U.S. patent application number 16/186272 was filed with the patent office on 2019-05-16 for compounds and methods.
This patent application is currently assigned to INTRA-CELLULAR THERAPIES, INC.. The applicant listed for this patent is INTRA-CELLULAR THERAPIES, INC.. Invention is credited to Peng LI, Lawrence WENNOGLE, Jun ZHAO, Hailin ZHENG.
Application Number | 20190144460 16/186272 |
Document ID | / |
Family ID | 55533880 |
Filed Date | 2019-05-16 |
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United States Patent
Application |
20190144460 |
Kind Code |
A1 |
LI; Peng ; et al. |
May 16, 2019 |
COMPOUNDS AND METHODS
Abstract
The subject matter generally relates to compounds and methods of
treatment and/or prophylaxis of CNS diseases, disorders, and/or
injuries. In one aspect, the subject matter relates to inhibitors
of phosphodiesterase 1 (PDE1) as neuroprotective agents and/or
neural regenerative agents. In a further aspect, the subject matter
relates to individuals that are at risk for the development of CNS
disease or disorder.
Inventors: |
LI; Peng; (New Milford,
NJ) ; ZHENG; Hailin; (Teaneck, NJ) ; ZHAO;
Jun; (Highland Park, NJ) ; WENNOGLE; Lawrence;
(Hillsborough, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTRA-CELLULAR THERAPIES, INC. |
New York |
NY |
US |
|
|
Assignee: |
INTRA-CELLULAR THERAPIES,
INC.
New York
NY
|
Family ID: |
55533880 |
Appl. No.: |
16/186272 |
Filed: |
November 9, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15512005 |
Mar 16, 2017 |
10150774 |
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PCT/US15/50814 |
Sep 17, 2015 |
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16186272 |
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62052283 |
Sep 18, 2014 |
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62051735 |
Sep 17, 2014 |
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Current U.S.
Class: |
514/267 ;
544/251 |
Current CPC
Class: |
A61P 29/00 20180101;
A61P 27/06 20180101; A61P 25/28 20180101; A61P 3/10 20180101; A61P
25/00 20180101; C07D 487/14 20130101; A61P 27/02 20180101; A61P
25/14 20180101; A61P 25/16 20180101; A61P 3/00 20180101; A61P 21/00
20180101; A61P 25/08 20180101 |
International
Class: |
C07D 487/14 20060101
C07D487/14 |
Claims
1-16. (canceled)
17. A method for the prophylaxis and/or treatment of a CNS disease,
disorder, and/or injury, wherein the method comprises the
administration of an effective amount of a PDE1 inhibitor to a
subject, wherein the administration of the PDE1 inhibitor modulates
the subject's level of intracellular cAMP, wherein the PDE 1
inhibitor is a compound according to Formula V ##STR00030## wherein
(i) R.sub.1 is C.sub.1-4 alkyl (e.g., methyl); (ii) R.sub.4 is H
and R.sub.2 and R.sub.3 are, independently, H or C.sub.1-4 alkyl
(e.g., R.sub.2 and R.sub.3 are both methyl, or R.sub.2 is H and
R.sub.3 is isopropyl); (iii) R.sub.5 is attached to one of the
nitrogens on the pyrazolo portion of Formula V and is a moiety of
Formula A ##STR00031## wherein X, Y and Z are C, and R.sub.8,
R.sub.9, R.sub.11 and R.sub.12 are H, and R.sub.10 is halogen, or
heteroaryl optionally substituted with halogen, alkyl, haloalkyl,
hydroxy or carboxy (e.g., pyridyl or 2-halopyridyl, (for example,
pyrid-2-yl, 5-fluoropyrid-2-yl or 6-fluoropyrid-2-yl)); and (iv)
R.sub.6 is H, C.sub.1-4alkyl, arylamino optionally substituted with
C.sub.1-4alkyl or halogen (e.g., phenylamino or
4-fluorophenylamino); and (v) n=0; in free or pharmaceutically
acceptable salt form.
18. A method according to claim 17, wherein the CNS disease,
disorder, or injury is a spinal cord injury.
19. The method according to claim 17, wherein the CNS disease,
disorder, or injury relates to motor neuron trauma.
20. The method according to claim 17, wherein the CNS disease,
disorder, or injury is selected from the group consisting of:
neurological traumas and injuries, surgery related trauma and/or
injury, retinal injury and trauma, injury related to epilepsy,
spinal cord injury, brain injury, brain surgery, trauma related
brain injury, trauma related to spinal cord injury, brain injury
related to cancer treatment, spinal cord injury related to cancer
treatment, brain injury related to infection, brain injury related
to inflammation, spinal cord injury related to infection, spinal
cord injury related to inflammation, brain injury related to
environmental toxins, and spinal cord injury related to
environmental toxins.
21. The method according to claim 17, wherein the CNS disease,
disorder, or injury is a neurodegenerative disorder.
22. The method according to claim 21, wherein the neurodegenerative
disease, disorder, or injury is selected from the group consisting
of: Alzheimer's disease, Multiple Sclerosis, Glaucoma,
Frontotemporal dementia, Dementia with Lewy bodies, Corticobasal
degeneration, Progressive supranuclear palsy, Prion disorders,
Huntington's disease, Multiple system atrophy, Parkinson's disease,
Amyotrophic lateral sclerosis, Hereditary spastic paraparesis,
Spinocerebellar atrophies, Friedreich's ataxia, Amyloidoses,
Metabolic (diabetes) related disorders, Toxin related disorders,
chronic CNS inflammation, and Charcot Marie Tooth disease.
23. (canceled)
24. A method according to claim 17, wherein the PDE1 inhibitor is
administered to a patient that is shown to have elevated
intracellular calcium levels compared to a control subject (e.g.,
reference standard).
25. A method of prophylaxis of the development of a CNS disease or
disorder in a subject that is at risk for developing a CNS disease
or disorder, wherein the method comprises: 1.) Obtaining a CNS
sample from the subject; 2.) Measuring the levels of intracellular
calcium from the sample; 3.) Comparing the levels of intracellular
calcium in the biological sample to a reference standard; 4.)
Determining whether a patient is at risk for developing a CNS
disease or disorder based upon the level of intracellular calcium
compared to the reference standard; 5.) Administering a PDE1
inhibitor to a subject based upon the subject's levels of
intracellular calcium put them at risk for the development of a CNS
disease or disorder (e.g., administration of a PDE1 inhibitor to a
subject because they have elevated intracellular calcium levels
compared to the reference standard), wherein the PDE1 inhibitor is
a compound according to claim 17.
26. A method according to claim 17, wherein R.sub.1 is methyl.
27. A method according to claim 17, wherein R.sub.2 and R.sub.3 are
C.sub.1-4 alkyl.
28. A method according to claim 17, wherein R.sub.2 and R.sub.3 are
both methyl.
29. A method according to claim 17, wherein R.sub.10 is heteroaryl
optionally substituted with halogen.
30. A method according to claim 17, wherein R.sub.10 is
pyrid-2-yl.
31. A method according to claim 17, wherein R.sub.10 is
5-fluoro-pyrid-2-yl.
32. A method according to claim 17, wherein R.sub.10 is
6-fluoro-pyrid-2-yl.
33. A method according to claim 17, wherein R.sub.6 is C.sub.1-4
alkyl.
34. A method according to claim 17, wherein R.sub.6 is ethyl.
35. A method according to claim 17, wherein R.sub.6 is propyl.
36. A method according to claim 17, wherein R.sub.6 is arylamino
optionally substituted with C.sub.1-4alkyl or halogen.
