U.S. patent application number 16/733174 was filed with the patent office on 2020-05-07 for organic compounds.
The applicant listed for this patent is INTRA-CELLULAR THERAPIES, INC.. Invention is credited to Peng LI, Jun ZHAO, Hailin ZHENG.
Application Number | 20200138820 16/733174 |
Document ID | / |
Family ID | 47296522 |
Filed Date | 2020-05-07 |
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United States Patent
Application |
20200138820 |
Kind Code |
A1 |
LI; Peng ; et al. |
May 7, 2020 |
ORGANIC COMPOUNDS
Abstract
The present invention relates to PDEI inhibitory compounds of
Formula I as described herein, processes for their production,
their use as pharmaceuticals and pharmaceutical compositions
comprising them.
Inventors: |
LI; Peng; (New Milford,
NJ) ; ZHENG; Hailin; (New York, NY) ; ZHAO;
Jun; (Highland Park, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTRA-CELLULAR THERAPIES, INC. |
New York |
NY |
US |
|
|
Family ID: |
47296522 |
Appl. No.: |
16/733174 |
Filed: |
January 2, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14125017 |
Mar 17, 2014 |
10561656 |
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PCT/US2012/041925 |
Jun 11, 2012 |
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16733174 |
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61495683 |
Jun 10, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61P 19/10 20180101;
A61P 27/06 20180101; A61P 11/02 20180101; A61P 25/14 20180101; A61P
25/18 20180101; C07D 487/12 20130101; A61P 25/30 20180101; A61P
25/00 20180101; A61K 31/565 20130101; A61P 25/28 20180101; A61K
31/57 20130101; A61P 11/06 20180101; A61K 31/165 20130101; A61P
15/08 20180101; A61P 9/10 20180101; A61P 25/20 20180101; A61K 8/69
20130101; A61K 31/565 20130101; A61K 31/19 20130101; A61P 15/10
20180101; A61P 9/00 20180101; A61P 21/02 20180101; A61P 29/00
20180101; A61P 27/02 20180101; A61P 9/12 20180101; A61P 37/08
20180101; A61P 11/00 20180101; A61P 37/06 20180101; A61P 25/16
20180101; A61K 31/57 20130101; A61K 31/19 20130101; A61P 15/00
20180101; C07D 487/14 20130101; A61K 9/0048 20130101; A61K 31/165
20130101; A61P 25/24 20180101; A61Q 7/00 20130101; A61K 45/06
20130101; A61K 31/519 20130101; A61P 5/14 20180101; A61P 35/00
20180101; A61K 2300/00 20130101; A61K 2300/00 20130101; A61K
2300/00 20130101; A61K 2300/00 20130101 |
International
Class: |
A61K 31/519 20060101
A61K031/519; C07D 487/14 20060101 C07D487/14; A61Q 7/00 20060101
A61Q007/00; A61K 31/165 20060101 A61K031/165; A61K 31/57 20060101
A61K031/57; A61K 8/69 20060101 A61K008/69; A61K 9/00 20060101
A61K009/00; A61K 45/06 20060101 A61K045/06; A61K 31/565 20060101
A61K031/565; A61K 31/19 20060101 A61K031/19; C07D 487/12 20060101
C07D487/12 |
Claims
1. A Compound of Formula I ##STR00029## wherein (i) R.sub.1 is H or
C.sub.1-4 alkyl; (ii) R.sub.4 is H and R.sub.2 and R.sub.3 are
independently H or C.sub.1-6alkyl; or R.sub.2 is H and R.sub.3 and
R.sub.4 together form a di-, tri- or tetramethylene bridge; (iii)
R.sub.5 is attached to one of the nitrogens on the pyrazolo portion
of Formula I and is a moiety of Formula A ##STR00030## wherein: X,
Y and Z are C; R.sub.8, R.sub.9, R.sub.11 and R.sub.12 are H; and
R.sub.10 is heteroaryl, optionally substituted with one or more
halo; (iv) R.sub.6 is ethyl or isopropyl, in free or form.
2. The compound according to claim 1, selected from any of the
following ##STR00031## in free or salt form.
3. The compound according to claim 1, wherein R.sub.4 is H and
R.sub.2 and R.sub.3 are independently H or C.sub.1-6alkyl, in free
or salt form.
4. The compound according to claim 1, wherein the compound is a
compound of Formula I(i): ##STR00032## wherein (i) R.sub.1 is
C.sub.1-4 alkyl; (ii) R.sub.4 is H and R.sub.2 and R.sub.3 are
independently C.sub.1-6alkyl; (iii) R.sub.5 is attached to one of
the nitrogens on the pyrazolo portion of Formula I(i) and is a
moiety of Formula A ##STR00033## wherein: X, Y and Z are C;
R.sub.8, R.sub.9, R.sub.11 and R.sub.12 are H; and R.sub.10 is
pyridyl, substituted with one or more halo; (iv) R.sub.6 is ethyl
or isopropyl; in free or form.
5. The compound according to claim 4, selected from any of the
following ##STR00034## in free or salt form.
6. The compound according to claim 1, wherein R.sub.2 is H and
R.sub.3 and R.sub.4 together form a di-, tri- or tetramethylene
bridge, in free or salt form.
7. The compound according to claim 6, wherein R.sub.2 is H and
R.sub.3 and R.sub.4 together form a tri-methylene bridge and the
carbons carrying R.sub.3 and R.sub.4 have the R and S
configurations, respectively, in free or salt form.
8. The compound according to claim 6, selected from any of the
following: ##STR00035## in free or salt form.
9. A pharmaceutical composition comprising the compound according
to claim 1, in free or pharmaceutically acceptable salt form, in
admixture with a pharmaceutically acceptable diluent or
carrier.
10. A method of treating any of the following conditions:
Parkinson's disease, restless leg, tremors, dyskinesias,
Huntington's disease, Alzheimer's disease, drug-induced movement
disorders, depression, attention deficit disorder, attention
deficit hyperactivity disorder, bipolar illness, anxiety, sleep
disorder, narcolepsy, cognitive impairment, e.g., cognitive
impairment of schizophrenia, dementia, Tourette's syndrome, autism,
fragile X syndrome, psychostimulant withdrawal, and/or drug
addiction, cerebrovascular disease, stroke, congestive heart
disease, hypertension, pulmonary hypertension, and/or sexual
dysfunction; asthma, chronic obstructive pulmonary disease,
allergic rhinitis, autoimmune disease, inflammatory diseases;
female sexual dysfunction, exercise amenorrhoea, anovulation,
menopause, menopausal symptoms, hypothyroidism, pre-menstrual
syndrome, premature labor, infertility, irregular menstrual cycles,
abnormal uterine bleeding, osteoporosis, multiple sclerosis,
prostate enlargement, prostate cancer, hypothyroidism,
estrogen-induced endometrial hyperplasia or carcinoma, glaucoma and
elevated intraocular pressure, psychosis, e.g., schizophrenia,
schizoaffective disorder, schizophreniform disorder, psychotic
disorder, delusional disorder, and mania, such as in acute manic
episodes and bipolar disorder, traumatic brain injury, and/or any
disease or condition characterized by low levels of cAMP and/or
cGMP (or inhibition of cAMP and/or cGMP signaling pathways) in
cells expressing PDE1, and/or by reduced dopamine D1 receptor
signaling activity; and/or any disease or condition that may be
ameliorated by the enhancement of progesterone signaling;
comprising administering an effective amount of the compound
according to claim 1, in free or pharmaceutically acceptable salt
form, to a patient in need of such treatment.
11. The method of claim 10, wherein the condition is Parkinson's
disease.
12. The method of claim 10, wherein the condition is cognitive
impairment.
13. The method of claim 10, wherein the condition is cognitive
impairment of schizophrenia.
14. The method of claim 10, wherein the condition is
narcolepsy.
15. The method of claim 14 further comprising administering a
compound or compounds selected from central nervous system
stimulants, modafinil, antidepressants, and gamma hydroxybutyrate,
to a patient in need thereof.
16. The method of claim 10, wherein said condition is female sexual
dysfunction.
17. The method of claim 16, further comprising administering a
compound or compounds selected from a group consisting of
estradiol, estriol, estradiol esters, progesterone and progestins
to a patient in need thereof.
18. A method for the treatment of treatment for glaucoma or
elevated intraocular pressure comprising topical administration of
a therapeutically effective amount of a compound according to claim
1, in free or pharmaceutically acceptable salt form, in an
opthalmically compatible carrier to the eye of a patient in need
thereof.
19. A method for the treatment of psychosis, schizophrenia,
schizoaffective disorder, schizophreniform disorder, psychotic
disorder, delusional disorder, and mania, such as in acute manic
episodes and bipolar disorder, comprising administering a
therapeutically effective amount of a compound according to claim
1, in free or pharmaceutically acceptable salt form, to a patient
in need thereof.
20. A method for the treatment of traumatic brain injury comprising
administering to a patient in need thereof, a therapeutically
effective amount of the compound according to claim 1, in free or
pharmaceutically acceptable salt form.
21. A method for lengthening or enhancing growth of the eyelashes
by administering an effective amount of a prostaglandin analogue,
e.g., bimatoprost, concomitantly, simultaneously or sequentially
with an effective amount of a compound according to any claim 1, in
free or salt form.
22. (canceled)
23. (canceled)
24. (canceled)
Description
[0001] This application claims priority from U.S. Provisional
Application No. 61/495,683, filed Jun. 10, 2011, the contents of
which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to PDE1 inhibitory compounds
of Formula I as described below, processes for their production,
their use as pharmaceuticals and pharmaceutical compositions
comprising them. These compounds are useful e.g., in the treatment
of diseases involving disorders of the dopamine D1 receptor
intracellular pathway, such as Parkinson's disease, depression,
narcolepsy, psychosis, damage to cognitive function, e.g., in
schizophrenia, or disorders that may be ameliorated through
enhanced progesterone-signaling pathway, e.g., female sexual
dysfunction.
