree. C. for 1.5 hours). After a further 4 hours at room
temperature, the reaction is cooled to 0.degree. C. and sodium
hydroxide (0.5M aqueous solution, 25.4 ml) followed by hydrogen
peroxide (30% aqueous solution, 12.7 ml) is added, followed by
stirring for 2 hours. The reaction is acidified with 1N HCl, washed
with ethyl acetate three times, the aqueous phase is reduced in
volume by evaporation and refrigerated overnight. The resultant
precipitate is collected by filtration and dried to afford
isoquinolin-4-yl-acetic acid hydrochloride salt, MH.sup.+ 188.
[0125] Intermediate 27
[0126] Excess morpholine is added to a suspension of
(1-chloro-6,7-dimethoxy-isoquinolin-4-yl)-acetic acid ethyl ester
(0.200 g, 0.65 mmol) in toluene (1 ml) and the mixture heated to
reflux until the starting material is consumed. After evaporation,
the residue is partitioned between water and dichloromethane, the
organic phase is dried over magnesium sulfate and evaporated. to
afford (6,7-dimethoxy-1-morpholin-4-yl-isoquinolin-4-yl)-acetic
acid ethyl ester [MH].sup.+ 361. The crude ester (0.240 g, 0.66
mmol) is dissolved in ethanol (20 ml), treated with 2M sodium
hydroxide (3 ml) and stirred at room temperature overnight. After
adjustment to pH 1 with concentrated hydrochloric acid, the solvent
is evaporated and the crude acid used directly for formation of the
xanthine derivative.
[0127] Intermediate 28
[0128] The procedure for Intermediate 27 is repeated, using excess
N-methylpiperazine in place of morpholine to afford
[6,7-dimethoxy-1-(4-methyl-piperazin-1-yl)-isoquinolin-4-yl]-acetic
acid ethyl ester (0.186 g, 38%) .sup.1H NMR (DMSO-d6) .delta. 1.19
(t J 7 3H), 2.30 (s 3H), 2.61 (m 4H), 3.10-3.30 (m 4H), 3.92 (s
6H), 3.97 (s 2H), 4.10 (q J 7 2H), 7.19 (s 1H), 7.37 (s 1H), 7.91
(s 1H). The ester (0.186 g, 0.50 mmol) is dissolved in ethanol (20
ml), treated with 2M sodium hydroxide (3 ml) and stirred at room
temperature overnight. After adjustment to pH 1 with concentrated
hydrochloric acid, the solvent is evaporated and the crude acid
used directly for formation of the xanthine derivative.
[0129] Intermediate 29
[0130] N-Chlorosuccinimide (0.347 g, 2.60 mmol) is added to a
solution of 6-methoxyisoquinoline (Synth. Commun. 1999, 29, 1617)
(0.207 g, 1.30 mmol) in acetic acid (9 ml). The reaction is heated
at 50.degree. C. for 3 hours, cooled to ambient temperature,
evaporated and partitioned between ethyl acetate and 1M aqueous
sodium hydroxide. The organic phase is washed with water and brine,
dried over magnesium sulfate and evaporated afford
5-chloro-6-methoxyisoquinoline, [MH].sup.+ 194. A solution of this
intermediate (0.175 g, 0.90 mmol) in THF (4.5 ml) and acetic
anhydride (0.101 ml, 1.08 mmol) is treated with sodium
triacetoxyborohydride (0.229 g, 1.08 mmol) and the reaction is
stirred at ambient temperature for 22 hours. The solvent is
evaporated, the residue is taken into ethyl acetate, washed with
0.5M aqueous hydrochloric acid, then brine and dried over magnesium
sulfate. Evaporation affords
1-(5-chloro-6-methoxy-1H-isoquinolin-2-yl)-ethanone, mp
78-80.degree. C. A suspension of this intermediate (0.150 g, 0.60
mmol) and glyoxylic acid. (76 mg, 0.80 mmol) in 6M aqueous
hydrochloric acid (2.8 ml) is heated at 100.degree. C. for 3 hours.
After cooling to ambient temperature, the resultant solid is
collected by filtration to afford
(5-chloro-6-methoxy-isoquinolin-4-yl)-acetic acid, [MH].sup.+ 252.
A suspension of this intermediate (0.970 g, 3.38 mmol) and ammonium
formate (1.05 g, 16.9 mmol) in 1:1 acetic acid-water (25 ml) is
treated with 10% Pd/C (0.730 g) and stirred at ambient temperature
for 16 hours. After filtration through Celite.RTM., the combined
filtrate and washings are evaporated and purified by Soxhlet
extraction with acetone to afford
(6-methoxy-isoquinolin-4-yl)-acetic acid [MH].sup.+ 218.
Alternatively reduction of
(5-chloro-6-methoxy-isoquinolin-4-yl)-acetic acid to afford
(6-methoxy-isoquinolin-4-yl)-acetic acid is accomplished by
stirring a suspension of
(5-chloro-6-methoxy-isoquinolin-4-yl)-acetic acid (20 g, 69.4 mmol)
in 1 Molar sodium hydroxide solution (400 mL) for 20 min, filtering
off the resultant salt and then treating with hydgrogen gas in the
presence of 10% Pd/C (1.4 g) at atmospheric pressure for 2.25 h.
The resulting suspension is filtered through glass wool and celite,
washing with water (50 mL). The solution is then cooled in an ice
water bath and slowly (30 min) neutralised and then acidified with
5 Molar hydrochloric acid (80 ml). A suspension forms and further
crystalisation is encouraged by standing at 5.degree. C. for 20 h.
The resulting crystals are removed by filtration and washed with
ice cold ethanol (25 ml) drying under reduced pressure gives
(6-methoxy-isoquinolin-4-yl)-acetic acid.
[0131] Intermediate 30
[0132] Glyoxylic acid (1.37 g, 9.28 mmol) is added to mixture of
1-(6-chloro-1H-isoquinolin-2-yl)-ethanone [J. Org. Chem., 1980, 45,
1950] (1.44 g, 5.90 mmol) in 6N HCl (24 ml). The reaction is heated
at 100.degree. C. for 3 hours, cooled to RT, washed with ether and
evaporated to 10 ml volume. After overnight refrigeration, the
solid is collected by filtration and dried to afford
(6-chloro-isoquinolin-4-yl)-acetic acid hydrochloride. .sup.1H NMR
(400 MHz, DMSO) .delta.: 4.45 (s 2H), 8.18 (d J 9 1H), 8.52 (s 1H),
8.70 (d J 8 1H), 8.83 (s1H), 9.96 (s 1H).
[0133] Intermediate 31
[0134] Sodium borohydride (1.12 g, 29.6 mmol) is added portionwise
to a cooled (0.degree. C.) solution of 6-bromoisoquinoline [J Chem
Soc Perkin Trans 2, 1998, 437] (1.544 g, 7.42 mmol) in acetic acid
(10 ml) and acetic anhydride (3 ml). After heating at 60.degree. C.
for 4 hours, the mixture is cooled, evaporated and diluted with
water. After adjustment to pH 10 with potassium carbonate and
extraction with ethyl acetate, the combined organic phrases are
washed twice with 0.5N HCl and brine, then dried over sodium
sulphate. Evaporation affords
1-(6-bromo-1H-isoquinolin-2-yl)-ethanone, MH.sup.+ 253. Glyoxylic
acid (0.812 g, 8.80 mmol) is added to mixture of
1-(6-bromo-1H-isoquinolin-2-yl)-ethanone (1.50 g, 5.90 mmol) in 6N
HCl (20 ml). The reaction is heated at 100.degree. C. for 2 hours,
cooled to RT and washed with ethyl acetate. After evaporation, the
residue is taken into methanol (20 ml), concentrated sulphuric acid
(10 drops) is added and the mixture heated at reflux for 14 hours.