37. A method according to claim 17, wherein R.sub.6 is
4-fluorophenylamino.
38. A method according to claim 17, wherein the compound is
selected from: ##STR00032## ##STR00033## in free or
pharmaceutically acceptable salt form.
39. A method according to claim 17, wherein the compound is
selected from: ##STR00034## in free or pharmaceutically acceptable
salt form.
40. A method according to claim 17, wherein R.sub.10 is halogen and
R.sub.6 is arylamino substituted with C.sub.1-4 alkyl or
halogen.
41. A method according to claim 17, wherein R10 is unsubstituted
heteroaryl and R6 is arylamino substituted with C1-4 alkyl or
halogen.
42. A method according to claim 17, wherein R10 is heteroaryl
substituted with halogen, alkyl, haloalkyl, hydroxy.
43. A method according to claim 42, wherein R.sub.6 is C.sub.1-4
alkyl.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This International Application claims the benefit of earlier
filed United States provisional applications U.S. 62/051,735, filed
Sep. 17, 2014, and U.S. 62/052,283, filed Sep. 18, 2014, each of
which is incorporated herein by reference in their entireties.
FIELD OF THE INVENTION
[0002] The field generally relates to compounds and methods of
treatment and/or prophylaxis of central nervous system (CNS)
diseases, disorders, and/or injuries. In one aspect, the field
relates to inhibitors of phosphodiesterase 1 (PDE1) as
neuroprotective agents and/or neural regenerative agents. In a
further aspect, the field relates to preventing the development of
a CNS disease or disorder in an individual at risk for the
development of a CNS disease or disorder.
BACKGROUND OF THE INVENTION
[0003] Cyclic nucleotide phosphodiesterases (PDEs) downregulate
intracellular cAMP and cGMP signaling by hydrolyzing these cyclic
nucleotides to their respective 5'-monophosphates (5'AMP and
5'GMP). Eleven families of phosphodiesterases have been identified,
but only PDEs in Family I, the Ca.sup.2+/calmodulin-dependent
phosphodiesterases (CaM-PDEs), which are activated by
Ca.sup.2+-calmodulin, have been shown to mediate 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 central nervous system tissue. PDE1A is expressed
throughout the brain with higher levels of expression in the CA1 to
CA3 layers of the hippocampus and cerebellum and at a lower level
in the striatum. PDE1A is also expressed in the lung and heart.
PDE1B is predominately expressed in the striatum, dentate gyrus,
olfactory tract and cerebellum, and its expression correlates with
brain regions having high levels of dopaminergic innervation.
Although PDE1B is primarily expressed in the central nervous
system, it is also detected in the heart, is present in neutrophils
and has been shown to be involved in inflammatory responses of this
cell. PDE1C is expressed in olfactory epithelium, cerebellar
granule cells, striatum, heart, and vascular smooth muscle.
[0004] 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 activates 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, adenosine (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 1 (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 neurodegenerative 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] Additionally, neurogenesis is a vital process in the brains
of animals and humans, whereby new nerve cells are continuously
generated throughout the life span of the organism. The newly
formed cells are able to differentiate into functional cells of the
central nervous system and integrate into existing neural circuits
in the brain. Neurogenesis is known to persist throughout adulthood
in two regions of the mammalian brain: the subventricular zone
(SVZ) of the lateral ventricles and the dentate gyrus of the
hippocampus. In these regions, multipotent neural progenitor cells
(NPCs) continue to divide and give rise to new functional neurons
and glial cells. It has been shown that a variety of factors can
stimulate adult hippocampal neurogenesis, e.g., adrenalectomy,
voluntary exercise, enriched environment, hippocampus dependent
learning and antidepressants. Other factors, such as adrenal
hormones, stress, age and drugs of abuse negatively influence
neurogenesis.
[0008] While the importance of neurogenesis cannot be overstated,
the failure of axons to regenerate after spinal cord injury still
remains one of the greatest challenges facing both medicine and
neuroscience. Unlike the myelinated axons of the peripheral nervous
system, myelinated axons of the central nervous system do not
regenerate after being severed. An important development, however,
has been the identification of inhibitory proteins in the myelin
sheaths that surround CNS axons. Certain bioactive molecules appear
to inhibit neurite outgrowth, leading to failure of CNS neuron
regeneration. Myelin contains a number of proteins that have been
shown to inhibit neurite process outgrowth. NogoA, a member of the
reticulon family, was the first protein identified as a neurite
outgrowth inhibitor. It is expressed by oligodendrocytes and some
neurons, and can be found both intracellularly and on the cell
surface (particularly on the myelin sheaths of axons). Other
proteins that can contribute to inhibition of axon regeneration
include myelin-associated glycoprotein (MAG),
oligodendrocyte-myelin glycoprotein (OMgp) and the proteoglycan
versican.
[0009] Thus, it appears that the CNS environment limits axonal
regeneration after injury. Indeed, CNS myelin has been identified
as a major factor contributing to regenerative failure. Evidence
exists that shows that CNS proteins present in the myelin sheath
inhibit axonal growth and regeneration.
[0010] Various strategies have been proposed for overcoming the
inhibition of axonal regeneration. One strategy that has been
effective has been to elevate the levels of intracellular cAMP.
This can be accomplished in several ways, such as: a peripheral
conditioning lesion, administration of cAMP analogues, priming with
neurotrophins or treatment with the phosphodiesterase inhibitor
rolipram (PDE4 inhibitor). The effects of cAMP may be transcription
dependent, and cAMP-mediated activation of CREB may lead to
upregulation and expression of genes such as arginase I and
interleukin-6. The products of these genes are believed to promote
axonal regeneration, which raises the possibility that other
cAMP-regulated genes could yield additional agents that would be
beneficial in the treatment of spinal cord injury. However, with
regard to increasing the expression of IL-6, one significant
disadvantage to this mechanism of action may be that IL-6 is a
potentially harmful pro-inflammatory cytokine, meaning, it is
possible that high levels of IL-6 could actually exacerbate the
inflammation that occurs after spinal cord injury which could then
lead to increase in cell death. Indeed, a factor supporting this
concern is that IL-6 transgenic mice have been observed to have
extensive astrogliosis, neurodegeneration, and breakdown of the
blood brain barrier.
SUMMARY OF THE INVENTION
[0011] The invention provides for a compound of Formula V:
##STR00001##
wherein [0012] (i) R.sub.1 is C.sub.1-4 alkyl (e.g., methyl);
[0013] (ii) R.sub.4 is H and R.sub.2 and R.sub.3 are,
independently, H or C.sub.1-4 alkyl (e.g., R.sub.2 and R.sub.3 are
both methyl, or R.sub.2 is H and R.sub.3 is isopropyl); [0014]
(iii) R.sub.5 is attached to one of the nitrogens on the pyrazolo
portion of Formula V and is a moiety of Formula A
[0014] ##STR00002## [0015] wherein X, Y and Z are C, and R.sub.8,
R.sub.9, R.sup.11 and R.sub.12 are H, and R.sub.10 is halogen (e.g.
chloro), or heteroaryl optionally substituted with halogen, alkyl,
haloalkyl, hydroxy or carboxy (e.g., pyridyl or 2-halopyridyl, (for
example, pyrid-2-yl, 5-fluoropyrid-2-yl or 6-fluoropyrid-2-yl));
and [0016] (iv) R.sub.6 is H, C.sub.1-4alkyl (e.g. methyl, ethyl or
propyl), arylamino optionally substituted with C.sub.1-4alkyl or
halogen (e.g., phenylamino or 4-fluorophenylamino), or
thioC.sub.1-4alkyl (e.g., thioethyl); and [0017] (v) n=0; in free,
salt or prodrug form, including its enantiomers, diastereoisomers
and racemates.