BACKGROUND OF THE INVENTION
[0003] Eleven families of phosphodiesterases (PDEs) have been
identified but only PDEs in Family I, the
Ca.sup.2+-calmodulin-dependent phosphodiesterases (CaM-PDEs), have
been shown to mediate both the calcium and cyclic nucleotide (e.g.
cAMP and cGMP) signaling pathways. The three known CaM-PDE genes,
PDE1A, PDE1B, and PDE1C, are all expressed in human central nervous
system tissue. PDE1A is expressed in the brain with high levels in
the CA1 to CA3 layers of the hippocampus and cerebellum and at a
low level in the striatum. PDE1B is predominately expressed in the
striatum, dentate gyrus, olfactory tract and in the prefrontal
cortex colocalized with the dopamine D1 receptor. Its expression
generally correlates with brain regions having high levels of
dopaminergic innervation. Although PDE1B is primarily expressed in
the central nervous system, it is present in neutrophils. PDE1C is
more ubiquitously expressed in the brain and is expressed in the
heart and vascular smooth muscle.
[0004] Cyclic nucleotide phosphodiesterases decrease intracellular
cAMP and cGMP signaling by hydrolyzing these cyclic nucleotides to
their respective inactive 5'-monophosphates (5'AMP and 5'GMP).
CaM-PDEs play a critical role in mediating signal transduction in
brain cells, particularly within an area of the brain known as the
basal ganglia or striatum. For example, NMDA-type glutamate
receptor activation and/or dopamine D2 receptor activation result
in increased intracellular calcium concentrations, leading to
activation of effectors such as calmodulin-dependent kinase II
(CaMKII) and calcineurin and to activation of CaM-PDEs, resulting
in reduced cAMP and cGMP. Dopamine D1 receptor activation, on the
other hand, leads to activation of adenylate cyclases, resulting in
increased cAMP. This cyclic nucleotide in turn activate protein
kinase A (PKA; cAMP-dependent protein kinase). Production of cGMP
is known to occur in tissues involved in cognitive function through
various stimulations such as nitric oxide production induced by
high intra-cellular calcium levels and to subsequently activate
protein kinase G (PKG; cGMP-dependent protein kinase). PKG and PKA
phosphorylate downstream signal transduction pathway elements such
as DARPP-32 (dopamine and cAMP-regulated phosphoprotein) and cAMP
responsive element binding protein (CREB). Phosphorylated DARPP-32
in turn inhibits the activity of protein phosphates-1 (PP-1),
thereby increasing the state of phosphorylation of substrate
proteins such as progesterone receptor (PR), leading to induction
of physiologic responses. D1 receptor signaling is disrupted in
schizophrenia, contributing to cognitive impairment in the disease.
The role of cAMP and cGMP in cognitive function has been well
established in animal studies. Studies in rodents also have
suggested that inducing cAMP and cGMP synthesis through activation
of dopamine D1 or progesterone receptor enhances progesterone
signaling associated with various physiological responses,
including the lordosis response associated with receptivity to
mating in some rodents. See Mani, et al., Science (2000) 287: 1053,
the contents of which are incorporated herein by reference.
[0005] CaM-PDEs can therefore affect dopamine-regulated and other
intracellular signaling pathways in the basal ganglia (striatum),
including but not limited to nitric oxide, noradrenergic,
neurotensin, CCK, VIP, serotonin, glutamate (e.g., NMDA receptor,
AMPA receptor), GABA, acetylcholine, adenosirie (e.g., A2A
receptor), cannabinoid receptor, natriuretic peptide (e.g., ANP,
BNP, CNP), DARPP-32, and endorphin intracellular signaling
pathways.
[0006] Phosphodiesterase (PDE) activity, in particular,
phosphodiesterase I (PDE1) activity, functions in brain tissue as a
regulator of locomotor activity and learning and memory. PDE1 is a
therapeutic target for regulation of intracellular signaling
pathways, preferably in the nervous system, including but not
limited to a dopamine D1 receptor, dopamine D2 receptor, nitric
oxide, noradrenergic, neurotensin, CCK, VIP, serotonin, glutamate
(e.g., NMDA receptor, AMPA receptor), GABA, acetylcholine,
adenosine (e.g., A2A receptor), cannabinoid receptor, natriuretic
peptide (e.g., ANP, BNP, CNP), endorphin intracellular signaling
pathway and progesterone signaling pathway. For example, inhibition
of PDE1B should act to potentiate the effect of a dopamine D1
agonist by protecting cGMP and cAMP from degradation, and should
similarly inhibit dopamine D2 receptor signaling pathways, by
inhibiting PDE1 activity that is a consequence of D2
receptor-mediated increases in intra-cellular calcium. Chronic
elevation in intracellular calcium levels is linked to cell death
in numerous disorders, particularly in neurodegerative diseases
such as Alzheimer's, Parkinson's and Huntington's Diseases and in
disorders of the circulatory system leading to stroke and
myocardial infarction. PDE1 inhibitors are therefore potentially
useful in diseases characterized by reduced dopamine D1 receptor
signaling activity, such as Parkinson's disease, restless leg
syndrome, depression, narcolepsy and cognitive impairment such as
cognitive impairment associated with schizophrenia. PDE1 inhibitors
are also useful in diseases that may be alleviated by the
enhancement of progesterone-signaling such as female sexual
dysfunction.
[0007] There is thus a need for compounds that selectively inhibit
PDE1 activity.
SUMMARY OF THE INVENTION
[0008] The invention provides a Compound of Formula I:
##STR00001##
wherein [0009] (i) R.sub.1 is H or C.sub.1-4 alkyl (e.g., methyl or
ethyl); [0010] (ii) R.sub.4 is H and R.sub.2 and R.sub.3 are
independently H or C.sub.1-6alkyl (e.g., methyl); or [0011] R.sub.2
is H and R.sub.3 and R.sub.4 together form a di-, tri- or
tetramethylene bridge (e.g., wherein the R.sub.3 and R.sub.4
together have the cis configuration, e.g., where the carbons
carrying R.sub.3 and R.sub.4 have the R and S configurations,
respectively); [0012] (iii) R.sub.5 is attached to one of the
nitrogens on the pyrazolo portion of Formula I and is a moiety of
Formula A
[0012] ##STR00002## [0013] wherein: [0014] X, Y and Z are C; [0015]
R.sub.8, R.sub.9, R.sub.11 and R.sub.12 are H; and [0016] R.sub.10
is heteroaryl (e.g., pyridyl (for example pyrid-2-yl), optionally
substituted with one or more halo (e.g., F or Cl), for example
R.sub.10 is unsubstituted pyridyl, or pyridyl substituted with halo
(e.g., fluoro), for example R.sub.10 is selected from a group
consisting of pyridyl (for example pyrid-2-yl), 6-fluoropyrid-2-yl,
5-fluoropyrid-2-yl, 4-fluoropyrid-2-yl and 3-fluoropyrid-2-yl;
[0017] (iv) R.sub.6 is ethyl or isopropyl, in free or form.
[0018] The invention further provides compounds of Formula I as
follows: [0019] 1.1 Formula 1, wherein R.sub.1 is H or C.sub.1-4
alkyl (e.g., methyl); [0020] 1.2 Formula I or 1.1, wherein R.sub.1
is H; [0021] 1.3 Formula I or 1.1, wherein R.sub.1 is C.sub.1-4
alkyl; [0022] 1.4 Formula I or 1.1, wherein R.sub.1 is methyl;
[0023] 1.5 Formula I, or any of 1.1-1.4, wherein R.sub.4 is H and
R.sub.2 and R.sub.3 are independently H or C.sub.1-6alkyl (e.g.,
methyl); [0024] 1.6 Formula I, or any of 1.1-1.4, wherein R.sub.4
is H and R.sub.2 and R.sub.3 are both C.sub.1-6alkyl (e.g., R.sub.2
and R.sub.3 are both methyl); [0025] 1.7 Formula I or any of
1.1-1.6, wherein R.sub.10 is heteroaryl (e.g., pyridyl (for example
pyrid-2-yl), optionally substituted with one or more halo (e.g., F
or Cl), for example R.sub.10 is unsubstituted pyridyl, or pyridyl
substituted with halo (e.g., fluoro), for example R.sub.10 is
selected from a group consisting of pyridyl (for example
pyrid-2-yl), 6-fluoropyrid-2-yl, 5-fluoropyrid-2-yl,
4-fluoropyrid-2-yl and 3-fluoropyrid-2-yl; [0026] 1.8 Formula I or
any of 1.1-1.6, wherein R.sub.10 is pyridyl (e.g., pyrid-2-yl);
[0027] 1.9 Formula I or any of 1.1-1.6, wherein R.sub.10 is
6-fluoropyrid-2-yl; [0028] 1.10 Formula I or any of 1.1-1.6,
wherein R.sub.10 is 5-fluoropyrid-2-yl; [0029] 1.11 Formula I or
any of 1.1-1.6, wherein R.sub.10 is 4-fluoropyrid-2-yl; [0030] 1.12
Formula 1 or any of 1.1-1.6, wherein R.sub.10 is
3-fluoropyrid-2-yl; [0031] 1.13 Formula I or any of 1.1-1.12,
wherein R.sub.6 is ethyl; [0032] 1.14 Formula I or any of 1.1-1.12,
wherein R.sub.6 is isopropyl; [0033] 1.15 Formula I or any of
1.1-1.14, wherein R.sub.4 is H and R.sub.2 and R.sub.3 are
C.sub.1-6alkyl (e.g., methyl); or [0034] R.sub.2 is H and R.sub.3
and R.sub.4 together form a di-, tri- or tetramethylene bridge
(e.g., wherein the R.sub.3 and R.sub.4 together have the cis
configuration, e.g., where the carbons carrying R.sub.3 and R.sub.4
have the R and S configurations, respectively); [0035] 1.16 Formula
I or any of 1.1-1.14, wherein R.sub.4 is H and R.sub.2 and R.sub.3
are both methyl; [0036] 1.17 Formula I or any of 1.1-1.14, wherein
R.sub.2 is H and R.sub.3 and R.sub.4 together form a di-, tri- or
tetramethylene bridge (e.g., wherein the R.sub.3 and R.sub.4
together have the cis configuration, e.g., where the carbons
carrying R.sub.3 and R.sub.4 have the R and S configurations,
respectively); [0037] 1.18 Formula I or any of 1.1-1.14, wherein
R.sub.2 is H and R.sub.3 and R.sub.4 together form a tri-methylene
bridge (e.g., wherein the R.sub.3 and R.sub.4 together have the cis
configuration, e.g., where the carbons carrying R.sub.3 and R.sub.4
have the R and S configurations, respectively); [0038] 1.19 Formula
I or any of 1.1-1.18, wherein R.sub.4 is ethyl; [0039] 1.20 Formula
I or any of 1.1-1.18, wherein R.sub.4 is isopropyl; [0040] 1.21 any
of formulae 1.1-1.16 and 1.19-1.20, wherein the compound is
selected from a group consisting of:
[0040] ##STR00003## [0041] 1.22 any of formulae 1.1-1.15 and
1.17-1.20, wherein the compound is selected from a group consisting
of:
[0041] ##STR00004## [0042] 1.23 any of the preceding formulae
wherein the compounds inhibit phosphodiesterase-mediated (e.g.,
PDE1-mediated) hydrolysis of cGMP, e.g., with an IC.sub.50 of less
than 1 .mu.M, preferably less than 10 nM, more preferably less than
or equal to 5 nM in an immobilized-metal affinity particle reagent
PDE assay, for example, as described in Example 4, in free or salt
form.