After partial evaporation of the solvent, the resultant solid is
collected by filtration, washed with methanol and dried to afford
(6-bromo-isoquinolin-4-yl)-acetic acid methyl ester hydrochloride,
MH.sup.+ 281. Lithium hydroxide hydrate (8.5 mg, 0.20 mmol) is
added to a cooled (0.degree. C.) solution of
(6-bromo-isoquinolin-4-yl)-acetic acid methyl ester (50 mg, 0.18
mmol) in 3:1 THF-water (3 ml). After 1 hour the solvent is
evaporated to afford (6-bromo-isoquinolin-4-yl)-acetic acid lithium
salt, MH.sup.+ 266.
[0135] Intermediate 32
[0136] Trimethylsilylacetylene (0.17 ml, 1.23 mmol) is added to a
suspension of (6-bromo-isoquinolin-4-yl)-acetic acid methyl ester
(0.325 g, 1.03 mmol) in DMF (1.75 ml) and triethylamine (10 ml),
follwed by copper(I) iodide (40 mg, 0.20 mmol) and
(Ph.sub.3P).sub.2PdCl.sub.2 (73 mg, 0.10 mmol). The reaction is
heated at 45.degree. C. for 40 minutes, cooled to ambient
temperature and diluted with ethyl acetate. After washing with
water and brine, the organic phase is dried over magnesium sulfate,
evaporated and purified by flash column chromatography (1:1 ethyl
acetate-hexane elution) to afford
(6-trimethylsilanylethynyl-isoquinolin-4-yl)-acetic acid methyl
ester, [MH].sup.+ 298. This intermediate (0.221 g, 0.74 mmol) is
dissolved in methanol (7.5 ml) and treated with potassium carbonate
(75 mg, 0.54 mmol). The reaction is stirred for 30 minutes at
ambient temperature, evaporated and purified by flash
chromatography (5:1 dichloromethane-methanol elution) to afford
(6-ethynyl-isoquinolin-4-yl)-acetic acid, [MH].sup.+ 212.
[0137] Intermediate 33
[0138] Bromine (0.211 ml, 6.28 mmol) in dichloromethane (10 ml) is
added to a cooled (0.degree. C.) solution of 6-methoxyisoquinoline
[Synth. Commun. 1999, 29, 1617] and the reaction is stirred at
ambient temperature for 20 hours. After pouring into 1M aqueous
sodium hydroxide, the organic phase is washed with brine, dried
over magnesium sulfate and evaporated. The crude product is
purified by flash column chromatography (20:1
dichloromethane-methanol elution) to afford
5-bromo-6-methoxyisoquinoline, [MH].sup.+ 240. This material is
then converted according to the procedure for Intermediate 29 into
(5-bromo-6-methoxy-isoquinolin-4-yl)-acetic acid [MH].sup.+
298.
[0139] Intermediate 34
[0140]
[1-(3,5-Diisopropoxy-phenyl)-6,7-dimethoxy-isoquinolin-4-yl]-aceti-
c acid is prepared using the general procedure for Intermediate 20,
.sup.1H NMR (400 MHz CDCl.sub.3) .delta. 1.25 (d J 6 12H), 3.78 (s
3H), 3.86 (s 2H), 3.92 (s 3H), 6.46 (d J 0.5 1H), 6.65 (d J 0.5
2H), 7.20 (s 2H), 8.30 (s 1H).
[0141] The following are prepared analogously to Intermediate
21:
[0142] Intermediate 35:
1-(3,5-Dimethoxy-phenyl)-6-isopropoxy-7-methoxy-isoquinolin-4-yl]-acetic
acid, [MH].sup.+ 412.
[0143] Intermediate 36:
(1-.tert.-Butyl-6-isopropoxy-7-methoxy-isoquinolin-4-yl)-acetic
acid, .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 1.32 (d J 7 6H),
1.52 (s 9H), 3.80 (s 2H), 3.90 (s 3H), 4.75 (heptet J 7 1H), 7.28
(s 1H), 7.66 (s 1H), 8.08 (s 1H).
[0144] Intermediate 37:
(6-Isopropoxy-1-isopropyl-7-methoxy-isoquinolin-4-yl)-acetic acid,
[MH].sup.+ 318.
[0145] The following are prepared analogously to Intermediate
20:
[0146] Intermediate 38:
(6,7-Dimethoxy-1-methyl-isoquinolin-4-yl)-acetic acid, [MH].sup.+
262.
[0147] Intermediate 39:
(1-tert.-Butyl-6,7-dimethoxy-isoquinolin-4-yl)-acetic acid, .sup.1H
NMR (400 MHz, CDCl.sub.3) d 1.75 (s 9H), 3.95 (s 6H), 4.04 (s 2H),
7.28 (s 1H), 7.75 (s 1H), 8.66 (s 1H).
[0148] Intermediate 40:
(1-Isopropyl-6,7-dimethoxy-isoquinolin-4-yl)-acetic acid,
characterised as the ethyl ester .sup.1H NMR (400 MHz, CDCl.sub.3)
.delta. 1.25 (t J 7 3H), 1.45 (d J 7 3H), 3.82 (heptet J 7 1H),
3.90 (s 2H), 3.08 (s 2H), 4.15 (q J 7 2H), 7.28 (s 1H), 7.48 (s
1H), 8.30 (s 1H).
[0149] Intermediate 41:
2-(7-Methoxy-1-morpholin-4-yl-isoquinolin-4-yl)-propionic acid mp
225-227.degree. C., is prepared according to the procedure for
Intermediate 27.
[0150] The following are prepared analogously to Intermediate
22:
[0151] Intermediate 42: [MH] 332
(7-Hydroxy-6-methoxy-isoquinolin-4-yl)-acetic acid lithium salt,
via (3-benzyloxy-4 -methoxy-benzyl)-(2,2-dimethoxy-ethyl
)-amine.
[0152] Intermediate 43:
(6,7-Dimethoxy-3-methyl-isoquinolin-4-yl)-acetic acid, .sup.1H NMR
(400 MHz, DMSO) .delta.: 2.50 (s 3H), 3.91 (s 3H), 3.93 (s 3H),
4.02 (s 2H), 7.30 (s 1H), 7.43 (s 1H), 8.30 (s 1H).
[0153] Intermediate 44:
(6-Ethoxy-7-methoxy-isoquinolin-4-yl)-acetic acid, 3 M.sup.+
261.
[0154] The following are prepared analogously to Intermediate 22,
using pyruvic acid in place of glyoxylic acid:
[0155] Intermediate 45:
2-(6-Ethoxy-7-methoxy-isoquinolin-4-yl)-propionic acid lithium
salt, characterised as the methyl ester, M.sup.+ 290.