[0018] In a further aspect, the invention contemplates that the
PDE1 inhibitors (e.g., Formula V) are compounds of Formula V
according to any of the following formulae: [0019] 1.1 The compound
of Formula V, wherein R.sub.1 is methyl; [0020] 1.2 The compound of
Formula V or 1.1, wherein R.sub.2 and R.sub.3 are C.sub.1-4 alkyl;
[0021] 1.3 The compound of Formula V or any of 1.1-1.2, wherein
R.sub.2 and R.sub.3 are both methyl; [0022] 1.4 The compound of
Formula V or any of 1.1-1.3, wherein R.sub.10 is heteroaryl
optionally substituted with halogen; [0023] 1.5 The compound of
Formula V or any of 1.1-1.4, wherein R.sub.10 is pyrid-2-yl; [0024]
1.6 The compound of Formula V or any of 1.1-1.4, wherein R.sub.10
is 5-fluoro-pyrid-2-yl; [0025] 1.7 The compound of Formula V or any
of 1.1-1.4, wherein R.sub.10 is 6-fluoro-pyrid-2-yl; [0026] 1.8 The
compound of Formula V or any of 1.1-1.7, wherein R.sub.6 is
C.sub.1-4alkyl; [0027] 1.9 The compound of Formula V or any of
1.1-1.8, wherein R.sub.6 is ethyl; [0028] 1.10 The compound of
Formula V or any of 1.1-1.8, wherein R.sub.6 is propyl; [0029] 1.11
The compound of Formula V or any of 1.1-1.7, wherein R.sub.6 is
arylamino optionally substituted with C.sub.1-4alkyl or halogen;
[0030] 1.12 The compound of Formula V or any of 1.1-1.7, wherein
R.sub.6 is 4-fluorophenylamino; [0031] 1.13 Any of the preceding
formulae wherein the compound is selected from the group
consisting
##STR00003## ##STR00004##
[0031] in free, salt or prodrug form, including its enantiomers,
diastereoisomers and racemates. [0032] 1.14 Any of the preceding
formulae wherein the compound is selected from a group consisting
of:
##STR00005##
[0032] in free, salt or prodrug form, including its enantiomers,
diastereoisomers and racemates.
[0033] In one aspect, selective PDE1 inhibitors of the any of the
preceding formulae (e.g., Formula V or 1.1-1.14) are compounds that
inhibit phosphodiesterase-mediated (e.g., PDE1-mediated, especially
PDE1A or PDE1C-mediated) hydrolysis of cGMP, e.g., the preferred
compounds have an IC50 of less than 1 M, preferably less than 500
nM, and more preferably less than 50 nM, in an immobilized-metal
affinity particle reagent PDE assay, in free or salt form.
[0034] It is one advantage of the present invention that a PDE1
inhibitor (e.g., a compound of any of Formula V or 1.1-1.14) may
act as a neuroprotective agent and/or neuroregenerative agent. In
the event of a CNS injury (e.g., spinal cord injury), disease, or
disorder, the compounds and methods disclosed herein may be
employed to aid or enhance neurite outgrowth and axonal
regeneration even in the presence of inhibitors of axonal
regeneration.
[0035] Without being bound by any particular theory, it is believed
that at least one advantage of the present invention is that the
administration of a PDE1 inhibitor (e.g., any compound of Formula V
or 1.1-1.14) may act to increase levels of intracellular cAMP and
initiate the transcription of genes that are necessary for
overcoming the inhibition of axonal regeneration and promoting
neurite outgrowth and/or axonal regeneration in the case of a CNS
disease, disorder, or injury. For instance, increased intracellular
cAMP, such as would result from PDE1 inhibition, would lead to
increased activity of cAMP-dependent proteins, such as protein
kinase C (PKC).
[0036] Furthermore, it is believed that the administration of a
PDE1 inhibitor (e.g., a compound of any of Formula V or 1.1-1.14)
may elevate the intracellular levels of both cAMP and cGMP. Without
being bound by theory, this rise in both cAMP and cGMP may serve to
counterbalance the potentially detrimental effects that may be
associated with chronically elevated levels of intracellular
calcium. It has been observed that elevated levels of intracellular
calcium may be associated with the development of various
degenerative diseases. For instance, one possible explanation is
that elevated levels of intracellular calcium (e.g., chronically
elevated levels of intracellular calcium) leads to the activation
of PDE1, which then stimulates cAMP hydrolysis. The decreased
concentration of cAMP would then deactivate cAMP-dependent proteins
such as protein kinase C (PKC).
[0037] However, without being bound by any theory, it is believed
that another potential benefit of the administration of a PDE1
inhibitor (e.g., a compound of any of Formula V or 1.1-1.14) is an
increase in intracellular cGMP. This increase in intracellular cGMP
may lead to an increase in the activity of PKG, preventing a
further rise in intracellular calcium levels. Thus, without being
bound by any theory, the administration of a PDE1 inhibitor (e.g.,
a compound of any of Formula V or 1.1-1.14) could have the dual
benefit of, for example, playing a beneficial role in axonal
regeneration (and/or neuroprotection) while simultaneously
decreasing the deleterious effects that may be associated with
elevated intracellular calcium levels.
[0038] In one embodiment the invention comprises compositions and
methods to treat or prevent a CNS disease, disorder, or injury
(e.g., spinal cord injury, e.g., spinal muscular atrophy, e.g.,
motor neuron injury), wherein the method comprises administration
of an effective amount of a PDE1 inhibitor (e.g., a compound of any
of Formula V or 1.1-1.14) to modulate intracellular levels of cAMP
and/or cGMP. In one embodiment, this increase in intracellular cAMP
is neuroprotective and/or aids in the increase or stimulation of
neurogenesis (e.g., the PDE1 inhibitor increases neurite outgrowth
and/or axonal regeneration).
[0039] In still a further embodiment, the invention comprises
compositions and methods to treat or prevent injuries to the
peripheral nervous system (PNS) wherein the method comprises
administration of a PDE1 inhibitor to increase intracellular levels
of cAMP and/or cGMP which, either directly or indirectly, increases
nerve regeneration and/or is protective against further nerve
damage.
[0040] In one embodiment the invention comprises compositions and
methods to prevent a CNS disease or disorder in a subject that is
at risk for developing said disease or disorder, wherein the method
comprises:
[0041] 1.) Obtaining a CNS sample from the subject;
[0042] 2.) Measuring the levels of intracellular calcium from the
sample;
[0043] 3.) Comparing the levels of intracellular calcium in the
biological sample to a reference standard;
[0044] 4.) Determining whether a patient is at risk for developing
a CNS disease or disorder based upon the level of intracellular
calcium compared to the reference standard;
[0045] 5.) Administering a PDE1 inhibitor (e.g., a compound of any
of Formula V or 1.1-1.14) to a subject based upon the subject's
levels of intracellular calcium (e.g., administration of a PDE1
inhibitor to a subject because they have elevated intracellular
calcium levels compared to the reference standard).