[0043] In a particular embodiment, the invention provides a
compound of Formula 1(i):
##STR00005##
wherein [0044] (i) R.sub.r is C.sub.1-4 alkyl (e.g., methyl or
ethyl); [0045] (ii) R.sub.4 is H and R.sub.2 and R.sub.3 are
independently C.sub.1-6alkyl (e.g., methyl); [0046] (iii) R.sub.5
is attached to one of the nitrogens on the pyrazolo portion of
Formula I and is a moiety of Formula A
[0046] ##STR00006## [0047] wherein: [0048] X, Y and Z are C; [0049]
R.sub.8, R.sub.9, R.sub.11 and R.sub.12 are H; and [0050] R.sub.10
is pyridyl (for example pyrid-2-yl), substituted with one or more
halo (e.g., F or CI), for example R.sub.10 is unsubstituted
pyridyl, or pyridyl substituted with halo (e.g., fluoro), for
example R.sub.10 is selected from a group consisting of pyridyl
(for example pyrid-2-yl), 6-fluoropyrid-2-yl, S-fluoropyrid-2-yl,
4-fluoropyrid-2-yl and 3-fluoropyrid-2-yl; [0051] (iv) R.sub.6 is
ethyl or isopropyl; in free or form.
[0052] If not otherwise specified or clear from context, the
following terms herein have the following meanings: [0053] (a)
"Alkyl" as used herein is a saturated or unsaturated hydrocarbon
moiety, preferably saturated, preferably having one to six carbon
atoms, preferably having one to four carbon atoms, which may be
linear or branched, and may be optionally mono-, di- or
tri-substituted, e.g., with halogen (e.g., chloro or fluoro),
hydroxy, or carboxy. [0054] (b) "Aryl" as used herein is a mono or
bicyclic aromatic hydrocarbon, preferably phenyl, optionally
substituted, e.g., with alkyl (e.g., methyl), halogen (e.g., chloro
or fluoro), haloalkyl (e.g., trifluoromethyl), hydroxy, carboxy, or
an additional aryl or heteroaryl (e.g., biphenyl or pyridylphenyl).
[0055] (c) "Heteroaryl" as used herein is an aromatic moiety
wherein one or more of the atoms making up the aromatic ring is
sulfur or nitrogen rather than carbon, e.g., pyridyl or
thiadiazolyl, which may be optionally substituted, e.g., with
alkyl, halogen, haloalkyl, hydroxy or carboxy.
[0056] Compounds of the Invention, e.g., Compounds of Formula I or
I(i), e.g., any of formulae 1.1-1.23, may exist in free or salt
form, e.g., as acid addition salts. In this specification unless
otherwise indicated, language such as "Compounds of the Invention"
is to be understood as embracing the compounds in any form, for
example free or acid addition salt form, or where the compounds
contain acidic substituents, in base addition salt form. The
Compounds of the Invention are intended for use as pharmaceuticals,
therefore pharmaceutically acceptable salts are preferred. Salts
which are unsuitable for pharmaceutical uses may be useful, for
example, for the isolation or purification of free Compounds of the
Invention or their pharmaceutically acceptable salts, are therefore
also included.
[0057] Compounds of the Invention may in some cases also exist in
prodrug form. A prodrug form is compound which converts in the body
to a Compound of the Invention. For example when the Compounds of
the Invention contain hydroxy or carboxy substituents, these
substituents may form physiologically hydrolysable and acceptable
esters. As used herein, "physiologically hydrolysable and
acceptable ester" means esters of Compounds of the Invention which
are hydrolysable under physiological conditions to yield acids (in
the case of Compounds of the Invention which have hydroxy
substituents) or alcohols (in the case of Compounds of the
Invention which have carboxy substituents) which are themselves
physiologically tolerable at doses to be administered. Therefore,
wherein the Compound of the Invention contains a hydroxy group, for
example, Compound-OH, the acyl ester prodrug of such compound,
i.e., Compound-O--C(O)--C.sub.1-4alkyl, can hydrolyze in the body
to form physiologically hydrolysable alcohol (Compound-OH) on the
one hand and acid on the other (e.g., HOC(O)--C.sub.1-4alkyl).
Alternatively, wherein the Compound of the Invention contains a
carboxylic acid, for example, Compound-C(O)OH, the acid ester
prodrug of such compound, Compound-C(O)O--C.sub.1-4alkyl can
hydrolyze to form Compound-C(O)OH and HO--C.sub.1-4alkyl. As will
be appreciated the term thus embraces conventional pharmaceutical
prodrug forms.
[0058] The invention also provides methods of making the Compounds
of the Invention and methods of using the Compounds of the
Invention for treatment of diseases and disorders as set forth
below (especially treatment of diseases characterized by reduced
dopamine D1 receptor signaling activity, such as Parkinson's
disease, Tourette's Syndrome, Autism, fragile X syndrome, ADHD,
restless leg syndrome, depression, cognitive impairment, e.g.,
cognitive impairment of schizophrenia, narcolepsy and diseases that
may be alleviated by the enhancement of progesterone-signaling such
as female sexual dysfunction or a disease or disorder such as
psychosis or glaucoma). This list is not intended to be exhaustive
and may include other diseases and disorders as set forth
below.
[0059] In another embodiment, the invention further provides a
pharmaceutical composition comprising a Compound of the Invention,
in free, pharmaceutically acceptable salt or prodrug form, in
admixture with a pharmaceutically acceptable carrier.
DETAILED DESCRIPTION OF THE INVENTION
Methods of Making Compounds of the Invention
[0060] The compounds of the Invention and their pharmaceutically
acceptable salts may be made using the methods as described and
exemplified herein and by methods similar thereto and by methods
known in the chemical art. Such methods include, but not limited
to, those described below. If not commercially available, starting
materials for these processes may be made by procedures, which are
selected from the chemical art using techniques which are similar
or analogous to the synthesis of known compounds. Various starting
materials, intermediates and/or Compounds of the Invention may be
prepared using methods described or similarly described in WO
2006/133261, WO 2009/075784 and/or WO 2010/065149. All references
cited herein are hereby incorporated by reference in their
entirety.
[0061] The Compounds of the Invention include their enantiomers,
diastereoisomers and racemates, as well as their polymorphs,
hydrates, solvates and complexes. Some individual compounds within
the scope of this invention may contain double bonds.
Representations of double bonds in this invention are meant to
include both the E and the Z isomer of the double bond. In
addition, some compounds within the scope of this invention may
contain one or more asymmetric centers. This invention includes the
use of any of the optically pure stereoisomers as well as any
combination of stereoisomers.
[0062] It is also intended that the Compounds of the Invention
encompass their stable and unstable isotopes. Stable isotopes are
nonradioactive isotopes which contain one additional neutron
compared to the abundant nuclides of the same species (i.e.,
element). It is expected that the activity of compounds comprising
such isotopes would be retained, and such compound would also have
utility for measuring pharmacokinetics of the non-isotopic analogs.
For example, the hydrogen atom at a certain position on the
Compounds of the Invention may be replaced with deuterium (a stable
isotope which is non-radioactive). Examples of known stable
isotopes include, but not limited to, deuterium, .sup.13C,
.sup.15N, .sup.18O. Alternatively, unstable isotopes, which are
radioactive isotopes which contain additional neutrons compared to
the abundant nuclides of the same species (i.e., element), e.g.,
.sup.123I, .sup.131I, .sup.125I, .sup.11C, .sup.18F, may replace
the corresponding abundant species of I, C and F. Another example.
of useful isotope of the compound of the invention is the .sup.11C
isotope. These radio isotopes are useful for radio-imaging and/or
pharmacokinetic studies of the compounds of the invention. Methods
of making isotopes of PDE1 inhibitors disclosed in WO 2011/043816,
the contents of which are incorporated by reference in their
entirety, may be used for making the isotopes of the compounds of
the current invention.
[0063] Melting points are uncorrected and (dec) indicates
decomposition. Temperature are given in degrees Celsius (.degree.
C.); unless otherwise stated, operations are carried out at room or
ambient temperature, that is, at a temperature in the range of
18-25.degree. C. Chromatography means flash chromatography on
silica gel; thin layer chromatography (TLC) is carried out on
silica gel plates. NMR data is in the delta values of major
diagnostic protons, given in parts per million (ppm) relative to
tetramethylsilane (TMS) as an internal standard. Conventional
abbreviations for signal shape are used. Coupling constants (J) are
given in Hz. For mass spectra (MS), the lowest mass major ion is
reported for molecules where isotope splitting results in multiple
mass spectral peaks-Solvent mixture compositions are given as
volume percentages or volume ratios. In cases where the NMR spectra
are complex, only diagnostic signals are reported.