[0156] Intermediate 46:
2-(7-Ethoxy-6-methoxy-isoquinolin-4-yl)-propionic acid lithium
salt, characterised as the methyl ester, M.sup.+ 290.
[0157] Intermediate 47:
2-(6,7-dimethoxy-isoquinolin-4-yl)-propionic acid, characterised as
the methyl ester, M.sup.+ 276.
[0158] Intermediate 48: 8-Fluoro-6-methoxy-isoquinolin-4-yl)-acetic
acid, is prepared according to the procedure for Intermediate 31
and characterised as the methyl ester, [MH].sup.+ 250.
[0159] Intermediate 49: (6,7-dimethoxy-isoquinolin-4-yl)-acetic
acid, and Intermediate 50,
[1,3]dioxolo[4,5-.g.]isoquinolin-8-yl-acetic acid, are prepared as
described in Dyke et al, Tetrahedron 1968, 24, 1467.
[0160] Intermediate 51: (7-methoxy-isoquinolin-4-yl)-acetic acid is
prepared according to Dyke et al, Tetrahedron, 1973, 29, 3881.
[0161] Intermediate 52: 2,2-Dimethoxyethylamine (13.85 ml, 0.13
mol) is added to a solution of 3-fluoro-4-methoxybenzaldehyde (20
g, 0.13 mol) in toluene (200 ml). The resulting solution is flushed
with nitrogen gas and then heated overnight under reflux in a
Dean-Stark apparatus. The solvent is then removed under reduced
pressure to yield
(2,2-dimethoxy-ethyl)-[1-(3-fluoro-4-methoxy-phenyl)-methylidene]-amine.
This intermediate (31 g, 0.13 mol) is dissolved in ethylacetate and
acetic anhydride (13.1 g, 0.13 mol) added. Platinum oxide,(0.3 g)
is then added, under a blanket of nitrogen, and the resulting
mixture is stirred under a hydrogen atmosphere until uptake is
complete. Filtration, washing with saturated aqueous NaHCO.sub.3
(3.times.100 ml), brine and water, drying over MgSO.sub.4 and
concentration then gives
N-(2,2-dimethoxy-ethyl)-N-(3-fluoro4-methoxy-benzyl)-acetamide.
This intermediate (38.9 g, ca 0.13 mol) is dissolved in anhydrous
CH.sub.2Cl.sub.2 and then added slowly over 20mins to a stirred
mixture of A1C1.sub.3 (90 g) and CH.sub.2Cl.sub.2 under an
atmosphere of nitrogen. The total volume of CH.sub.2Cl.sub.2 is 250
ml. The mixture is stirred for a further 10 mins at room
temperature and is then cooled with an ice bath during the addition
of aqueous 40% NaOH. The mixture is further diluted with water (250
ml), filtered through glass wool, the organic phase separated and
the aqueous phase further extracted with CH.sub.2Cl.sub.2
(2.times.200 ml). Drying over MgSO.sub.4 and evaporation under
reduced pressure yields a crude oil which is purified by flash
silica chromatography (eluant: 1% methanol in CH.sub.2Cl.sub.2) to
give as one of the products
1-(7-fluoro-6-methoxy-1H-isoquinolin-2-yl)-ethanone. This
intermediate (0.60 g, 2.7 mmol) is mixed with glyoxylic acid (0.325
g, 3.5 mmol) and water (10 ml) and the resulting mixture is stirred
at room temperature for 20 min. Concentrated hydrochloric acid (10
ml) is then added and the mixture heated to reflux for 1 h.
Concentration and purification by preparative HPLC gives
(7-fluoro-6-methoxy-isoquinolin-4-yll)-acetic acid, [MH].sup.+
236.
[0162] The following are prepared analogously to Intermediate
20:
[0163] Intermediate 53:
(1-Methyl-6-methoxy-isoquinolin-4-yl)-acetic acid.
[0164] Intermediate 54:
(6-Isopropoxy-1-methyl-isoquinolin-4-yl)-acetic acid.
[0165] Intermediate 55: (6-Ethoxy-1-methyl-isoquinolin-4-yl)-acetic
acid.
[0166] Intermediate 56: A solution of
(6-bromo-isoquinolin-4-yl)-acetic acid methyl ester (52 mg, 0.19
mmol), prepared as described as an intermediate for Intermediate
31, in DMF (3 ml) is added to zinc dicyanide (26 mg, 0.22 mmol)
under a nitrogen atmosphere. To the resulting mixture is added
1,1'-bis(diphenylphosphino)ferrocene (15 mg) and
tris(dibenzylideneacetone)dipalladium(0) (8 mg) and the resulting
mixture stirred at 120.degree. C. for 22 h. The solution is cooled
and diluted with chloroform (30 ml) and washed with water
(2.times.20 ml) followed by brine (20 ml). Further chlorofrom is
added (40 ml) and the solution dried over MgSO.sub.4, filtered and
concentrated. Repetitive flash silica column chromatography
(eluants 40:1 CH.sub.2Cl.sub.2:methanol, then 50:1
CH.sub.2Cl.sub.2:methanol) gives (6-cyano-isoquinolin-4-yl)-acetic
acid methyl ester [MH].sup.+ 227. This intermediate is saponified
by treatment with LiOH in 3:1 THF/water. The resulting mixture is
partially evaporated to remove the THF, diluted to 10 ml with water
then washed with ethyl acetate. The aqeous phase is then
neutralised with 1M hydrochloric acid (to pH 4-5) and exhaustively
extracted with ethylacetate. The organic phase is dried over
MgSO.sub.4, filtered and concentrated to give
(6-cyano-isoquinolin-4-yl)-acetic acid M.sup.+ 212.
[0167] Intermediate 57:
(5-Chloro-6-methoxy-isoquinolin-4-yl)-acetic acid is prepared as
described in the procedure for intermediate 29.
[0168] Intermediate 58: To a solution of
(6-trimethylsilanylethynyl-isoquinolin-4-yl)-acetic acid methyl
ester, as prepared for Intermediate 32 (0.19 g, 0.64 mmol), in
anhydrous methanol (7 ml) is added K.sub.2CO.sub.3 (72 mg) and the
resulting mixture stirred for 1 h. Additional K.sub.2CO.sub.3 (11
mg) is then added and stirring continued for 30 min. The mixture is
then neutralised with glacial acetic acid and concentrated.
Purification by flash silica column chromatography
(ethylacetate/hexane 1:1) gives (6-ethynyl-isoquinolin4-yl)-acetic
acid methyl ester M.sup.+ 225. This intermediate (79 mg, 0.35 mmol)
is dissolved in methanol under an inert atmosphere and 10% Pd on
carbon (79 mg) added. The resulting suspension is stirred
vigorously under an atmosphere of gaseous hydrogen. After 90 mins,
filtration, washing with methanol and concentration give
(6-ethyl-isoquinolin-4-yl)-acetic acid methyl ester M.sup.+ 229. To
a solution of this intermediate (68 mg, 0.30 mmol) in
THF/methanol/water (3:1:1, 3.5 ml) is added LiOH (12.5 mg) and the
mixture stirred for 20 h at room temperature. Concentration under
reduced pressure gives lithium (6-ethyl-isoquinolin-4-yl)-acetate
M.sup.+ 221.