[0046] If not otherwise specified or clear from context, the
following terms herein have the following meanings: [0047] (a)
"Alkyl" as used herein is a saturated or unsaturated hydrocarbon
moiety, preferably saturated, preferably having one to six 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. [0048] (b) "Cycloalkyl" as used
herein is a saturated or unsaturated nonaromatic hydrocarbon
moiety, preferably saturated, preferably comprising three to nine
carbon atoms, at least some of which form a nonaromatic mono- or
bicyclic, or bridged cyclic structure, and which may be optionally
substituted, e.g., with halogen (e.g., chloro or fluoro), hydroxy,
or carboxy. Where the cycloalkyl optionally contains one or more
atoms selected from N and O and/or S, said cycloalkyl may also be a
heterocycloalkyl. [0049] (c) "Heterocycloalkyl" is, unless
otherwise indicated, a saturated or unsaturated nonaromatic
hydrocarbon moiety, preferably saturated, preferably comprising
three to nine carbon atoms, at least some of which form a
nonaromatic mono- or bicyclic, or bridged cyclic structure, wherein
at least one carbon atom is replaced with N, O or S, which
heterocycloalkyl may be optionally substituted, e.g., with halogen
(e.g., chloro or fluoro), hydroxy, or carboxy. [0050] (d) "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). [0051] (e)
"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. [0052] (f) It is intended that wherein the
substituents end in "ene", for example, alkylene, phenylene or
arylalkylene, said substitutents are intended to bridge or be
connected to two other substituents. Therefore, methylene is
intended to be --CH.sub.2-- and phenylene intended to be
--C.sub.6H.sub.4-- and arylalkylene is intended to be, for example,
--C.sub.6H.sub.4--CH.sub.2-- or --CH.sub.2--C.sub.6H.sub.4--.
[0053] 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
[0054] Compounds of the Invention, encompassing any of the
compounds disclosed herein, 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.
[0055] Compounds of the Invention may in some cases also exist in
prodrug form. A prodrug form is a 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 carboxylic 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 alcohol HO--C.sub.1-4alkyl. As will be
appreciated the term thus embraces conventional pharmaceutical
prodrug forms.
[0056] In another embodiment, the invention further provides a
pharmaceutical composition comprising a Compound of the Invention,
in free or pharmaceutically acceptable salt form, in admixture with
a pharmaceutically acceptable carrier.
Methods of Making Compounds of the Invention
[0057] 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 are 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.
[0058] Various starting materials and/or Compounds of the Invention
may be prepared using methods described in US 2008-0188492 A1, US
2010-0173878 A1, US 2010-0273754 A1, US 2010-0273753 A1, WO
2010/065153, WO 2010/065151, WO 2010/065151, WO 2010/065149, WO
2010/065147, WO 2010/065152, WO 2011/153129, WO 2011/133224, WO
2011/153135, WO 2011/153136, WO 2011/153138, US 2014/0194396,
PCT/US14/30412, and each reference is herein incorporated by
reference in its entirety.
[0059] 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.
[0060] It is also intended that the Compounds of the Invention
encompass their stable and unstable isotopes. That is, the
Compounds of the Invention embrace the replacement or enrichment of
any atom, or more than one atom, of the structure by any stable or
unstable isotopic variant of that atom. Isotopes are atoms of the
same element that contain varying numbers of neutrons. An isotopic
variant is any isotope of any element other than its naturally most
abundant isotope. An isotopic variant will contain one or more
additional, or one or more fewer, neutrons compared to the most
naturally abundant nuclide of the same element. Isotopes may either
be stable (non-radioactive) or unstable (radioactive). For example,
the most naturally abundant nuclide of carbon is .sup.12C, and one
known stable isotope of carbon is .sup.13C. Isotopes of an element
generally share the same characteristic electronic and chemical
properties. 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 one or more
atomic positions of the Compounds of the Invention may be replaced
with (or enriched in) deuterium. Examples of known stable isotopes
include, but are not limited to, deuterium (.sup.2H), .sup.13C,
.sup.15N, and .sup.18O. Examples of known unstable isotopes include
.sup.3H, .sup.123I, .sup.131I, .sup.125I, .sup.11C, .sup.18F.
Unstable isotopes may be useful for radio-imaging and/or
pharmacokinetic studies of the compounds of the invention. One or
more atomic positions in a Compound of the Invention may be
replaced with or enriched in any known isotopic variant. Natural
sources of chemicals and reagents are not generally isotopically
pure, so that Compounds of the Invention made by traditional
chemical methods will generally have some normal, natural variation
in isotopic abundance. For example, the natural abundance of the
element carbon consists approximately of 98.93% .sup.12C and 1.07%
.sup.13C. Therefore, Compounds of the Invention made by traditional
chemical means will typically consist of about 98.93% .sup.12C and
1.07% .sup.13C at each carbon atom of the structure. Enrichment
refers to the presence of more than the natural abundance of a
minor isotope in a chemical structure. Thus, for example, a
Compound of the Invention may be enriched for the presence of
.sup.13C at one or more carbon atom positions. As used herein,
"replacement" refers to enrichment of an isotopic variant of
greater than about 95%.
[0061] Melting points are uncorrected and "dec" indicates
decomposition. Temperatures 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 presented using delta values of the
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
[0062] BOC=tert-butoxycarbonyl
[0063]
BOP=Benzotriazole-1-yl-oxy-tris(dimethylamino)phosphonium
[0064] hexafluorophosphate
[0065] BuLi=n-butyllithium
[0066] Bu.sup.tOH=tert-butyl alcohol,
[0067] CAN=ammonium cerium (IV) nitrate,
[0068] DBU=1,8-diazabicyclo[5.4.0]undec-7-ene,
[0069] DIPEA=diisopropylethylamine,
[0070] DMF=N,N-dimethylforamide,
[0071] DMSO=dimethyl sulfoxide,
[0072] Et.sub.2O=diethyl ether,
[0073] EtOAc=ethyl acetate,
[0074] equiv.=equivalent(s),
[0075] h=hour(s),
[0076] HPLC=high performance liquid chromatography,
[0077] LDA=lithium diisopropylamide
[0078] MeOH=methanol,
[0079] NBS=N-bromosuccinimide
[0080] NCS=N-chlorosuccinimide
[0081] NaHCO.sub.3=sodium bicarbonate,
[0082] NH.sub.4OH=ammonium hydroxide,
[0083]
Pd.sub.2(dba).sub.3=tris[dibenzylideneacetone]dipalladium(0)
[0084] PMB=p-methoxybenzyl,
[0085] POCl.sub.3=phosphorous oxychloride,
[0086] SOCl.sub.2=thionyl chloride,
[0087] TFA=trifluoroacetic acid,
[0088] TFMSA=trifluoromethanesulfonic acid
[0089] THF=tetrahedrofuran.
[0090] The synthetic methods useful in this invention are
illustrated below. The definitions for the R groups are as set
forth above for any of Formulae V or 1.1-1.14, unless otherwise
indicated.
[0091] Intermediate compounds of formula IIb can be prepared by
reacting a compound of formula IIa with malonic acid and acetic
anhydride in acetic acid, optionally with heating (e.g., to about
90.degree. C. for about 3 hours):
##STR00006##
wherein R.sub.1 is C.sub.1-4 alkyl, e.g., methyl.
[0092] Intermediates of formula IIc can be prepared by reacting a
compound of formula IIb with a chlorinating compound such as
POCl.sub.3, optionally with small amounts of water and/or heating
(e.g., heating to about 80.degree. C. for about 4 hours):
##STR00007##
[0093] Intermediates of formula IId may be prepared by reacting
compounds of formula IIc with, for example, a reagent P.sup.1-L in
a solvent such as DMF, with a base such as potassium carbonate,
sodium bicarbonate, cesium carbonate, sodium hydroxide,
triethylamine, diisopropylethylamine or the like, at room
temperature or with heating:
##STR00008##
wherein P.sup.1 is a protective group (e.g., PMB or BOC); and L is
a leaving group such as a halogen, mesylate, or tosylate.