Terms and Abbreviations
[0064] BuLi=n-butyllithium [0065] Bu.sup.tOH=tert-butyl alcohol,
[0066] CAN=ammonium cerium (IV) nitrate, [0067]
DIPEA=diisopropylethylamine, [0068] DMF=N,N-dimethylforanunide,
[0069] DMSO=dimethyl sulfoxide, [0070] Et.sub.2O=diethyl ether,
[0071] EtOAc=ethyl acetate, [0072] equiv.=equivalent(s), [0073]
h=hour(s), [0074] HPLC=high performance liquid chromatography,
[0075] LDA=lithium diisopropylamide [0076] MeOH=methanol, [0077]
NBS=N-bromosuccinimide [0078] NCS=N-chlorosuccinimide [0079]
NaHCO.sub.3=sodium bicarbonate, [0080] NH.sub.4OH=ammonium
hydroxide, [0081]
Pd.sub.2(dba).sub.3=tris[dibenzylideneacetone]dipalladium(0) [0082]
PMB=p-methoxybenzyl, [0083] POCl.sub.3=phosphorous oxychloride,
[0084] SOCl.sub.2=thionyl chloride, [0085] TFA=trifluoroacetic
acid, [0086] TFMSA=trifluoromethanesulfonic acid [0087]
THF=tetrahedrofuran.
[0088] The synthetic methods in this invention are illustrated
below. The significances for the R groups are as set forth above
for formula I or I(i) or any of formulae 1.1-1.23, unless otherwise
indicated.
[0089] In an aspect of the invention, intermediate compounds of
formula IIb can be synthesized by reacting a compound of formula Ha
with a dicarboxylic acid, acetic anhydride and acetic acid mixing
with heat, e.g., heating to about 90.degree. C. for about 3 hours
and then cooled:
##STR00007##
wherein R.sup.1 is C.sub.1-4alkyl, e.g., methyl.
[0090] Intermediate He can be prepared by for example reacting a
compound of IIb with for example a chlorinating compound such as
POCl.sub.3, sometimes with small amounts of water and heat, e.g.,
heating to about 80.degree. C. for about 4 hours and then
cooled
##STR00008##
[0091] Intermediate lid may be formed by reacting a compound of IIc
with for example a P.sup.1--X in a solvent such as DMF and a base
such as K.sub.2CO.sub.3 at room temperature or with heating:
##STR00009##
wherein P.sup.1 is a protective group [e.g., p-methoxybenzyl group
(PMB)]; X is a leaving group such as a halogen, mesylate, or
tosylate. Preferably P.sup.1 is paramethoxybenzyl (PMB) and base is
potassium carbonate.
[0092] Intermediate IIe may be prepared by reacting a compound of
IId with hydrazine or hydrazine hydrate in a solvent such as
methanol and refluxed, e.g., for about 4 hours and then cooled:
##STR00010##
[0093] Intermediate IVa may be formed by for example reacting a
compound of IIe with POCl.sub.3 and DMF:
##STR00011##
wherein R.sup.1 is as defined previously in Formula I, I(i) or any
of formulae 1.1-1.23, e.g., such as a methyl group.
[0094] Intermediate IVb may be formed by reacting a compound of IVa
with for example a R.sub.5--X in a solvent such as DMF and a base
such as K.sub.2CO.sub.3 at room temperature or with heating
(Reaction 1):
##STR00012##
[0095] Intermediate IVc may be synthesized from a compound of IVb
by removing the protective group P.sup.1 with an appropriate
method. For example, if P.sup.1 is a PMB group, then it can be
removed with CAN or TFA/TFMSA at room temperature (Reaction 2):
##STR00013##
Wherein P.sup.1 is BOC, the compound may be deprotected by using
acid such as hydrochloric acid or TFA.
[0096] Intermediate IVd can be prepared by reacting a compound of
IVc with for example a chlorinating compound such as POCl.sub.3 and
refluxed for about 2 days, or heated at 150-200.degree. C. for
about 10 min in a sealed vial with a microwave instrument and then
cooled (Reaction 3):
##STR00014##
[0097] Intermediate IVe can be formed by reacting a compound of IVd
with an amino alcohol under basic condition in a solvent such as
DMF and heated overnight then cooled (Reaction 4A):
##STR00015##
[0098] Alternatively, intermediate IVe can be synthesized directly
from a compound of IVe by reacting with an amino alcohol and a
coupling reagent such as BOP in the presence of a base such as DBU
(Reaction 4B):
##STR00016##
wherein all the substituents are as defined previously.
[0099] Compound IVf may be formed by reacting a compound of IVe
with for example a dehydrating/halogenating agent such as
SOCl.sub.2 in a solvent such as CH.sub.2Cl.sub.2 at room
temperature overnight or heated at 35.degree. C. for several hours,
and then cooled (Reaction 5). Alternatively, Compound IVf may be
prepared by reacting Compound IVe with 4-toluenesulfonyl chloride
and pyridine.
##STR00017##
[0100] Compound IVg wherein X is halogen (e.g., chloro, bromo or
iodo) may be formed by reacting a compound of IVf with for example
a halogenating agent such as NCS, NBS or I.sub.2 and a base such as
LDA or n-BuLi (for example, NCS in the presence of LDA) in a
solvent such as THF at low temperature for several hours (Reaction
6).
##STR00018##
[0101] Alternatively, Compound IVg may be formed by reacting a
compound of IVf with for example a halogenating agent such as
hexachloroethane and a base such as LiHMDS in a solvent such as THF
at low temperature for several hours (Reaction 6):
##STR00019##
[0102] Compound of Formula I or any of formulae 1.1-1.23 may be
formed by reacting a compound of IVg with R.sub.6--SH wherein R. is
defined in Formula 1, in the presence of a base (e.g., potassium
carbonate) with heating, e.g., in a sealed tube and heated with
stirring in a microwave reactor at 4 Barr, e.g., at 150.degree. C.
for 1 hour.
##STR00020##
[0103] Alternatively, compound of Formula I may be formed by
reacting a compound of IVf with a disulfide R.sub.6--S--S--R.sub.6
in the presence of a strong base, such as a lithium reagent (e.g.
LiHMDS) in a solvent such as THF.
[0104] Alternatively, the Compounds of Formula I may be prepared,
for example, by reacting Compound I-A with, for example,
R.sub.5--X, in a solvent such as DMF and a base such as
K.sub.2CO.sub.3 at room temperature or with heating:
##STR00021##
wherein all the substitutents are as defined previously (e.g.,
wherein R.sub.1-R.sub.6 are previously defined in Formula I or I(i)
or any of formulae 1.1-1.23); X is a leaving group such as a
halogen, mesylate, or tosylate.
[0105] The invention therefore provides a method of preparing a
compound of Formula I comprising reacting the Compound 1-A with
R.sub.5--X at room temperature or with heating. In a further
embodiment, this method further comprises the presence of a base
such as K.sub.2CO.sub.3:
##STR00022##
[0106] In another aspect, the invention provides a method of
preparing a compound of Formula I or I(i) or any of comprising
reacting a compound of IVg with R.sub.6--SH in the presence of a
base (e.g., potassium carbonate) with heating, e.g., in a sealed
tube and heated with stirring in a microwave reactor at 4 Barr,
e.g., at 150.degree. C. for 1 hour.
##STR00023##
[0107] Methods of Using Compounds of the Invention
[0108] The Compounds of the Invention are useful in the treatment
of diseases characterized by disruption of or damage to cAMP and
cGMP mediated pathways, e.g., as a result of increased expression
of PDE1 or decreased expression of cAMP and cGMP due to inhibition
or reduced levels of inducers of cyclic nucleotide synthesis, such
as dopamine and nitric oxide (NO). By preventing the degradation of
cAMP and cGMP by PDE1, thereby increasing intracellular levels of
cAMP and cGMP, the Compounds of the Invention potentiate the
activity of cyclic nucleotide synthesis inducers.
[0109] The invention provides methods of treatment of any one or
more of the following conditions: [0110] (i) Neurodegenerative
diseases, including Parkinson's disease, restless leg, tremors,
dyskinesias, Huntington's disease, Alzheimer's disease, and
drug-induced movement disorders; [0111] (ii) Mental disorders,
including depression, attention deficit disorder, attention deficit
hyperactivity disorder, bipolar illness, anxiety, sleep disorders,
e.g., narcolepsy, cognitive impairment, e.g., cognitive impairment
of schizophrenia, dementia, Tourette's syndrome, autism, fragile X
syndrome, psychostimulant withdrawal, and drug addiction; [0112]
(iii) Circulatory and cardiovascular disorders, including
cerebrovascular disease, stroke, congestive heart disease,
hypertension, pulmonary hypertension, and sexual dysfunction;
[0113] (iv) Respiratory and inflammatory disorders, including
asthma, chronic obstructive pulmonary disease, and allergic
rhinitis, as well as autoimmune and inflammatory diseases; [0114]
(v) diseases that may be alleviated by the enhancement of
progesterone-signaling such as female sexual dysfunction; [0115]
(vi) a disease or disorder such as psychosis or glaucoma; [0116]
(vii) Any disease or condition characterized by low levels of cAMP
and/or cGMP (or inhibition of cAMP and/or cGMP signaling pathways)
in cells expressing PDE1; and/or [0117] (viii) Any disease or
condition characterized by reduced dopamine D1 receptor signaling
activity, comprising administering an effective amount of a
Compound of the Invention, e.g., a compound according to any of
Formula I, I(i) or any of 1.1-1.23, in free, pharmaceutically
acceptable salt or prodrug form, to a human or animal patient in
need thereof.