[0169] Intermediate 59: A solution of Intermediate 29 (0.5 g, 2.3
mmol) is suspended in aqueous 48% HBr (10 ml) and then heated at
100.degree. C. for 48 h. Further aqueous 48% HBr (10 ml) is then
added and heating continued at 100.degree. C. for an additional 24
h. The reaction mixture is cooled to 5.degree. C. for 4 h and the
resulting solid seperated by filtration. Washing with water and
drying under high vacumn at 50.degree. C. gives
(6-hydroxy-isoquinolin-4-yl)-acetic acid hydrobromide [MH].sup.+
204.4. This intermediate (0.15 g, 0.53 mmol) is suspended in DMF (2
ml) and K.sub.2CO.sub.3 (0.22 g, 1.58 mmol) added followed by
ethyliodide (0.085 ml, 1.06 mmol) and the resulting mixture stirred
at room temperature for 2 h. Concentration and purification by
flash silica column chromatography (eluant: CH.sub.2Cl2/methanol
10:1) gives (6-ethoxy-isoquinolin-4-yl)-acetic acid ethyl ester
[MH].sup.+ 260. This intermediate (25 mg, 0.11 mmol) is dissolved
in water (1 ml) and LiOH added (5 mg, 0.11 mmol). The resulting
mixture is stirred for 30 min at room temperature. Acidification
with minimumn 6N HCl and concentration gives crude
(6-ethoxy-isoquinolin-4-yl)-acetic acid.
EXAMPLES 1-70
[0170] Compounds of formula I which are also of formula
##STR28##
[0171] where R.sup.1 to R.sup.4 and R.sup.8 to R.sup.13 are as
hereinbefore defined, in free or salt form, and their methods of
preparation are shown in the following table, the methods being
described hereinafter. R.sup.3 is H in all Examples except No 44,
where it is CH.sub.3. R.sup.4 is H in all examples except Nos 25-27
and 41-43, where it is CH.sub.3. R.sup.9 is H in all Examples
except No 29, where it is CH.sub.3. R.sup.10 is H in all Examples
except No 57, where it is Br and No 75 where it is Cl. R.sup.13 is
H in all Examples except Nos 56 where it is F, and 65 and 66, where
it is Br. TABLE-US-00002 React- ing Inter- Ex. m/z me- No. R.sup.1
R.sup.2 R.sup.8 R.sup.11 R.sup.12 MH+ MH- Method diates 1 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 ##STR29## OCH.sub.3 OCH.sub.3 560 A 11 +
20 2 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 ##STR30## OCH.sub.3
OCH.sub.3 616 A 11 + 34 3 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2
##STR31## OCH(CH.sub.3).sub.2 OCH.sub.3 644 A 11 + 21 4 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 ##STR32## OCH(CH.sub.3).sub.2 OCH.sub.3
588 A 11 + 35 5 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2
(CH.sub.3).sub.3C OCH(CH.sub.3).sub.2 OCH.sub.3 508 A 11 + 36 6
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 (CH.sub.3).sub.2CH
OCH(CH.sub.3).sub.2 OCH.sub.3 494 A 11 + 37 7 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 CH.sub.3 OCH.sub.3 OCH.sub.3 437 A 11 +
38 (M+) 8 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 (CH.sub.3).sub.3C
OCH.sub.3 OCH.sub.3 480 A 11 + 39 9 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 (CH.sub.3).sub.2CH OCH.sub.3 OCH.sub.3
465 A 11 + 40 (M+) 10 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H
OCH.sub.3 OCH.sub.3 424 C 11 + 49 11 CH.sub.3 ##STR33## H OCH.sub.3
OCH.sub.3 513 A 2 + 49 12 H CH.sub.3 H OCH.sub.3 OCH.sub.3 C 12 +
49 13 CH.sub.3 CH.sub.2.dbd.CHCH.sub.2 H OCH.sub.3 OCH.sub.3 C 13 +
49 14 CH.sub.3 ##STR34## H OCH.sub.3 OCH.sub.3 C 14 + 49 15
CH.sub.3 (CH.sub.3).sub.3CCH.sub.2 H OCH.sub.3 OCH.sub.3 C 15 + 49
16 (CH.sub.3).sub.2CHCH.sub.2 (CH.sub.3).sub.2CHCH.sub.2 H
OCH.sub.3 OCH.sub.3 C 16 + 49 17 CH.sub.3 ##STR35## H OCH.sub.3
OCH.sub.3 C 17 + 49 18 CH.sub.3 CH.sub.2.dbd.C(CH.sub.3)CH.sub.2 H
OCH.sub.3 OCH.sub.3 C 1 + 49 19 CH.sub.3 ##STR36## H OCH.sub.3
OCH.sub.3 C 5 + 49 20 CH.sub.3 ##STR37## H OCH.sub.3 OCH.sub.3 C 6
+ 49 21 H CH.sub.3CH.sub.2CH.sub.2 H OCH.sub.3 OCH.sub.3 C 18 + 49
22 CH.sub.3 ##STR38## H OCH.sub.3 OCH.sub.3 515 C 3 + 49 23
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H ##STR39## C 11 + 50 24
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H H OCH.sub.3 394 C 11 + 51 25
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 Cl H OCH.sub.3 442 C 11 + 24 26
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 CN H OCH.sub.3 433 C 11 + 25 27
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 ##STR40## H OCH.sub.3 493 C 11
+ 41 28 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 OH 410.7 D
11 + 42 29 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3
OCH.sub.3 438.6 D 11 + 43 30 CH.sub.3 CH.sub.3(CH.sub.2).sub.5 H
OCH.sub.3 OCH.sub.3 452.8 D 7 + 49 31 CH.sub.3 ##STR41## H
OCH.sub.3 OCH.sub.3 518.4 D 8 + 49 32 CH.sub.3 ##STR42## H
OCH.sub.3 OCH.sub.3 502.4 D 9 + 49 33 CH.sub.3 ##STR43## H
OCH.sub.3 OCH.sub.3 527.8 D 10 + 49 34 CH.sub.3 ##STR44## H
OCH.sub.3 OCH.sub.3 487.9 D 19 + 49 35 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 Cl OCH.sub.3 OCH.sub.3 458.4 D 11 + 23
36 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H H H 364 C 11 + 26 37
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.2CH.sub.3 OCH.sub.3
438 C 11 + 44 38 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 ##STR45##
OCH.sub.3 OCH.sub.3 509.1 D 11 + 27 39 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 ##STR46## OCH.sub.3 OCH.sub.3 522.02 D
11 + 28 40 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3
OCH.sub.2CH.sub.3 438 C 11 + 22 41 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.2CH.sub.3 OCH.sub.3 452 C 11 +
45 42 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3
OCH.sub.2CH.sub.3 452 C 11 + 46 43 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 OCH.sub.3 438 C 11 + 47 44
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 OCH.sub.3 438 J --
45 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 H 394 B2 11 + 29
46 CH.sub.3 ##STR47## H OCH.sub.3 H 408 C 6 + 29 47 CH.sub.3