Preferably, P.sup.1 is PMB and the base is potassium carbonate.
[0094] Intermediates of formula IIe may be prepared by reacting
compounds of formula IId with hydrazine or hydrazine hydrate in a
solvent such as methanol, preferably with heating (e.g. reflux for
about 4 hours):
##STR00009##
[0095] Intermediates of formula IVa may be prepared by reacting
compound of formula IIe with POCl.sub.3 and DMF:
##STR00010##
[0096] Intermediates of formula IVb may be prepared by reacting a
compound of formula IVa with a reagent of formula F.sup.1--X in a
solvent such as DMF with a base such as potassium carbonate at room
temperature:
##STR00011##
wherein F.sup.1 is a protecting group (e.g., a substituted benzyl
group, such as 4-bromobenzyl), and X is a halogen (e.g., Br).
[0097] Intermediates of formula IVc may be prepared from compounds
of formula IVb by removing the protective group P.sup.1 using an
appropriate method. For example, if P.sup.1 is a PMB group, then it
can be removed with TFA/TFMSA at ambient or elevated temperature,
whereas if P1 is BOC, then it can be removed using an acid such as
TFA or aqueous hydrochloric acid:
##STR00012##
[0098] Intermediates of formula IVd can be prepared by reacting a
compound of formula IVc with a chlorinating compound such as
POCl.sub.3, optionally with heating (e.g., reflux for 2 days or
more, or microwave irradiation at 150-200.degree. C. for 5-10
minutes in a sealed vial):
##STR00013##
[0099] Intermediates of formula IVe can be prepared by reacting a
compound of formula IVd with an amino alcohol under basic condition
in a solvent such as DMF, optionally with heating:
##STR00014##
wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are as defined
previously for any of Formulae V or 1.1-1.14.
[0100] Alternatively, intermediates IVe can be prepared directly
from compounds of formula IVc by reacting with an amino alcohol and
a coupling reagent such as BOP in the presence of a base such as
DBU:
##STR00015##
wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are as defined
previously for any of Formulae V or 1.1-1.14.
[0101] Intermediates of formula IVf may be prepared by reacting a
compound of formula IVe with a dehydrating/halogenating agent such
as SOCl.sub.2 in a solvent such as dichloromethane at room
temperature or with heating at 35.degree. C.:
##STR00016##
[0102] Intermediates of formula IVg may be prepared by reacting a
compound of formula IVf with, catalysts such as a copper salt and
2,2,6,6-tetramethylheptane-3,5-dione and a base such as cesium
carbonate in a solvent such as NMP with heating:
##STR00017##
wherein, F.sup.2 is a diaryl ether.
[0103] Intermediates of formula IVh may be prepared by reacting a
compound of formula IVg with an acidici system, such as TFA and
TFMSA in a solvent such as dichloromethane, at room
temperature:
##STR00018##
[0104] Intermediates of formula IVi may be prepared by reacting a
compound of formula IVh with a reagent of formula
R.sub.5--(CH.sub.2).sub.n-L in the presence of a base such as
potassium carbonate, in a solvent such as DMF at room
temperature:
##STR00019##
wherein n is 0, and R.sub.5 is a moiety of Formula A, as defined
previously for any of Formulae V or 1.1-1.14, and L is a leaving
group such as a halogen (e.g., Br).
[0105] Intermediates of formula IVj, wherein X is halogen (e.g.,
Cl), may be prepared by reacting compounds of formula IVi with a
halogenating agent (e.g. NCS or NBS) and a base such as LiHMDS in a
solvent such as THF at low temperature:
##STR00020##
[0106] Compounds of the Invention, may then be prepared from
compounds of Formula IVj by methods known to those skilled in the
art. For example, by displacement of the halogen X with an
arylamine or an alkylmercaptan.
Methods of Using Compounds of the Invention
[0107] The invention further provides Method I, wherein Method I
comprises the prophylaxis and/or treatment of diseases, disorders,
and injuries of the central nervous system, wherein the method
comprises the administration of an effective amount of a PDE1
inhibitor (e.g., any compound of Formula V or 1.1-1.14) to modulate
the level of intracellular cAMP.
[0108] For example, Method I also includes: [0109] 1.1. Method I,
wherein the administration of the PDE1 inhibitor enhances the
axonal growth or regeneration, and/or slows or reverses the loss of
such cells in a neurodegenerative condition. [0110] 1.2. Any of
preceding Method-I, et seq., wherein the CNS disease, disorder, or
injury, refers to damage that directly or indirectly affects the
normal functioning of the CNS. [0111] 1.3. Any of preceding
Method-I, et seq., wherein the CNS disease, disorder, or injury can
be a structural, physical, or mechanical impairment and may be
caused by physical impact, e.g., crushing, compression, or
stretching of nerve fibers. [0112] 1.4. Any of preceding Method-I,
et seq., wherein the CNS disease, disorder, or injury is a spinal
cord injury. [0113] 1.5. Method of 1.4, wherein the PDE1 inhibitor
slows or arrests the progression of the spinal cord injury. [0114]
1.6. Any of preceding Method-I, et seq., wherein the PDE1 inhibitor
slows or arrests axonal filament degradation. [0115] 1.7. Any of
preceding Method-I, et seq. wherein the CNS disease, disorder, or
injury relates to motor neuron trauma. [0116] 1.8. Any of preceding
Method-I, et seq., wherein the disease, disorder, or injury is
selected from the group consisting of: neurological traumas and
injuries, surgery related trauma and/or injury, retinal injury and
trauma, injury related to epilepsy, spinal cord injury, brain
injury, brain surgery, trauma related brain injury, trauma related
to spinal cord injury, brain injury related to cancer treatment,
spinal cord injury related to cancer treatment, brain injury
related to infection, brain injury related to inflammation, spinal
cord injury related to infection, spinal cord injury related to
inflammation, brain injury related to environmental toxins, and
spinal cord injury related to environmental toxins. [0117] 1.9. Any
of preceding Method-I, et seq., wherein the CNS disease, disorder,
or injury includes neuron or nerve fibers destroyed by or degraded
by an illness (e.g., Parkinson's Disease), a chemical imbalance, or
a physiological malfunction such anoxia (e.g., stroke), aneurysm,
or reperfusion injury. [0118] 1.10. Any of preceding Method-I, et
seq., wherein the CNS disease, disorder, or injury is a
neurodegenerative disorder. [0119] 1.11. Method of 1.10, wherein
the neurodegenerative disease, disorder, or injury is selected from
the group consisting of: Alzheimer's disease, Multiple Sclerosis,
Spinal Muscular Atrophy, Glaucoma, Frontotemporal dementia,
Dementia with Lewy bodies, Corticobasal degeneration, Progressive
supranuclear palsy, Prion disorders, Huntington's disease, Multiple
system atrophy, Parkinson's disease, Amyotrophic lateral sclerosis,
Hereditary spastic paraparesis, Spinocerebellar atrophies,
Friedreich's ataxia, Amyloidoses, Metabolic (diabetes) related
disorders, Toxin related disorders, chronic CNS inflammation,
Charcot Marie Tooth disease, diabetic neuropathy, injury due to
cancer chemotherapy (e.g., by vinca alkaloids and doxorubicin),
brain damage associated with stroke, ischemia associated with
stroke, and neurological disorders including, but not limited to,
various peripheral neuropathic and neurological disorders related
to neurodegeneration including, but not limited to: trigeminal
neuralgia, glossopharyngeal neuralgia, Bell's palsy, myasthenia
gravis, muscular dystrophy, amyotrophic lateral sclerosis,
progressive muscular atrophy, progressive bulbar inherited muscular
atrophy, herniated, ruptured or prolapsed vertebral disk syndromes,
cervical spondylosis, plexus disorders, thoracic outlet destruction
syndromes, peripheral neuropathies such as those caused by e.g.,
lead, acrylamides, gamma-diketones, carbon disulfide, dapsone,
ticks, porphyria, and Gullain-Barre syndrome. [0120] 1.12. Any of
preceding Method-I, et seq., wherein the CNS disease, disorder, or
injury is a CNS lesion, a seizure or injury due to seizures (e.g.,
epileptic seizures), radiation injury, injury due to chemotherapy
and/or stroke or other ischemic injury. [0121] 1.13. Any of
preceding Method-I, et seq., wherein the administration of the PDE1
inhibitor is used to replenish, replace, and/or supplement neurons
and/or glial cells. [0122] 1.14. Any of preceding Method-I, et
seq., wherein the PDE1 inhibitor is administered to a subject or a
patient in need thereof. [0123] 1.15. Any of preceding Method-I, et
seq., wherein the PDE1 inhibitor elevates the level or expression
of intracellular cAMP. [0124] 1.16. Any of preceding Method-I, et
seq., wherein the PDE1 inhibitor decreases the level or expression
of intracellular cAMP. [0125] 1.17. Any of preceding Method-I, et
seq., wherein the PDE1 modulates activity of PKA or PKG. [0126]
1.18. Any of preceding Method-I, et seq., wherein the PDE1
inhibitor increases the activity of PKA or PKG. [0127] 1.19. Any of
preceding Method-I, et seq., wherein the administration of the PDE1
inhibitor increases the level of both cAMP and cGMP. [0128] 1.20.