[0118] In an especially preferred embodiment, the invention
provides methods of treatment or prophylaxis for narcolepsy. In
this embodiment, PDE 1 Inhibitors may be used as a sole therapeutic
agent, but may also be used in combination or for co-administration
with other active agents. Thus, the invention further comprises a
method of treating narcolepsy comprising administering
simultaneously, sequentially, or contemporaneously administering
therapeutically effective amounts of [0119] (i) a PDE 1 Inhibitor,
e.g., a compound according to any of Formula 1, 1(i) or any of
1.1-1.23, and [0120] (ii) a compound to promote wakefulness or
regulate sleep, e.g., selected from (a) central nervous system
stimulants-amphetamines and amphetamine like compounds, e.g.,
methylphenidate, dextroamphetamine, methamphetamine, and pemoline;
(b) modafinil, (c) antidepressants, e.g., tricyclics (including
imipramine, desipramine, clomipramine, and protriptyline) and
selective serotonin reuptake inhibitors (including fluoxetine and
sertraline); and/or (d) gamma hydroxybutyrate (GHB). in free,
pharmaceutically acceptable salt or prodrug form, to a human or
animal patient in need thereof.
[0121] In another embodiment, the invention further provides
methods of treatment or prophylaxis of a condition which may be
alleviated by the enhancement of the progesterone signaling
comprising administering an effective amount of a Compound of the
Invention, e.g., a compound according to any of Formula I or any of
any of 1.1-1.23, in free, pharmaceutically acceptable salt or
prodrug form, to a human or animal patient in need thereof. Disease
or condition that may be ameliorated by enhancement of progesterone
signaling include, but are not limited to, female sexual
dysfunction, secondary amenorrhea (e.g., exercise amenorrhoea,
anovulation, menopause, menopausal symptoms, hypothyroidism),
pre-menstrual syndrome, premature labor, infertility, for example
infertility due to repeated miscarriage, irregular menstrual
cycles, abnormal uterine bleeding, osteoporosis, autoimmmune
disease, multiple sclerosis, prostate enlargement, prostate cancer,
and hypothyroidism. For example, by enhancing progesterone
signaling, the PDE 1 inhibitors may be used to encourage egg
implantation through effects on the lining of uterus, and to help
maintain pregnancy in women who are prone to miscarriage due to
immune response to pregnancy or low progesterone function. The
novel PDE 1 inhibitors, e.g., as described herein, may also be
useful to enhance the effectiveness of hormone replacement therapy,
e.g., administered in combination with estrogen/estradiol/estriol
and/or progesterone/progestins in postmenopausal women, and
estrogen-induced endometrial hyperplasia and carcinoma. The methods
of the invention are also useful for animal breeding, for example
to induce sexual receptivity and/or estrus in a nonhuman female
mammal to be bred.
[0122] In this embodiment, PDE a Inhibitors may be used in the
foregoing methods of treatment or prophylaxis as a sole therapeutic
agent, but may also be used in combination or for co-administration
with other active agents, for example in conjunction with hormone
replacement therapy. Thus, the invention further comprises a method
of treating disorders that may be ameliorated by enhancement of
progesterone signaling comprising administering simultaneously,
sequentially, or contemporaneously administering therapeutically
effective amounts of [0123] (i) a PDE 1 Inhibitor, e.g., a compound
according to any of Formula I or any of any of 1.1-1.23, and [0124]
(ii) a hormone, e.g., selected from estrogen and estrogen analogues
(e.g., estradiol, estriol, estradiol esters) and progesterone and
progesterone analogues (e.g., progestins) in free, pharmaceutically
acceptable salt or prodrug form, to a human or animal patient in
need thereof.
[0125] The invention also provides a method for enhancing or
potentiating dopamine D1 intracellular signaling activity in a cell
or tissue comprising contacting said cell or tissue with an amount
of a Compound of the Invention, e.g., Formula I, I(i) or any of any
of 1.1-1.23, sufficient to inhibit PDE1 activity.
[0126] The invention also provides a method for treating a
PDE1-related, disorder, a dopamine D1 receptor intracellular
signaling pathway disorder, or disorders that may be alleviated by
the enhancement of the progesterone signaling pathway in a patient
in need thereof comprising administering to the patient an
effective amount of a Compound of the Invention, e.g., Formula I,
I(i) or any of any of 1.1-1.23, in that inhibits PDE1, wherein PDE1
activity modulates phosphorylation of DARPP-32 and/or the GluR1
AMPA receptor.
[0127] In another aspect, the invention also provides a method for
the treatment for glaucoma or elevated intraocular pressure
comprising topical administration of a therapeutically effective
amount of a phospodiesterase type I (PDE1) Inhibitor of the
Invention, e.g., a compound of Formula I, I(i) or any of 1.1-1.23,
in free or pharmaceutically acceptable salt form, in an
opthalmically compatible carrier to the eye of a patient in need
thereof. However, treatment may alternatively include a systemic
therapy. Systemic therapy includes treatment that can directly
reach the bloodstream, or oral methods of administration, for
example.
[0128] The invention further provides a pharmaceutical composition
for topical ophthalmic use comprising a PDE1 inhibitor, e.g.,
Formula I, I(i) or any of 1.1-1.23; for example an ophthalmic
solution, suspension, cream or ointment comprising a PDE1 Inhibitor
of the Invention, e.g., Formula I, I(i) or any of 1.1-1.23, in free
or ophthamalogically acceptable salt form, in combination or
association with an ophthamologically acceptable diluent or
carrier.
[0129] Optionally, the PDE1 inhibitor may be administered
sequentially or simultaneously with a second drug useful for
treatment of glaucoma or elevated intraocular pressure. Where two
active agents are administered, the therapeutically effective
amount of each agent may be below the amount needed for activity as
monotherapy. Accordingly, a subthreshold amount (i.e., an amount
below the level necessary for efficacy as monotherapy) may be
considered therapeutically effective and also may also be referred
alternatively as an effective amount. Indeed, an advantage of
administering different agents with different mechanisms of action
and different side effect profiles may be to reduce the dosage and
side effects of either or both agents, as well as to enhance or
potentiate their activity as monotherapy.
[0130] The invention thus provides the method of treatment of a
condition selected from glaucoma and elevated intraocular pressure
comprising administering to a patient in need thereof an effective
amount, e.g., a subthreshold amount, of an agent known to lower
intraocular pressure concomitantly, simultaneously or sequentially
with an effective amount, e.g., a subthreshold amount, of a PDE1
Inhibitor of the Invention, e.g., Formula I, I(i) or any of
1.1-1.23, in free or pharmaceutically acceptable salt form, such
that amount of the agent known to lower intraocular pressure and
the amount of the PDE1 inhibitor in combination are effective to
treat the condition.
[0131] In one embodiment, one or both of the agents are
administered topically to the eye. Thus the invention provides a
method of reducing the side effects of treatment of glaucoma or
elevated intraocular pressure by administering a reduced dose of an
agent known to lower intraocular pressure concomitantly,
simultaneously or sequentially with an effective amount of a PDE1
inhibitor. However, methods other than topical administration, such
as systemic therapeutic administration, may also be utilized.
[0132] The optional additional agent or agents for use in
combination with a PDE1 inhibitor may, for example, be selected
from the existing drugs comprise typically of instillation of a
prostaglandin, pilocarpine, epinephrine, or topical beta-blocker
treatment, e.g. with timolol, as well as systemically administered
inhibitors of carbonic anhydrase, e.g. acetazolamide.
Cholinesterase inhibitors such as physostigmine and echothiopate
may also be employed and have an effect similar to that of
pilocarpine. Drugs currently used to treat glaucoma thus include,
e.g., [0133] 1. Prostaglandin analogs such as latanoprost
(Xalatan), bimatoprost (Lumigan) and travoprost (Travatan), which
increase uveoscleral outflow of aqueous humor. Bimatoprost also
increases trabecular outflow. [0134] 2. Topical beta-adrenergic
receptor antagonists such as timolol, levobunolol (Betagan), and
betaxolol, which decrease aqueous humor production by the ciliary
body. [0135] 3. Alpha.sub.2-adrenergic agonists such as brimonidine
(Alphagan), which work by a dual mechanism, decreasing aqueous
production and increasing uveo-scleral outflow. [0136] 4.
Less-selective sympathomimetics like epinephrine and dipivefrin
(Propine) increase outflow of aqueous humor through trabecular
meshwork and possibly through uveoscleral outflow pathway, probably
by a beta.sub.2-receptor agonist action. [0137] 5. Miotic agents
(pira-sympathomimetics) like pilocarpine work by contraction of the
ciliary muscle, tightening the trabecular meshwork and allowing
increased outflow of the aqueous humour. [0138] 6. Carbonic
anhydrase inhibitors like dorzolamide (Trusopt), brinzolamide
(Azopt), acetazolamide (Diamox) lower secretion of aqueous humor by
inhibiting carbonic anhydrase in the ciliary body. [0139] 7.
Physostigmine is also used to treat glaucoma and delayed gastric
emptying.
[0140] For example, the invention provides pharmaceutical
compositions comprising a PDE1 Inhibitor of the Invention, e.g.,
Formula I, I(i) or any of 1.1-1.23, and an agent selected from (i)
the prostanoids, unoprostone, latanoprost, travoprost, or
bimatoprost; (ii) an alpha adrenergic agonist such as brimonidine,
apraclonidine, or dipivefrin and (iii) a muscarinic agonist, such
as pilocarpine. For example, the invention provides ophthalmic
formulations comprising a PDE-1 Inhibitor of the Invention together
with bimatoprost, abrimonidine, brimonidine, timolol, or
combinations thereof, in free or ophthamalogically acceptable salt
form, in combination or association with an ophthamologically
acceptable diluent or carrier. In addition to selecting a
combination, however, a person of ordinary skill in the art can
select an appropriate selective receptor subtype agonist or
antagonist. For example, for alpha adrenergic agonist, one can
select an agonist selective for an alpha 1 adrenergic receptor, or
an agonist selective for an alpha.sub.2 adrenergic receptor such as
brimonidine, for example. For a beta-adrenergic receptor
antagonist, one can select an antagonist selective for either
.beta..sub.1, or .beta..sub.2, or .beta..sub.3. depending on the
appropriate therapeutic application. One can also select a
muscarinic agonist selective for a particular receptor subtype such
as M.sub.1-M.sub.5.