(CH.sub.3).sub.3CCH.sub.2 H Cl H 410 C 15 + 30 48 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 H Cl H 396 C 11 + 30 49 CH.sub.3
##STR48## H OCH.sub.3 H C 14 + 29 50 CH.sub.3 ##STR49## H Cl H 394
C 14 + 30 51 CH.sub.3 ##STR50## H OCH.sub.3 OCH.sub.3 436.6 434.5
B1 4 + 49 52 CH.sub.3 CH.sub.2.dbd.C(CH.sub.3)CH.sub.2 H OCH.sub.3
H 392 390 C 1 + 29 53 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H Br H
441 C 11 + 31 54 CH.sub.3 (CH.sub.3).sub.3CCH.sub.2 H OCH.sub.3 H
408 C 15 + 29 55 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H C.ident.CH H
388 B1 11 + 32 56 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 H
412 C 11 + 48 57 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 H
473 C 11 + 33 58 CH.sub.3 ##STR51## H OCH.sub.3 OCH.sub.3 E -- 59
CH.sub.3 ##STR52## H OCH.sub.3 OCH.sub.3 F -- 60 CH.sub.3 ##STR53##
H OCH.sub.3 OCH.sub.3 580 F -- 61 CH.sub.3 ##STR54## H OCH.sub.3
OCH.sub.3 578 (M+) F -- 62 CH.sub.3 ##STR55## H OCH.sub.3 OCH.sub.3
473 E -- 63 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H H OH 379 G -- 64
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OH OH 396 G -- 65 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 H OH OH 474 H -- 66 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 H H OH H -- 67 CH.sub.3
HO(CH.sub.2).sub.3 H OCH.sub.3 OCH.sub.3 426 I -- 68 CH.sub.3
##STR56## H OCH.sub.3 OCH.sub.3 440 I -- 69 CH.sub.3 ##STR57## H
OCH.sub.3 OCH.sub.3 482 K -- 70 CH.sub.3 ##STR58## H OCH.sub.3
OCH.sub.3 436 L -- 71 CH.sub.3 ##STR59## H OCH.sub.3 H 434 B1 17 +
29 72 CH.sub.3 ##STR60## H OCH.sub.3 H 422 B1 5 + 29 73 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 F 412 410 B1 11 + 52 74
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H CO.sub.2H H 408 C 11 + 56 75
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.3 H 428 B1 11 + 57 76
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H CN H 389 M 77 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 H CH.sub.2CH.sub.3 H 392 B1 11 + 58 78
CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 H OCH.sub.2CH.sub.3 H 408.54 B1
11 + 59 79 CH.sub.3 ##STR61## H OCH.sub.3 H 443.44 B1 + E 3 + 29 80
CH.sub.3 ##STR62## H OCH.sub.3 H 549 547 F 81 CH.sub.3 ##STR63## H
OCH.sub.3 H 549 M.sup.+ F 82 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2
N(CH.sub.2).sub.3 OCH.sub.3 OCH.sub.3 467 465 N 11 + 23 83 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 ##STR64## OCH.sub.3 OCH.sub.3 507 505 O
11 + 23 83 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 CH.sub.3 OCH.sub.3 H
408 406 A 11 + 53 84 CH.sub.3 (CH.sub.3).sub.2CHCH.sub.2 CH.sub.3
OCH(CH.sub.3).sub.2 H M.sup.+ A 11 + 54 435 85 CH.sub.3
(CH.sub.3).sub.2CHCH.sub.2 CH.sub.3 OCH.sub.2CH.sub.3 H 422 420 A
11 + 55
[0172] Method A
[0173] 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
(0.201 g, 1.30 mmol) is added to
5,6-diamino-1-isobutyl-3-methyl-1H-pyrimidine-2,4-dione (0.223 g,
1.05 mmol)) and (6,7-dimethoxy-1-methyl-isoquinolin-4-yl)-acetic
acid (0.25 g, 0.96 mmol) in methanol (5 ml) and water (1 ml) and
the mixture is stirred at ambient temperature for 16 hours. The
methanol is evaporated and the resultant solid collected by
filtration, taken into methanol. (5 ml) and 5M aqueous sodium
hydroxide (0.5 ml) is added. The reaction is heated to reflux for 1
hour, cooled to ambient temperature and evaporated. The residue is
dissolved in water and extracted with dichloromethane, the combined
organic extracts are dried over sodium sulfate and evaporated to
afford
8-(6,7-dimethoxy-1-methyl-isoquinolin-4-ylmethyl)-3-isobutyl-1-met-
hyl-3,7-dihydro-purine-2,6-dione, M.sup.+ 437.
[0174] Method B1
[0175] (6-Ethynyl-isoquinolin-4-yl)-acetic acid (58 mg, 0.28 mmol)
is dissolved in DMF (1 ml) and
O-(7-azabenzotriazo-1-yl)-N,N,N',N'-tetramethyluronium
hexafluorophosphate (0.125 g, 0.33 mmol) and Hunig's base (0.180
ml, 1.03 mmol) are added, followed by a solution of
5,6-diamino-1-isobutyl-3-methyl-1H-pyrimidine-2,4-dione (58 mg,
0.28 mmol) in DMF (0.7 ml). The reaction is stirred at room
temperature for 2 hours. The solvent is evaporated and the residue
purified by flash column chromatography (30:1
dichloromethane-methanol elution). The intermediate is dissolved in
methanol (2 ml) and water (2.75 ml) added, followed by 4M aqueous
sodium hydroxide (0.25 ml). The reaction is heated at 40.degree. C.
for 2 hours, then stirrred for 16 hours at ambient temperature. The
solvent is evaporated and the crude product purified by flash
column chromatography (30:1 dichloromethane-methanol elution) to
afford
8-(6-ethynyl-isoquinolin-4-ylmethyl)-3-isobutyl-1-methyl-3,7-dihydro-puri-
ne-2,6-dione, [MH].sup.+ 388.
[0176] Method B2
[0177] A suspension of (6-methoxy-isoquinolin-4-yl)-acetic acid
(3.5 g, 13.82 mmol) in acetonitrile (70 ml) is treated sequentially
with Hunig's base (6.15 ml, 36 mmol),
O-(7-benzotriazo-1-yl)-N,N,N',N'-tetramethyluronium
hexafluorophosphate (6.29 g, 16.6 mmol) and
5,6-diamino-1-isobutyl-3-methyl-1H-pyrimidine-2,4-dione (3.22 g,
15.2 at mmol) while the solution is stirred at room temperature.
The reaction is stirred at ambient temperature for 2 h, prior to
evaporation of the solvent. The residue is tritruated with ethyl
acetate (50 ml) filtered and washed with ethyl acetate and then
dried at 50.degree. C. under reduced pressure. The resulting
intermediate is suspended in a mixture of methanol (30 ml) and 4M
aqueous sodium hydroxide (60 ml) and heated at 80.degree. C. for 45
minutes. This suspension is neutralised with acetic acid and cooled
to 0-5.degree. C. overnight. The resultant solid is collected by
filtration, and washed with methanol/water 1:9 (30 ml) followed by
methanol (30 ml). Drying under high vacuum at 50.degree. C. affords
3-isobutyl-8-(6-methoxy-isoquinolin-4-ylmethyl)-1-methyl-3,7-dihy-
dro-purine-2,6-dione, [MH].sup.+ 394.5.