Any of preceding Method-I, et seq., wherein the administration of
the PDE1 inhibitor elevates the level of intracellular cAMP, and
wherein this increased level intracellular cAMP has neuroprotective
and/or neuroregenerative effects. [0129] 1.21. Any of preceding
Method-I, et seq., comprising administration of an effective amount
of the PDE1 inhibitor to a patient that suffers from a disease or
disorder related to elevated (e.g., chronically elevated)
intracellular calcium levels, and wherein the PDE1 inhibitor
prevents a further rise in said calcium levels. [0130] 1.22. Any of
preceding Method-I, et seq., wherein the PDE1 inhibitor is
administered either alone or in combination with another active
agent. [0131] 1.23. Any of preceding Method-I, et seq., wherein the
disease, disorder, or injury is related to motor neurons, and
wherein the motor neuron disease, disorder, or injury is Multiple
Sclerosis. [0132] 1.24. Any of preceding Method-II, et seq.,
wherein the PDE1 inhibitor is administered in combination with
another active agent in order to treat Multiple Sclerosis. [0133]
1.25. The method of 2.11, wherein the active agent is selected from
the group consisting of: Interferon, Glatiramer acetate,
Natalizumab, Gilenya.RTM. (fingolimod), Fampyra.RTM.,
immunosuppresents, and corticoids.
[0134] In another embodiment the invention provides for Method II,
wherein Method II comprises compositions and methods of treatment
or prophylaxis of a peripheral nervous system (PNS) disease,
disorder, or injury, wherein the method comprises administration of
an effective amount of a PDE1 inhibitor (e.g., any compound of
Formula V or 1.1-1.14) to increase intracellular levels of
cAMP.
[0135] For example, Method II also includes: [0136] 2.1. Method II,
wherein the PNS disease, disorder, or injury, refers to damage that
directly or indirectly affects the normal functioning of the CNS.
[0137] 2.2. Any of preceding Method-II, et seq., wherein the PDE1
inhibitor is administered to a subject or a patient in need
thereof. [0138] 2.3. Any of preceding Method-II, et seq., wherein
the PDE1 inhibitor elevates the level or expression of
intracellular cAMP. [0139] 2.4. Any of preceding Method-II, et
seq., wherein the PDE1 inhibitor (e.g., directly or indirectly)
modulates activity of PKA and/or PKG. [0140] 2.5. Any of preceding
Method-II, et seq., wherein the PDE1 inhibitor (e.g., directly or
indirectly) increases the activity of PKA and/or PKG. [0141] 2.6.
Any of preceding Method-II, et seq., wherein the administration of
the PDE1 inhibitor increases the level of cAMP and/or cGMP. [0142]
2.7. Any of preceding Method-II, et seq., wherein the
administration of the PDE1 inhibitor elevates the level of
intracellular cAMP, and wherein this increased level intracellular
cAMP levels protects nerve fibers, regenerates nerve fibers, or
promotes nerve fiber growth (e.g., axonal regeneration). [0143]
2.8. Any of preceding Method-II, et seq., comprising administration
of an effective amount of the PDE1 inhibitor to a patient that
suffers from a disease or disorder related to elevated (e.g.,
chronically elevated) intracellular calcium levels. [0144] 2.9. Any
of preceding Method-II, et seq., wherein the PDE1 inhibitor is
administered either alone or in combination with another active
agent. [0145] 2.10. The method of 2.9, wherein the active agent is
selected from the IGF (e.g., IGF-1) or a steroid. [0146] 2.11. Any
of preceding Method-II, et seq. wherein the PNS disease, disorder,
or injury is selected from the group consisting of: neuropathy
(e.g., peripheral neuropathy, autonomic neuropathy, and
mononeuropathy), sciatica, carpal tunnel syndrome, polyneuropathy,
diabetic neuropathy, postherpetic neuralgia, and thoracic outlet
syndrome.
[0147] In another embodiment the invention provides for Method III,
wherein Method III comprises compositions and methods to prevent a
CNS disease or disorder in a subject that is at risk for developing
said disease or disorder, wherein the method comprises: [0148] 1.)
Obtaining a sample from the subject; [0149] 2.) Measuring the
levels of intracellular calcium from the sample; [0150] 3.)
Comparing the levels of intracellular calcium in the biological
sample to a reference standard; [0151] 4.) Determining whether a
patient is at risk for developing a CNS disease or disorder based
upon the level of intracellular calcium compared to the reference
standard; [0152] 5.) Administering a PDE1 inhibitor (e.g., a
compound of any of Formula V or 1.1-1.14) to a subject based upon
the subject's levels of intracellular calcium (e.g., administration
of a PDE1 inhibitor to a subject because they have elevated
intracellular calcium levels compared to the reference
standard).
[0153] For example, Method III also includes: [0154] 3.1. Method
III, wherein the sample is a biological sample. [0155] 3.2. Any of
preceding Method-III, et seq., wherein the patient's intracellular
calcium levels are measured using a chemical fluorescent probe.
[0156] 3.3. Any of preceding Method-III, et seq., wherein the
patient's intracellular calcium levels are elevated compared to a
control (e.g., reference standard). [0157] 3.4. Any of preceding
Method-III, et seq., wherein a PDE1 inhibitor is administered to a
patient that is shown to have elevated intracellular calcium levels
compared to a control (e.g., reference standard). [0158] 3.5. Any
of preceding Method-III, et seq., wherein the administration of a
PDE1 inhibitor slows or prevents the development of a CNS and/or
PNS disease or disorder, wherein the CNS disease or disorder is one
that correlates to elevated (e.g., chronically elevated) levels of
intracellular calcium. [0159] 3.6. Any of preceding Method-III, et
seq., wherein the administration of a PDE1 inhibitor decreases the
likelihood that an individual will develop a CNS and/or PNS disease
or disorder, wherein the CNS and/or PNS disease or disorder is one
that correlates with elevated (e.g., chronically elevated) levels
of intracellular calcium (e.g., any of the diseases, disorders or
injuries listed in Method I, et seq., and Method II, et seq.).