[0141] The PDE 1 inhibitor may be administered in the form of an
ophthalmic composition, which includes an ophthalmic solution,
cream or ointment. The ophthalmic composition may additionally
include an intraocular-pressure lowering agent.
[0142] In yet another example, the PDE-1 Inhibitors disclosed may
be combined with a subthreshold amount of an intraocular
pressure-lowering agent which may be a bimatoprost ophthalmic
solution, a brimonidine tartrate ophthalmic solution, or
brimonidine tartrate/timolol maleate ophthalmic solution.
[0143] In addition to the above-mentioned methods, it has also been
surprisingly discovered that PDE1 inhibitors are useful to treat
psychosis, for example, any conditions characterized by psychotic
symptoms such as hallucinations, paranoid or bizarre delusions, or
disorganized speech and thinking, e.g., schizophrenia,
schizoaffective disorder, schizophreniform disorder, psychotic
disorder, delusional disorder, and mania, such as in acute manic
episodes and bipolar disorder. Without intending to be bound by any
theory, it is believed that typical and atypical antipsychotic
drugs such as clozapine primarily have their antagonistic activity
at the dopamine D2 receptor. PDE1 inhibitors, however, primarily
act to enhance signaling at the dopamine D1 receptor. By enhancing
D1 receptor signaling, PDE1 inhibitors can increase NMDA receptor
function in various brain regions, for example in nucleus accumbens
neurons and in the prefrontal cortex. This enhancement of function
may be seen for example in NMDA receptors containing the NR2B
subunit, and may occur e.g., via activation of the Src and protein
kinase A family of kinases.
[0144] Therefore, the invention provides a new method for the
treatment of psychosis, e.g., schizophrenia, schizoaffective
disorder, schizophreniform disorder, psychotic disorder, delusional
disorder, and mania, such as in acute manic episodes and bipolar
disorder, comprising administering a therapeutically effective
amount of a phosphodiesterase-1 (PDE1) Inhibitor of the Invention,
e.g., Formula I, I(i) or any of 1.1-1.23, in free or
pharmaceutically acceptable salt form, to a patient in need
thereof.
[0145] PDE 1 Inhibitors may be used in the foregoing methods of
treatment prophylaxis as a sole therapeutic agent, but may also be
used in combination or for co-administration with other active
agents. Thus, the invention further comprises a method of treating
psychosis, e.g., schizophrenia, schizoaffective disorder,
schizophreniform disorder, psychotic disorder, delusional disorder,
or mania, comprising administering simultaneously, sequentially; or
contemporaneously administering therapeutically effective amounts
of: [0146] (i) a PDE 1 Inhibitor of the invention, in free or
pharmaceutically acceptable salt form; and [0147] (ii) an
antipsychotic, e.g., [0148] Typical antipsychotics, e.g., [0149]
Butyrophenones, e.g. Haloperidol (Haldol, Serenace), Droperidol
(Droleptan); [0150] Phenothiazines, e.g., Chlorpromazine
(Thorazine, Largactil), Fluphenazine (Prolixin), Perphenazine
(Trilafon), Prochlorperazine (Compazine), Thioridazine (Mellaril,
Melleril), Trifluoperazine (Stelazine), Mesoridazine, Periciazine,
Promazine, Triflupromazine (Vesprin), Levomepromazine (Nozinan),
Promethazine (Phenergan), Pimozide (Orap); [0151] Thioxanthenes,
e.g., Chlorprothixene, Flupenthixol (Depixol, Fluanxol),
Thiothixene (Navane), Zuclopenthixol (Clopixol, Acuphase); [0152]
Atypical antipsychotics, e.g., [0153] Clozapine (Clozaril),
Olanzapine (Zyprexa), Risperidone (Risperdal), Quetiapine
(Seroquel), Ziprasidone (Geodon), Amisulpride (Solian),
Paliperidone (Invega), Aripiprazole (Abilify), Bifeprunox;
norclozapine, [0154] in free or pharmaceutically acceptable salt
form, to a patient in need thereof.
[0155] In a particular embodiment, the Compounds of the Invention
are particularly useful for the treatment or prophylaxis of
schizophrenia.
[0156] Compounds of the Invention, in free or pharmaceutically
acceptable salt form, are particularly useful for the treatment of
Parkinson's disease, schizophrenia, narcolepsy, glaucoma and female
sexual dysfunction.
[0157] In still another aspect, the invention provides a method of
lengthening or enhancing growth of the eyelashes by administering
an effective amount of a prostaglandin analogue, e.g., bimatoprost,
concomitantly, simultaneously or sequentially with an effective
amount of a PDE1 inhibitor of the Invention, e.g., Formula I, I(i)
or any of 1.1-1.23, in free or pharmaceutically acceptable salt
form, to the eye of a patient in need thereof.
[0158] In yet another aspect, the invention provides a method for
the treatment or prophylaxis of traumatic brain injury comprising
administering a therapeutically effective amount of a PDE1
inhibitor of the invention, e.g., Formula I, I(i) or any of
1.1-1.23, in free or pharmaceutically acceptable salt form, to a
patient in need thereof. Traumatic brain injury (TBI) encompasses
primary injury as well as secondary injury, including both focal
and diffuse brain injuries. Secondary injuries are multiple,
parallel, interacting and interdependent cascades of biological
reactions arising from discrete subcellular processes (e.g.,
toxicity due to reactive oxygen species, overstimulation of
glutamate receptors, excessive influx of calcium and inflammatory
upregulation) which are caused or exacerbated by the inflammatory
response and progress after the initial (primary) injury.
[0159] The present invention also provides [0160] (i) a Compound of
the Invention, e.g., Formula I or any of any of 1.1-1.23 as
hereinbefore described in free, pharmaceutically acceptable salt
form for example for use in any method or in the treatment of any
disease or condition as hereinbefore set forth, [0161] (ii) the use
of a Compound of the Invention, e.g., Formula I, 1(i) or any of
1.1-1.23 as hereinbefore described, in free, pharmaceutically
acceptable salt form, (in the manufacture of a medicament) for
treating any disease or condition as hereinbefore set forth, [0162]
(iii) a pharmaceutical composition comprising a Compound of the
Invention, e.g., Formula I, I(i) or any of 1.1-1.23 as hereinbefore
described, in free, pharmaceutically acceptable salt form, in
combination or association with a pharmaceutically acceptable
diluent or carrier, and [0163] (iv) a pharmaceutical composition
comprising a Compound of the Invention, e.g., Formula I, I(i) or
any of 1.1-1.23 as hereinbefore described, in free,
pharmaceutically acceptable salt form, in combination or
association with a pharmaceutically acceptable diluent or carrier
for use in the treatment of any disease or condition as
hereinbefore set forth.
[0164] Therefore, the invention provides use of a Compound of the
Invention, e.g., Formula I, I(i) or any of 1.1-1.23 as hereinbefore
described, in free, pharmaceutically acceptable salt form, or a
Compound of the Invention in a pharmaceutical composition form, (in
the manufacture of a medicament) for the treatment or prophylactic
treatment of the fobllowing diseases: Parkinson's disease, restless
leg, tremors, dyskinesias, Huntington's disease, Alzheimer's
disease, and drug-induced movement disorders; depression, attention
deficit disorder, attention deficit hyperactivity disorder, bipolar
illness, anxiety, sleep disorder, narcolepsy, cognitive impairment,
e.g., cognitive impairment of schizophrenia, dementia, Tourette's
syndrome, autism, fragile X syndrome, psychostimulant withdrawal,
drug addiction, cerebrovascular disease, stroke, congestive heart
disease, hypertension, pulmonary hypertension, sexual dysfunction,
asthma, chronic obstructive pulmonary disease, and/or allergic
rhinitis, autoimmune disease, inflammatory diseases, female sexual
dysfunction, exercise amenorrhoea, anovulation, menopause,
menopausal symptoms, hypothyroidism, pre-menstrual syndrome,
premature labor, infertility, irregular menstrual cycles, abnormal
uterine bleeding, osteoporosis, multiple sclerosis, prostate
enlargement, prostate cancer, hypothyroidism, estrogen-induced
endometrial hyperplasia or carcinoma any disease or condition
characterized by low levels of cAMP and/or cGMP (or inhibition of
cAMP and/or cGMP signaling pathways) in cells expressing PDE1,
and/or by reduced dopamine D1 receptor signaling activity; and/or
any disease or condition that may be ameliorated by the enhancement
of progesterone signaling.
[0165] The invention also provides use of a Compound of the
Invention, in free or pharmaceutically acceptable salt form, for
the manufacture of a medicament for the treatment or prophylactic
treatment of: [0166] a) glaucoma or elevated intraocular pressure,
[0167] b) psychosis, for example, any conditions characterized by
psychotic symptoms such as hallucinations, paranoid or bizarre
delusions, or disorganized speech and thinking, e.g.,
schizophrenia, schizoaffective disorder, schizophreniform disorder,
psychotic disorder, delusional disorder, and mania, such as in
acute manic episodes and bipolar disorder, [0168] c) traumatic
brain injury.
[0169] The phrase "Compounds of the Invention" or "PDE 1 inhibitors
of the Invention" encompasses any and all of the compounds
disclosed herewith, e.g., a Compound of Formula I, I(i) or any of
1.1-1.23 as hereinbefore described, in free or salt form.
[0170] The words "treatment" and "treating" are to be understood
accordingly as embracing prophylaxis and treatment or amelioration
of symptoms of disease as well as treatment of the cause of the
disease. In one embodiment, the invention provides a method for the
treatment of the disease or disorder disclosed herein. In another
embodiment, the invention provides a method for the prophylaxis of
a disease or disorder as disclosed herein.