[0178] Method C
[0179] 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
(5.6M aqueous solution, 0.33 ml, 1.85 mmol) is added to a
suspension of
5,6-diamino-1-isobutyl-3-methyl-1H-pyrimidine-2,4-dione (0.327 g,
1.54 mmol), (1-chloro-6,7-dimethoxy-isoquinolin-4-yl)-acetic acid
(0.414 g, 1.54 mmol) and 1-hydroxybenzotriazole (0.251 g, 1.85
mmol) in CH.sub.2Cl.sub.2 (2 ml). Water (2 ml) is added, the
biphasic mixture is shaken for 18 hours and the the resultant solid
is collected by filtration. This intermediate is suspended in
methanol (10 ml), 4M aqueous NaOH (5 ml) is added and the mixture
heated to reflux for 4 hours. After evaporation of the methanol,
the residue is acidified to pH2 with concentrated hydrochloric acid
and the resultant solid collected by filtration and purified by
preparative HPLC to afford
8-(1-chloro-6,7-dimethoxy-isoquinolin-4-ylmethyl)-3-isobutyl-1-methyl-3,7-
-dihydro-purine-2,6-dione hydrochloride, [MH].sup.+ 458.
[0180] Method D
[0181] 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide (20.6 ml, 0.11
mol) is added to a mixture of
5,6-diamino-1-isobutyl-3-methyl-1H-pyrimidine-2,4-dione (20 g,
0.094 mol), (5,6-dimethoxy-isoquinolin-4-yl)-acetic acid (26.7 g,
0.094 mol), and 1-hydroxybenzotriazole (19.2 g, 0.142 mol) in 1:1
dichloromethane-water (400 ml). The reaction is stirred at ambient
temperature for 4.5 hours and the resultant solid collected by
filtration. Slurrying in water (500 ml), filtration and washing
with water (250 ml) followed by drying, further tritruation with
methanol and drying gives an intermediate together with slightly
less pure material from concentration of the methanol triturate.
The intermediate (16.08 g) is dissolved in water (100 ml) and
methanol (100 ml) followed by the addition of 4M aqueous sodium
hydroxide (56 ml) and the resultant solution is heated at
70.degree. C. over night. After cooling to ambient temperature, the
methanol is evaporated and the residue acidified to pH 1 with
concentrated hydrochloric acid. The resultant hydrochloride salt is
collected by filtration and dried. The product is then be converted
to the free base by treatment with aqueous sodium hydroxide to pH
11 and washing with water to afford
3-isobutyl-8-(5,6-dimethoxy-isoquinolin-4-ylmethyl)-1-methyl-3,7-dihydro--
purine-2,6-dione [MH].sup.+ 424.6.
[0182] Method E
[0183] A suspension of the product of Example 11 (72 mg, 0.13 mmol)
in 6N HCl (2.5 ml) and ethanol (1.5 ml) is heated to reflux for 5
hours then stood at room temperature overnight. The resultant
precipitate is collected by filtration, washed with water and dried
to afford
3-(3-amino-benzyl)-8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-1-methyl-3,7--
dihydro-purine-2,6-dione dihydrochloride, .sup.1H NMR (400 MHz,
DMSO) .delta.: 3.20 (s 3H), 3.95 (s 3H), 4.00 (s 3H), 4.75 (s 2H),
5.15 (s 2H), 7.15 (m 2H), 7.20 (s 1H), 7.30 (t J 6 1H), 7.65 (s,
1H), 7.95 (s 1H), 8.50 (s 1H), 9.50 (s 1H), 13.6 (br s 1H).
[0184] Method F
[0185] The product of Example 58 (37 mg, 0.07 mmol) is suspended in
pyridine (1.5 ml) and dimethylsulfamoyl chloride (23 ml, 0.21 mmol)
is added. The reaction is heated at 50.degree. C. for 22 hours and
the solvent is evaporated. Trituration with water gives a solid
which is collected by filtration and dried to afford
3-[3-(N,N-dimethylsulfamoyl)amino-benzyl]-8-(6,7-dimethoxy-isoquinolin-4--
ylmethyl)-1-methyl-3,7-dihydro-purine-2,6-dione, .sup.1H NMR (400
MHz, DMSO) .delta.: 2.64 (s 6H), 3.26 (s 3H), 3.86 (s 3H), 3.98 (s
3H), 4.50 (s 2H), 5.15 (s 2H), 6.98 (d J 6 1H), 7.08 (d J 6 1H),
7.15 (s 1H), 7.22 (t J 6 3H), 7.55 (s 1H), 7.62 (s 1H), 8.38 (s
1H), 9.15 (s 1H), 9.82 (s 1H), 13.60 (s 1H).
[0186] Method G
[0187] The product of Example 24 (100 mg, 0.25 mmol) is heated at
100.degree. C. in concentrated hydrobromic acid (5 ml) for 36
hours. The solvent is evaporated and the crude product purified by
preparative HPLC to afford
8-(7-hydroxy-isoquinolin-4-ylmethyl)-3-isobutyl-1-methyl-3,7-di-
hydro-purine-2,6-dione, [M].sup.+ 379.
[0188] Method H
[0189] The product of Example 64 (41 mg, 0.09 mmol) is dissolved in
acetic acid (2 ml) and treated with bromine in acetic acid (148
mg/ml solution: 100 .mu.l). After 1 hour at room temperature the
solvent is evaporated, the residue dissolved in hot methanol,
filtered and evaporated to afford
8-(8-bromo-6,7-dihydroxy-isoquinolin-4-ylmethyl)-3isobutyl-1-methyl-3,7-d-
ihydro-purine-2,6-dione, M.sup.+ 474.
[0190] Method I
[0191] A suspension of the product of Example 13,
3-allyl-8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-1-methyl-3,7-dihydro-pur-
ine-2,6-dione hydrochloride salt (0.760 g, 1.87 mmol),
9-borabicyclo[2.2.0]nonane (0.5M THF solution, 18.7 ml, 9.35 mmol)
and diisopropylethylamine (0.33 ml, 1.89 mmol) in THF (9 ml) is
heated to reflux for 2.5 hours. Sodium hydroxide (4M aqueous
solution, 6 ml) and hydrogen peroxide (27.5%, 3 ml) are added
sequentially and the reaction heated at 50.degree. C. for 1.5
hours. After evaporation, the crude product is purified by flash
chromatography (19:1 CH.sub.2Cl.sub.2:-methanol elution) and
triturated with water to afford
8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-3-(3-hydroxy-propyl)-1-methyl-3,-
7-dihydro-purine-2,6-dione, [MH].sup.+ 426.
[0192] Method J
[0193] Potassium carbonate (48 mg, 0.35 mmol) and iodomethane
(0.018 ml, 0.295 mmol) are added to a solution of the product of
Example 10,
8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-3-isobutyl-1-methyl-3,7-dihydro--
purine-2,6-dione (0.100 g, 0.24 mmol) in DMF (2 ml). The reaction
is stirred overnight and purified by preparative HPLC to afford
8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-3-isobutyl-1,7-dimethyl-3,7-dihy-
dro-purine-2,6-dione, [MH].sup.+ 438.