[0160] 3.7. Any of preceding Method-III, et seq., wherein the
method optionally comprises measuring the patient's intracellular
levels of cAMP or cGMP. [0161] 3.8. Any of preceding Method-III, et
seq., wherein the PDE1 inhibitor is administered either alone or in
combination with another active agent. [0162] 3.9. Any of preceding
Method-III, et seq., wherein the PDE1 inhibitor is administered
because a patient has low levels of cAMP and/or cGMP compared to a
control subject.
[0163] 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.
[0164] In another embodiment, the invention also provides methods
of treatment, wherein the method comprises administering an
effective amount of a PDE1 inhibitor (e.g., any compound of Formula
V or 1.1-1.14) to treat any one or more of the following
conditions: [0165] (i) Neurodegenerative diseases, including
Parkinson's disease, restless leg, tremors, dyskinesias,
Huntington's disease, Alzheimer's disease, and drug-induced
movement disorders; [0166] (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; [0167]
(iii) Circulatory and cardiovascular disorders, including
cerebrovascular disease, stroke, congestive heart disease,
hypertension, pulmonary hypertension, e.g., pulmonary arterial
hypertension, and sexual dysfunction, including cardiovascular
diseases and related disorders as described in International
Application No. PCT/US2014/16741, the contents of which are
incorporated herein by reference; [0168] (iv) Respiratory and
inflammatory disorders, including asthma, chronic obstructive
pulmonary disease, and allergic rhinitis, as well as autoimmune and
inflammatory diseases; [0169] (v) Diseases that may be alleviated
by the enhancement of progesterone-signaling such as female sexual
dysfunction; [0170] (vi) A disease or disorder such as psychosis,
glaucoma, or elevated intraocular pressure; [0171] (vii) Traumatic
brain injury; [0172] (viii) 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 [0173]
(ix) 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 (e.g., any compound of Formula V or 1.1-1.14), in free or
pharmaceutically acceptable salt or prodrug form, to a human or
animal patient in need thereof.
[0174] In one aspect, the invention provides methods of treatment
or prophylaxis for narcolepsy. In this embodiment, PDE1 Inhibitors
(e.g., any compound of Formula V or 1.1-1.14) 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
therapeutically effective amounts of [0175] (i) a PDE1 Inhibitor,
e.g., a compound according to any of (e.g., any compound of Formula
V or 1.1-1.14), and [0176] (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 or
pharmaceutically acceptable salt or prodrug form, to a human or
animal patient in need thereof.
[0177] In another aspect, 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 V or 1.1-1.14, in free
or pharmaceutically acceptable salt or prodrug form, to a human or
animal patient in need thereof. Diseases or conditions 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, autoimmune disease, multiple sclerosis, prostate
enlargement, prostate cancer, and hypothyroidism. For example, by
enhancing progesterone signaling, the PDE1 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 PDE1 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.
[0178] In this aspect, PDE1 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 therapeutically effective
amounts of [0179] (i) a PDE1 Inhibitor, e.g., a compound according
to any of Formula V or 1.1-1.14, and [0180] (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 or pharmaceutically acceptable
salt or prodrug form, to a human or animal patient in need
thereof.
[0181] 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., a compound according to any
of Formula V or 1.1-1.14, in free or pharmaceutically acceptable
salt or prodrug form, sufficient to inhibit PDE1 activity.
[0182] 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., a compound
according to any of Formula V or 1.1-1.14, in free or
pharmaceutically acceptable salt or prodrug form, that inhibits
PDE1, wherein PDE1 activity modulates phosphorylation of DARPP-32
and/or the GluR1 AMPA receptor.
[0183] 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 PDE1 Inhibitor of the Invention, e.g., a compound
according to any of Formula V or 1.1-1.14, in free or
pharmaceutically acceptable salt form, in an ophthalmically
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.
[0184] The invention further provides a pharmaceutical composition
for topical ophthalmic use comprising a PDE1 inhibitor; for example
an ophthalmic solution, suspension, cream or ointment comprising a
PDE1 Inhibitor of the Invention, e.g., a compound according to any
of Formula V or 1.1-1.14, in free or ophthalmologically acceptable
salt form, in combination or association with an ophthalmologically
acceptable diluent or carrier.
[0185] Optionally, the PDE1 inhibitor (e.g., any of Formula V or
1.1-1.14) 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 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.
[0186] 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., a compound according to any of
Formula V or 1.1-1.14, 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.
[0187] In one aspect, 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.
[0188] 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., [0189] 1. Prostaglandin analogs such as latanoprost
(Xalatan), bimatoprost (Lumigan) and travoprost (Travatan), which
increase uveoscleral outflow of aqueous humor. Bimatoprost also
increases trabecular outflow. [0190] 2. Topical beta-adrenergic
receptor antagonists such as timolol, levobunolol (Betagan), and
betaxolol, which decrease aqueous humor production by the ciliary
body. [0191] 3. Alpha.sub.2-adrenergic agonists such as brimonidine
(Alphagan), which work by a dual mechanism, decreasing aqueous
production and increasing uveo-scleral outflow. [0192] 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-agonist action. [0193] 5. Miotic agents
(para-sympathomimetics) like pilocarpine work by contraction of the
ciliary muscle, tightening the trabecular meshwork and allowing
increased outflow of the aqueous humour. [0194] 6. Carbonic
anhydrase inhibitors like dorzolamide (Trusopt), brinzolamide
(Azopt), acetazolamide (Diamox) lower secretion of aqueous humor by
inhibiting carbonic anhydrase in the ciliary body. [0195] 7.
Physostigmine is also used to treat glaucoma and delayed gastric
emptying.
[0196] For example, the invention provides pharmaceutical
compositions comprising a PDE1 Inhibitor of the Invention, e.g., a
compound according to any of Formula V or 1.1-1.14, in free or
pharmaceutically acceptable salt form, 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, in combination or association with a
pharmaceutically acceptable diluent or carrier. For example, the
invention provides ophthalmic formulations comprising a PDE-1
Inhibitor of the Invention, e.g., a compound according to any of
Formula V or 1.1-1.14, 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.
[0197] The PDE1 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.
[0198] In yet another example, the PDE1 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.
[0199] In addition to the above-mentioned methods, it has also been
surprisingly discovered that PDE1 inhibitors (e.g., any of Formula
V or 1.1-1.14) 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.
[0200] 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., a compound according to any of Formula V or 1.1-1.14, in free
or pharmaceutically acceptable salt form, to a patient in need
thereof.
[0201] 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 therapeutically effective amounts of: [0202] (i)
a PDE1 Inhibitor of the invention, in free or pharmaceutically
acceptable salt form; and [0203] (ii) an antipsychotic, e.g.,
[0204] Typical antipsychotics, e.g., [0205] Butyrophenones, e.g.