[0171] For methods of treatment, the word "effective amount" is
intended to encompass a therapeutically effective amount to treat a
specific disease or disorder.
[0172] The term "pulmonary hypertension" is intended to encompass
pulmonary arterial hypertension.
[0173] The term "patient" include human or non-human (i.e., animal)
patient. In particular embodiment, the invention encompasses both
human and nonhuman. In another embodiment, the invention
encompasses nonhuman. In other embodiment, the term encompasses
human.
[0174] The term "comprising" as used in this disclosure is intended
to be open-ended and does not exclude additional, unrecited
elements or method steps.
[0175] Compounds of the Invention are in particular useful for the
treatment of Parkinson's disease, narcolepsy and female sexual
dysfunction.
[0176] Compounds of the Invention, e.g., Formula I, I(i) or any of
1.1-1.23 as hereinbefore described, in free or pharmaceutically
acceptable salt form may be used as a sole therapeutic agent, but
may also be used in combination or for co-administration with other
active agents. For example, as Compounds of the Invention
potentiate the activity of D1 agonists, such as dopamine, they may
be simultaneously, sequentially, or contemporaneously administered
with conventional dopaminergic medications, such as levodopa and
levodopa adjuncts (carbidopa, COMT inhibitors, MAO-B inhibitors),
dopamine agonists, and anticholinergics, e.g., in the treatment of
a patient having Parkinson's disease. In addition, the novel PDE 1
inhibitors, e.g., as described herein, may also be administered in
combination with estrogen/estradiol/estriol and/or
progesterone/progestins to enhance the effectiveness of hormone
replacement therapy or treatment of estrogen-induced endometrial
hyperplasia or carcinoma.
[0177] Dosages employed in practicing the present invention will of
course vary depending, e.g. on the particular disease or condition
to be treated, the particular Compound of the Invention used, the
mode of administration, and the therapy desired. Compounds of the
Invention may be administered by any suitable route, including
orally, parenterally, transdermally, or by inhalation, but are
preferably administered orally. In general, satisfactory results,
e.g. for the treatment of diseases as hereinbefore set forth are
indicated to be obtained on oral administration at dosages of the
order from about 0.01 to 2.0 mg/kg. In larger mammals, for example
humans, an indicated daily dosage for oral administration will
accordingly be in the range of from about 0.75 to 150 mg,
conveniently administered once, or in divided doses 2 to 4 times,
daily or in sustained release form. Unit dosage forms for oral
administration thus for example may comprise from about 0.2 to 75
or 150 mg, e.g. from about 0.2 or 2.0 to 50, 75 or 100 mg of a
Compound of the Invention, together with a pharmaceutically
acceptable diluent or carrier therefor.
[0178] Pharmaceutical compositions comprising Compounds of the
Invention may be prepared using conventional diluents or excipients
and techniques known in the galenic art. Thus oral dosage forms may
include tablets, capsules, solutions, suspensions and the like.
EXAMPLES
[0179] The synthetic methods for various Compounds of the Present
Invention are illustrated below. The intermediates of the Compounds
of the Invention as well as other compounds of the Invention (e.g.,
compounds of formula 1.23) and their salts may be made using the
methods as similarly described below and/or by methods similar to
those generally described in the detailed description and by
methods known in the chemical art, particularly methods disclosed
in WO 2006/133261, WO 2009/075784 and WO 2010/065149, the contents
of each of which are incorporated by reference in their
entirety.
Example 1
3-(ethylthio)-2-(4-(S-fluoropyridin-2-yl)benzyl)-5,7,7-trimethyl-7,8-dihyd-
ro-2H-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00024##
[0181] A 2 mL microwave reaction vial is charged with
3-chloro-2-(4-(5-fluoropyridin-2-yl)benzyl)-5,7,7-trimethyl-7,8-dihydro-2-
H-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(SH)-one (160 mg, 0.36
mmol), K.sub.2CO.sub.3(150 mg, 1.1 mmol), excess ethanethiol (0.6
mL) and cyclopentanol (0.5 mL). The vial is sealed and heated with
stirring in a microwave reactor at 4 Barr, 150.degree. C. for 1
hour. LCMS indicates conversion of the starting material to
product. The reaction mixture is allowed to cool and was then
diluted with 100 mL water, and is extracted with dichloromethane
(3.times.30 mL). The combined organic layers are evaporated to
dryness, and the residue is dissolved in 1 mL dimethylformamide,
filtered, and then purified by HPLC to provide 126 mg of the
product as the formate salt (74% yield) with a purity of 95%. MS
(ESI) m/z 465.2 [M+H].sup.+.
Example 2
3-(ethylthio)-2-(4-(6-fluoropyridyl-2-yl)benzyl)-5,7,7-trimethyl-7,8-dihyd-
ro-2H-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00025##
[0183] A 2 mL microwave reaction vial is charged with
3-chloro-2-(4-(6-fluoropyridin-2-yl)benzyl)-5,7,7-trimethyl-7,8-dihydro-2-
H-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one (90 mg. 0.2
mmol), K.sub.2CO.sub.3 (100 mg, 0.73 mmol), excess ethanethiol (0.6
mL) and cyclopentanol (0.5 mL). The vial is sealed and heated with
stirring in a microwave reactor at 4 Barr, 150.degree. C. for 1
hour. LCMS indicates conversion of the starting material to
product. The reaction mixture is allowed to cool and is then
diluted with 100 mL water, and extracted with dichloromethane
(3.times.30 mL). The combined organic layers are evaporated to
dryness, and the residue is dissolved in I mL dimethylformamide,
filtered, and then purified by HPLC to provide 14 mg of the product
as the formate salt (13% yield) with a purity of >98%. MS (ESI)
m/z 465.2 [M+H].sup.+.
Example 3
2-(4-(6-fluoropyridin-2-yl)benzyl)-3-(isopropylthio)-5,7,7-trimethyl-7,8-d-
ihydro-2H-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00026##
[0185] A 2 mL microwave reaction vial was charged with
3-chloro-2-(4-(6-fluoropyridin-2-yl)benzyl)-5,7,7-trimethyl-7,8-dihydro-2-
H-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one s(88 mg. 0.2
mmol), K2CO3 (160 mg, 1.2 mmol), excess propane-2-thiol (0.5 mL)
and cyclopentanol (0.5 mL). The vial was sealed and heated with
stirring in a microwave reactor at 4 Barr, 150.degree. C. for 1
hour. LCMS indicates conversion of the starting material to
product. The reaction mixture is allowed to cool and is then
diluted with 100 mL water, and extracted with dichloromethane
(3.times.30 mL). The combined organic layers are evaporated to
dryness, and the residue is dissolved in I mL dimethylformamide,
filtered, and then purified by HPLC to provide 58 mg of the product
as the formate salt (55% yield) with a purity of 96.4%. MS (ESI)
m/z 479.3 [M+H].sup.+.
Example 3-A
(6aR,9a5s),6a,7,8,9,9a-hexahydro-5-methyl-3-(ethylthio)-2-(4-(6-fluoropyri-
din-2-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H-
)-one
##STR00027##
[0187] A 2 mL microwave reaction vial is charged with
6R,9aS)-5,6a,7,8,9,9a-hexahydro-3-chloro-5-methyl-2-(4-(6-fluoropyridin-2-
-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one
(45 mg. 0.1 mmol), K.sub.2CO.sub.3 (48 mg, 0.35 mmol), excess
ethanethiol (0.6 mL) and cyclopentanol (0.5 mL). The vial is sealed
and heated with stirring in a microwave reactor at 150.degree. C.
for 1 hour. LCMS indicates conversion of the starting material to
product. The reaction mixture is allowed to cool and is then
diluted with 100 mL water, and extracted with dichloromethane
(3.times.30 mL). The combined organic layers are evaporated to
dryness, and the residue is dissolved in I mL dimethylformamide,
filtered, and then purified by HPLC to provide 32 mg of the product
as the formate salt (61% yield) with a purity of >99%. MS (EST)
m/z 477.1 [M+H].sup.+.
Example 3-B
(6aR,9aS)-5,6a,7,8,9,9a-hexahydro-5-methyl-3-(isopropylthio)-2-(4-(6-fluor-
opyridin-2-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-
-4(2H)-one
##STR00028##
[0189] A 2 mL microwave reaction vial is charged with
6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-chloro-5-methyl-2-(4-(6-fluoropyridin--
2-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-on-
e (150 mg, 0.33 mmol), K.sub.2CO.sub.3 (270 mg, 1.95 mmol), excess
propane-2-thiol (0.5 mL) and cyclopentanol (0.5 mL). The vial is
sealed and heated with stirring in a microwave reactor at
150.degree. C. for 1 hour. LCMS indicates conversion of the
starting material to product. The reaction mixture is allowed to
cool and is then diluted with 100 mL water, and extracted with
dichloromethane (3.times.30 mL). The combined organic layers are
evaporated to dryness, and the residue is dissolved in I mL
dimethylformamide, filtered, and then purified by HPLC to provide
122 mg of the product as the formate salt (69% yield) with a purity
of 98%. MS (ESI) m/z 491.2 [M+H].sup.+.
Example 4
Measurement of PDE1B Inhibition In Vitro Using IMAP
Phosphodiesterase Assay Kit
[0190] Phosphodiesterase 1B (PDE1B) is a calcium/calmodulin
dependent phosphodiesterase enzyme that converts cyclic guanosine
monophosphate (cGMP) to 5'-guanosine monophosphate (5'-GMP). PDE1B
can also convert a modified cGMP substrate, such as the fluorescent
molecule cGMP-fluorescein, to the corresponding GMP-fluorescein.
The generation of GMP-fluorescein from cGMP-fluorescein can be
quantitated, using, for example, the IMAP (Molecular Devices,
Sunnyvale, Calif.) immobilized-metal affinity particle reagent.