[0194] Method K
[0195] A suspension of the product of Example 68,
8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-3-(3-hydroxy-2-methyl-propyl)-1--
methyl-3,7-dihydro-purine-2,6-dione (63 mg, 0.14 mmol) and acetyl
chloride (18 ml, 0.25 mmol) in pyridine (1 ml) is heated at
50.degree. C. for 18 hours. After evaporation, flash chromatography
(19:1 dichloromethane-methanol elution) affords acetic acid
3-[8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-1-methyl-2,6-dioxo-1,2,6,7-te-
trahydro-purin-3-yl]-2-methyl-propyl ester, [MH].sup.+ 482.
[0196] Method L
[0197] The product of Example 18,
8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-1-methyl-3-(2-methyl-allyl)-3,7--
dihydro-purine-2,6-dione (100 mg, 0.24 mmol) is suspended in
1,2-dichloroethane (30 ml). Diethyl zinc (1M hexane solution, 1.2
ml, 1.20 mmol) is added, followed by chloroiodomethane (0.174 ml,
0.24 mmol) and the reaction is stirred at ambient temperature for 1
hour, prior to quenching with saturated aqueous NH.sub.4Cl. After
extraction with chloroform, the organic phase is washed with water,
dried over MgSO.sub.4 and evaporated. Purification by preparative
HPLC affords
8-(6,7-dimethoxy-isoquinolin-4-ylmethyl)-1-methyl-3-(1-methyl-cyclopropyl-
methyl)-3,9-dihydro-purine-2,6-dione, [MH].sup.+ 436.
[0198] Method M
[0199] The product of Example 53,
8-(6-bromo-isoquinolin-4-ylmethyl)-3-isobutyl-1-methyl-3,7-dihydro-purine-
-2,6-dione (245 mg, 0.554 mmol) is dispersed in a mixture of
triethylamine (0.085 ml, 0.61 mmol) and CH.sub.2Cl.sub.2 (4 ml). To
the stirred mixture is added dropwise a solution of di-tert
butoxycarbonate (133 mg, 0.61 mmol) in CH.sub.2Cl.sub.2 (1 ml);
after 2 h triethylamine (0.170 ml, 1.2 mmol), di-tert
butoxycarbonate (130 mg, 0.60 mmol) and DMF (0.3 ml) are added and
the mixture is stirred at room temperature for 2.5 days.
Concentration, partitioning between water and hexane, sonication
filtration, re-concentration followed by purification by flash
silica column chromatography (eluant 19:1 CH.sub.2Cl.sub.2:
methanol) gives
8-(6-bromo-isoquinolin-4-ylmethyl)-3-isobutyl-1-methyl-2,6-dioxo-1,2,3,6--
tetrahydro-purine-7-carboxylic acid .tert.-butyl ester ([MH].sup.+
543). This intermediate (58 mg, 0.11 mmol) is added to Zn(CN).sub.2
(15 mg, 0.13 mmol) followed by 1,1'-bis(diphenylphosphino)ferrocene
(9 mg), tris(dibenzylideneacetone)dipalladium(0) (5 mg) and
anhydrous DMF (2.5 ml) and the resulting mixture stirred at
120.degree. C. for 18 h and then for a further 24 h at 150.degree.
C. Zn(CN).sub.2 (57 mg, 0.49 mmol) and anhydrous DMF (1 ml) are
then added and the mixture is heated for 2 h at 155.degree. C. for
2 h followed by 18 h at 145.degree. C.
1,1'-Bis(diphenylphosphino)ferrocene (9 mg),
tris(dibenzylideneacetone)dipalladium(0) (9 mg) are then added and
the reaction is heated for a further 6 h at 145.degree. C.
Concentration, tritruation with water, filtration, washing with 1:1
saturated NaHCO.sub.3/water, followed by extraction with
CH.sub.2Cl.sub.2 and 1:1 methanol: CH.sub.2Cl.sub.2 and repetitive
flash silica column chromatography (eluants 10:1
CH.sub.2Cl.sub.2:methanol then 20:1 CH.sub.2Cl.sub.2:methanol)
gives
4-(3-isobutyl-1-methyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-8-ylmethyl)--
isoquinoline-6-carbonitrile [MH].sup.+ 389.
[0200] Method N
[0201] 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
(0.29 g, 1.9 mmol) is added to
5,6-diamino-1-isobutyl-3-methyl-1H-pyrimidine-2,4-dione (0.40 g,
1.9 mmol)) and (1-chloro-6,7-dmethoxy-isoquinolin-4-yl)-acetic acid
(0.39 g, 1.78 mmol) in methanol and water and the mixture is
stirred at ambient temperature for 2 hours. The methanol is
evaporated and the resultant solid collected by filtration and
recrystalised from ethylacetate/methanol. The resulting solid is
heated in a sealed tube (100.degree. C., 8 h) with 40% aqueous
dimethylamine. The mixture is evaporated and extracted with
ethylacetate. The ethylacetate solution is then washed with water
and brine, dried over sodium sulphate, filtered and concentrated.
Further purification by flash silica column chromatography (eluant:
ethylacetate/methanol) yields
8-(1-dimethylamino-6,7-dimethoxy-isoquinolin-4-ylmethyl)-3-isobutyl-1-met-
hyl-3,7-dihydro-purine-2,6-dione, MH.sup.+ 467.
[0202] Method O
[0203] 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
(0.29 g, 1.9 mmol) is added to
5,6-diamino-1-isobutyl-3-methyl-1H-pyrimidine-2,4-dione (0.40 g,
1.9 mmol)) and (1-chloro-6,7-dimethoxy-isoquinolin-4-yl)-acetic
acid (0.39 g, 1.78 mmol) in methanol and water and the mixture is
stirred at ambient temperature for 2 hours. The methanol is
evaporated and the resultant solid collected by filtration and
recrystalised from ethylacetate/methanol. The resulting solid is
heated under reflux with piperidine for 8 h. The solution is
filtered and the resulting solution washed with water and brine,
dried over sodium sulphate, filtered and concentrated. Further
purification by flash silica column chromatography (eluant:
ethylacetate/methanol) yields a solid which is dissolved 20% 1N
NaOH/methanol and heated to reflux for 2 h. Concentration, addition
of water and extraction with ethyl acetate gives an organic
fraction which is washed with water and brine, dried over Na2SO4,
filtered and concentrated to give
8-(6,7dimethoxy-1-piperidin-1-yl-isoquinolin-4-ylmethyl)-3-isobutyl-1-met-
hyl-3,7-dihydro-purine-2,6-dione, MH.sup.+ 507.
[0204] NMR data for Examples (.sup.1H 400 MHz DMSO-d6)
EXAMPLE 12
[0205] .delta. 3.25 (s 3H), 3.92 (s 3H), 4.02 (s 3H), 4.65 (s 2H),
7.70 (s 1H), 7.88 (s 1H), 8.45 (s 1H), 9.42 (s 1H), 11.1 (s 1H),
13.60 (s 1H)
EXAMPLE 13
[0206] .delta.320 (s 3H), 4.95 (s 3H), 4.00 (s 3H), 4.52 (d J 4
2H), 4.70 (s 2H), 5.04 (d J 18 1H), 5.09 (d J 10 1H), 5.88 (m 1H),
7.60 (s 1H), 7.88 (s 1H), 8.46 (s 1H), 9.42 (s 1H), 13.7 (s
1H).