[0191] Briefly, the IMAP reagent binds with high affinity to the
free 5'-phosphate that is found in GMP-fluorescein and not in
cGMP-fluorescein. The resulting GMP-fluorescein=IMAP complex is
large relative to cGMP-fluorescein. Small fluorophores that are
bound up in a large, slowly tumbling, complex can be distinguished
from unbound fluorophores, because the photons emitted as they
fluoresce retain the same polarity as the photons used to excite
the fluorescence.
[0192] In the phosphodiesterase assay, cGMP-fluorescein, which
cannot be bound to IMAP, and therefore retains little fluorescence
polarization, is converted to GMP-fluorescein, which, when bound to
IMAP, yields a large increase in fluorescence polarization
(.DELTA.mp). Inhibition of phosphodiesterase, therefore, is
detected as a decrease in .DELTA.mp.
[0193] Enzyme Assay
Materials: All chemicals are available from Sigma-Aldrich (St.
Louis, Mo.) except for IMAP reagents (reaction buffer, binding
buffer, FL-GMP and IMAP beads), which are available from Molecular
Devices (Sunnyvale, Calif.). Assay: The following phosphodiesterase
enzymes may be used: 3',5'-cyclic-nucleotide-specific bovine brain
phosphodiesterase (Sigma, St. Louis, Mo.) (predominantly PDE1B) and
recombinant full length human PDE1A and PDE1B (r-hPDE1A and
r-hPDE1B respectively) which may be produced e.g., in HEK or SF9
cells by one skilled in the art. The PDE1 enzyme is reconstituted
with 50% glycerol to 2.5 U/ml. One unit of enzyme will hydrolyze
1.0 .mu.mole of 3',5'-cAMP to 5'-AMP per min at pH 7.5 at
30.degree. C. One part enzyme is added to 1999 parts reaction
buffer (30 .mu.M CaCl.sub.2, 10 U/ml of calmodulin (Sigma P2277),
10 mM Tris-HCl pH 7.2, 10 mM MgCl.sub.2, 0.1% BSA, 0.05% NaN.sub.3)
to yield a final concentration of 1.25 mU/ml. 99 .mu.l of diluted
enzyme solution is added into each well in a flat bottom 96-well
polystyrene plate to which 1 .mu.l of test compound dissolved in
100% DMSO is added. The compounds are mixed and pre-incubated with
the enzyme for 10 min at room temperature.
[0194] The FL-GMP conversion reaction is initiated by combining 4
parts enzyme and inhibitor mix with 1 part substrate solution
(0.225 .mu.M) in a 384-well microtiter plate. The reaction is
incubated in dark at room temperature for 15 min. The reaction is
halted by addition of 60 .mu.l of binding reagent (1:400 dilution
of IMAP beads in binding buffer supplemented with 1:1800 dilution
of antifoam) to each well of the 384-well plate. The plate is
incubated at room temperature for 1 hour to allow IMAP binding to
proceed to completion, and then placed in an Envision multimode
microplate reader (PerkinElmer, Shelton, Conn.) to measure the
fluorescence polarization (.DELTA.mp).
[0195] A decrease in GMP concentration, measured as decreased
.DELTA.mp, is indicative of inhibition of PDE activity. IC.sub.5o
values are determined by measuring enzyme activity in the presence
of 8 to 16 concentrations of compound ranging from 0.0037 nM to
80,000 nM and then plotting drug concentration versus .DELTA.mP,
which allows IC.sub.50 values to be estimated using nonlinear
regression software (XLFit; IDBS, Cambridge, Mass.).
[0196] The Compounds of the Invention are tested in an assay as
described or similarly described herein for PDE1 inhibitory
activity. The exemplified compounds of the invention (e.g.
compounds of Examples 1-3, 3-A, 3-B or formula 1.22 and 1.23)
generally have IC.sub.50 values of less than 1 .mu.M, e.g., some
less than 10 nM, some less than or equal to 5 nM as shown
below.
TABLE-US-00001 Example r-hPDE1A - IC.sub.50 (nM) r-hPDE1B -
IC.sub.50 (.mu.M) 1 2.7 11 2 1 4 3 5 3 3-A 1.5 27 3-B 6 nd* *nd =
not determined
[0197] The compounds of the present invention have superior potent
PDE1 inhibitory activity compared to similar compounds in the art.
For example, the compound of Example 3-A is generally 122x more
potent against r-hPDE1A and 8x more potent against r-hPDE1B than,
e.g.,
(6aR,9aS)-5,6a,7,8,9,9a-hexahydro-5-methyl-3-(methylthio)-2-(4-(6-fluorop-
yridin-2-yl)benzyl)-cyclopent[4,5]imidazo[2-a]pyrazolo[4,3-e]pyrimidin-4(2-
H)-one, which compound has an IC.sub.50 of 183 nM and 225 nM
against r-hPDE1A and r-hPDE1B respectively.
Example 5
PDE1 Inhibitor Effect on Sexual Response in Female Rats
[0198] The effect of PDE1 inhibitors on Lordosis Response in female
rats may be measured as described in Mani, et al., Science (2000)
287: 1053. Ovariectomized and cannulated wild-type rats are primed
with 2 .mu.g estrogen followed 24 hours later by
intracerebroventricular (icy) injection of progesterone (2 zg),
PDE1 inhibitors of the present invention (0.1 mg, 1.0 mg or 2.5 mg)
or sesame oil vehicle (control). The rats may be tested for
lordosis response in the presence of male rats. Lordosis response
is quantified by the lordosis quotient (LQ=number of lordosis/10
mounts.times.100).
Example 6--Novel Object Recognition Assay
[0199] To measure the cognition-enhancing effects of the compounds
of the invention, the candidate compounds may be evaluated in a
Novel Object Recognition (NOR) assay. This assay protocol is
described in detail in Ennaceur et al., Behav. Brain Res. (1988)
31:47-59 and Prickaerts et al., Eur. J. Pharmacol. (1997)
337:125-136, the contents of each of which are incorporated by
reference in their entirety. In this protocol, the rats are
introduced to a chamber at time T1 and allowed to interrogate two
identical "familiar objects" for six minutes. Twenty four hours
later, they are re-introduced to this chamber, where one of the
familiar objects has been replaced with a novel object. The
"discrimination index", a measure of the time spent in close
proximity to the novel over the familiar object, may then be
measured. Since rodents will forget the original experience at T1
within 4 hours, this test with a 24h interval is a measure of
strong cognitive enhancement.
[0200] This assay protocol can be modified in order to evaluate
different phases of memory. There are three general phases of
memory, namely, acquisition, consolidation and retrieval. In this
modified protocol, the rats may be dosed with the candidate
compound two hours before T1 and tested 24h later, without
additional dosing. This is a test of the acquisition process. In
addition, administration at various other times after the T1 test
may be done to understand the compound's effectiveness in memory
consolidation and recall. Specifically, these dosing times
represent acquisition (T1-2h), early consolidation (T1+0.1 h), late
consolidation (T1+3h), and retrieval (T2-2h).
[0201] Using the protocol described above or similarly described
above, the compound of Example I is shown to be active versus
vehicle at p<0.01 at a dose of 0.3 mg/Kg PO when administering
to a rat 2 hours before T1.
Example 7--Haloperidol-Induced Induced Catalepsy Model
[0202] To evaluate the potential beneficial effects to motor
defects present in schizophrenics treated with typical and atypical
antipsychotic agents and in Parkinson's disease patients, the
compounds of the invention may be tested in a reversal of catalepsy
model in which motor freezing, or catalepsy, is induced by potent
dopamine D2 receptor antagonists such as haloperidol or
risperidone. The method uses the "bar grip test", in which the
front paws of the mouse are placed so as to grip a 3 mm-diameter,
suspended wooden bar. A "step down latency" is measured by
recording the time until the mouse removes its paws from the wooden
bar to the floor surface. Catalepsy is a freezing of the
musculature that prevents the mouse from moving off the bar.
Reduction in the catalepsy induced in this model will indicate that
the compound will have a beneficial effect both in schizophrenia
where extra-pyramidal side effects are frequent and in Parkinson's
disease.
[0203] A total of seventeen (17) eight week-old, male, C57BL/6 mice
(Jackson Laboratories) are used in a typical experiment testing the
effect of the compound of Example 1 or 2. Mice are divided into six
(6) groups (N=2 for vehicle group; N=3 mice/drug-treated group),
receiving the following treatments: Vehicle alone, haloperidol
alone (3 mg/kg PO), Compound of Example I or 2 alone (Mid-range
dose, PO), haloperidol+Compound of Example I or 2 (Low-range dose,
PO), haloperidol+Compound of Example I or 2 (Mid-range dose, PO),
or haloperidol+Compound of Example 1 or 2 (High-range dose, PO). A
catalepsy score is recorded for each mouse at 2, 3, 4 and 6 hours
after administration of drugs. The chamber used for measuring
catalepsy is comprised of a Plexiglas cage outfitted with a 3
mm-diameter wooden bar fixed horizontally 4 cm above the floor of
cage. For each test session, both forepaws of the mouse are placed
on the bar while the hind paws are on the Plexiglas floor. The
latency until the mouse steps both paws down from the bar to the
floor surface (i.e., step down latency) is recorded up to 120 sec.
If the mouse steps off immediately (less than 10 sec after
placement), another attempt is made up to a maximum of 10 attempts.
If none of the 10 attempts are beyond 10 sec, the longest duration
recorded is used as the catalepsy score. Otherwise, the initial
cataleptic duration (>10 sec) is recorded during the 120 sec
testing time. Mean step down latency is calculated for each
treatment group. The effect of the compound of Example 1 or 2 on
step down latency after haloperidol treatment is statistically
evaluated by comparing group differences by analysis of variance
(ANOVA, F.sub.5,16) followed by application of Newman-Keuls
post-hoc multiple comparison tests at each time point across all
doses tested.
[0204] By using the protocol described or similarly described in
this example, the experiment shows that the compounds of Example 1
and Example 2 are active in a catalepsy model with a minimal dose
of <0.1 mg/Kg.
* * * * *