EXAMPLE 14
[0207] .delta. 0.20-0.40 (m 4H), 1.10-1.30 (m 1H), 3.21 (s 3H),
3.81 (m 2H), 3.98 (s 3H), 4.03 (s 3H), 4.66 (s 2H), 7.65 (s 1H),
7.85 (s 1H), 8.45 (s 1H), 9.39 (s 1H), 13.70 (s 1H).
EXAMPLE 15
[0208] .delta. 0.82 (s 9H), 3.20 (s 3H), 3.78 (s 2H), 3.99 (s 3H),
4.04 (s 3H), 7.62 (s 1H), 7.90 (s, 1H), 8.45 (s 1H), 9.44 (s 1H),
13.60 (s 1H).
EXAMPLE 16
[0209] .delta. 0.81 (d J 7 12H), 1.98 (m 1H), 2.12 (m 1H), 3.70 (d
J 8 2H), 3.78 (d J 7 2H), 3.99 (s 3H), 4.05 (s 3H), 4.70 (s 2H),
7.65 (s 1H), 7.90 (s 1H), 8.46 (s 1H), 9.45 (s 1H), 13.6 (s
1H).
EXAMPLE 17
[0210] .delta. 0.80-1.10 (m 6H), 1.40-1.60 (m 4H), 1.80 (m 1H),
3.15 (s 1H), 3.76 (d J 8 2H), 3.91 (s 3H), 4.02 (s 3H), 4.68 (s
2H), 7.60 (s 1H), 7.88 (s 1H), 8.44 (s 1H), 13.60 (s 1H).
EXAMPLE 18
[0211] .delta. 1.69 (s 3H), 3.21 (s 3H), 3.98 (s 3H), 4.01 (s 3H),
4.46 (s 2H), 4.52 (s 1H), 4.68 (s 2H), 4.76 (s 1H), 7.58 (s 1H),
7.84 (s 1H), 8.45 (s 1H), 9.42 (s 1H), 13.60 (s 1H).
EXAMPLE 19
[0212] .delta. 1.50-1.85 (m 4H), 3.18 (s 3H), 3.50-3.85 (m 4H),
3.95 (s 3H), 4.02 (s 3H), 4.10-4.20 (m 1H), 4.70 (s 2H), 7.75 (s
1H), 7.920 (s 1H), 8.50 (s 1H), 9.50 (s 1H), 13.60 (br s 1H).
EXAMPLE 20
[0213] .delta. 0.70-0.80 (m 6H), 0.99-1.10 (m 1H), 1.20-1.25 (m
1H), 1.88-2.00 (m 1H), 3.21 (s 3H), 3.64-3.80 (m 2H), 3.95 (s 3H),
4.00 (s 3H), 4.68 (s 2H), 7.60 (s 1H), 7.80 (s 1H), 8.45 (s 1H),
9.42 (s 1H), 13.60 (br s 1H).
EXAMPLE 21
[0214] .delta. 0.83 (t J 8 3H), 1.63 (sextet J 8 2H), 3.83 (t J 8
2H), 3.99 (s 3H), 4.05 (s 3H), 4.69 (s 2H), 7.64 (s 1H), 7.88 (s
1H), 8.44 (s 1H), 9.42 (s 1H), 11.10 (s 1H), 13.60 (s 1H).
EXAMPLE 23
[0215] .delta. 0.80 (d J 7 6H), 3.18 (s 3H), 3.75 (d J 8 2H), 4.60
(s 2H), 6.32 (s 2H), 7.71 (s 1H), 7.82 (s 1H), 8.50 (s 1H), 9.42 (s
1H), 13.50 (s 1H).
EXAMPLE 49
[0216] .delta. 0.12-0.25 (m 4H), 1.02-1.10 (m 1H), 3.20 (s 3H),
3.68 (d J 7 2H), 4.00 (s 3H), 4.80 (s 2H), 7.70 (d J 9 1H), 8.21 (d
J 9 1H), 8.38 (s 1H), 9.20 (s 1H), 13.10 (s 1H).
EXAMPLE 86
3-Isobutyl-1-methyl-8-[1-(6-methyl-5-oxo-5,6-dihydro-[1,3]dioxolo[4,5-.g.]-
isoquinolin-8-yl)-ethyl]-3,7-dihydro-purine-2,6-dione
[0217] Benzo[1,3]dioxol-5-ylmethyl-(2,2-dimethoxy-ethyl)-amine
(Tetrahedron 1968, 24, 1467) is treated with pyruvic acid according
to the general procedure for Intermediate 22 to afford
2-[1,3]dioxolo[4,5-.g.]isoquinolin-8-yl-propionic acid
hydrochloride, mp 224-226.degree. C. Treatment with HCl gas in
ethanol affords the corresponding ethyl ester hydrochloride, mp
223-225.degree. C. A solution of this compound (2.73 g, 10 mmol) in
benzene (20 ml) is treated with dimethyl sulfate (1.26 g, 10 mmol),
stirred at room temperature for 5 hours and the solvent is
evaporated. The crude oil is dissolved in water (20 ml), cooled to
0-5.degree. C. and a solution of K.sub.3Fe(CN).sub.6 (5.72 g, 17.4
mmol) in water (25 ml) and sodium hydroxide (2.04 g, 51 mmol) in
water (15 ml) are added. After 1.5 hours at 5.degree. C., the
reaction is adjusted to pH 2 with concentrated hydrochloric acid
and the product collected by filtration then crystallised from
methanol-dichloromethane to afford
2-(6-methyl-5-oxo-5,6-dihydro-[1,3]dioxolo[4,5-.g.]isoquinolin-8-yl)-prop-
ionic acid, mp 290.degree. C. (dec). This intermediate is then
converted to the xanthine according to the general procedure of
Method D, [MH].sup.+ 452.
EXAMPLE 87
8-(6,7-Dimethoxy-quinolin-4-ylmethyl)-3-isobutyl-1-methyl-3,7-dihydro-puri-
ne-2,6-dione
[0218] Lithium diisopropylamide (2M pentane solution 2.46 ml, 4.92
mmol) and potassium t-butoxide (0.552 g, 4.92 mmol) are added to
THF (10 ml) at -70.degree. C., followed by
6,7-dimethoxy-4-methyl-quinoline [J. Org. Chem., 1997, 623, 568]
(1.0 g, 4.92 mmol). After 1 hour the reaction is poured on to an
excess of crushed dry ice and warmed to room temperature overnight.
Pyridine hydrochloride (0.57 g, 4.92 mmol) is added and the
reaction partitioned between ether and water. The aqueous phase is
evaporated, taken into hot methanol, treated with charcoal,
filtered through celite and evaporated to afford
(6,7-dimethoxy-quinolin-4-yl)-acetic acid, MH.sup.+ 248. This
intermediate is then converted to the xanthine acording to the
general procedure of Method C, mp>250.degree. C.
* * * * *