Haloperidol (Haldol, Serenace), Droperidol (Droleptan); [0206]
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); Thioxanthenes, e.g., Chlorprothixene, Flupenthixol
(Depixol, Fluanxol), Thiothixene (Navane), Zuclopenthixol
(Clopixol, Acuphase); [0207] Atypical antipsychotics, e.g., [0208]
Clozapine (Clozaril), Olanzapine (Zyprexa), Risperidone
(Risperdal), Quetiapine (Seroquel), Ziprasidone (Geodon),
Amisulpride (Solian), Paliperidone (Invega), Aripiprazole
(Abilify), Bifeprunox; norclozapine, in free or pharmaceutically
acceptable salt form, to a patient in need thereof.
[0209] In a particular embodiment, the Compounds of the Invention
are particularly useful for the treatment or prophylaxis of
schizophrenia.
[0210] 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.
[0211] 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, in free or
pharmaceutically acceptable salt form, to the eye of a patient in
need thereof.
[0212] 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., a compound according to any of
Formula V or 1.1-1.14, 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.
[0213] The present invention also provides [0214] (i) a Compound of
the Invention, e.g., a compound according to any of Formula V or
1.1-1.14, as hereinbefore described, in free or pharmaceutically
acceptable salt form for example for use in any method or in the
treatment of any disease or condition as hereinbefore set forth,
[0215] (ii) the use of a Compound of the Invention, e.g., a
compound according to any of Formula V or 1.1-1.14, as hereinbefore
described, in free or pharmaceutically acceptable salt form, (in
the manufacture of a medicament) for treating any disease or
condition as hereinbefore set forth, [0216] (iii) a pharmaceutical
composition comprising a Compound of the Invention, e.g., a
compound according to any of Formula V or 1.1-1.14, as hereinbefore
described, in free or pharmaceutically acceptable salt form, in
combination or association with a pharmaceutically acceptable
diluent or carrier, and [0217] (iv) a pharmaceutical composition
comprising a Compound of the Invention, e.g., a compound according
to any of Formula V or 1.1-1.14, as hereinbefore described, in free
or 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.
[0218] Therefore, the invention provides use of a Compound of the
Invention, e.g., a compound according to any of Formula V or
1.1-1.14, as hereinbefore described, in free or 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 any one
or more of the following diseases: Parkinson's disease, restless
leg, tremors, dyskinesias, Huntington's disease, Alzheimer's
disease, and/or 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, e.g., pulmonary arterial hypertension, and/or sexual
dysfunction; asthma, chronic obstructive pulmonary disease, and/or
allergic rhinitis, as well as autoimmune and inflammatory diseases;
and/or 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,
and/or estrogen-induced endometrial hyperplasia and/or carcinoma;
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.
[0219] The invention also provides use of a Compound of the
Invention, in free or pharmaceutically acceptable salt form, (the
manufacture of a medicament) for the treatment or prophylactic
treatment of any one or more of: [0220] a) glaucoma, elevated
intraocular pressure, [0221] 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,
[0222] c) traumatic brain injury, and/or [0223] d) central and
peripheral degenerative disorders particularly those with
inflammatory components.
[0224] 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 V or 1.1-1.14.
[0225] 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.
[0226] For methods of treatment, the word "therapeutically
effective amount" as used herein refers to an amount of a drug
(e.g., a PDE1 inhibitor) sufficient to treat or ameliorate the
pathological effects a CNS or PNS disease, disorder, or injury. For
example, a therapeutically effective amount of a PDE1 inhibitor may
be an amount sufficient to, e.g., increase intracellular levels of
cAMP or cGMP, decrease intracellular levels of calcium, and/or
increase neuroregeneration. Where relevant, a therapeutically
effective amount may also be the amount of a PDE1 inhibitor
necessary to slow or prevent the development of CNS or PNS disease
or disorder.
[0227] The term "patient" or "subject" refers to human or non-human
(i.e., animal) patient. In a particular embodiment, the invention
encompasses both human and nonhuman patients. In another
embodiment, the invention encompasses nonhuman patients. In other
embodiment, the term encompasses human patients.
[0228] The term "control subject" as used herein, refers to any
human or nonhuman organism that does not have and/or is not
suspected of having a CNS or PNS disorder, syndrome, disease,
condition and/or symptom. The term "reference standard" as used
herein, refers to the prior measurement and obtaining of results in
a control subject or population of control subjects. In another
aspect, the term "reference standard" refers to the prior
measurement and obtaining of results in a patient prior to his or
her development of a CNS or PNS disorder, syndrome, disease,
condition and/or symptom.
[0229] The term "biological sample" as used herein, may include any
sample comprising biological material obtained from, e.g., an
organism, body fluid, waste product, cell or part of a cell
thereof, cell line, biopsy, tissue culture or other source
containing a intracellular calcium, cAMP, or cGMP levels.
[0230] A "neurogenic agent" is defined as a chemical agent or
reagent that can promote, stimulate, or otherwise increase the
amount or degree or nature of neurogenesis in vivo or ex vivo or in
vitro, relative to the amount, degree, or nature of neurogenesis in
the absence of the agent or reagent.
[0231] A "CNS injury" as used herein may include, e.g., damage to
retinal ganglion cells, a traumatic brain injury, a stroke-related
injury, a cerebral aneurism-related injury, a spinal cord injury or
trauma, including monoplegia, diplegia, paraplegia, hemiplegia and
quadriplegia, a neuroproliferative disorder, or neuropathic pain
syndrome. A "PNS injury" as used herein may include, e.g., damage
to the spinal or cranial nerves, wherein that damage may include a
lesion or some acute or chronic trauma.
[0232] Compounds of the Invention, (e.g., any of Formula V or
1.1-1.14) 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 with or for co-administration with
other active agents.
[0233] 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.
[0234] 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
Example 1
7,8-Dihydro-2-(4-(pyridine-2-yl)benzyl)-3-(4-fluorophenylamino)-5,7,7-trim-
ethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00021##
[0235] (a)
7-(4-Methoxybenzyl)-5-methyl-2-(4-(pyridin-2-yl)benzyl)-2H-pyra-
zolo[3,4-d]pyrimidine-4,6(5H,7H)-dione
[0236] A suspension of
7-(4-methoxybenzyl)-5-methyl-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dion-
e (8.43 g, 29.4 mmol), 2-(4-(chloromethyl)phenyl)-pyridine (6.0 g,
29.4 mmol) and K.sub.2CO.sub.3 (4.07 g, 29.4 mmol) in DMF (100 mL)
is stirred at room temperature overnight. Solvent is removed under
reduced pressure. The obtained residue is treated with water (150
mL) and hexanes (25 mL). The mixture is stirred at room temperature
for an hour, and then filtered. The filter cake is washed with
water three times (3.times.50 mL), and then dried under vacuum to
give 13 g of crude product (yield: 97%), which is used in the next
step without further purification. MS (ESI) m/z 454.2
[M+H].sup.+.
(b)
5-Methyl-2-(4-(pyridin-2-yl)benzyl)-2H-pyrazolo[3,4-d]pyrimidine-4,6(5-
H,7H)-dione
[0237] TFA (50 mL) is added into a suspension of
7-(4-Methoxybenzyl)-5-methyl-2-(4-(pyridin-2-yl)benzyl)-2H-pyrazolo[3,4-d-
]pyrimidine-4,6(5H,7H)-dione (13 g, 28.7 mmol) in methylene
chloride (80 mL) to give a tan solution, and then TFMSA (4 mL) is
added. The reaction mixture is stirred at room temperature
overnight. Solvents are removed under reduced pressure. The
obtained residue is treated with water (150 mL), cooled to
0.degree. C., and then adjusted to pH 8-9 with 28% ammonium
hydroxide (approx. 35 mL). After filtration, the obtained solids
are washed with water three times (3.times.50 mL), and then dried
under vacuum to give 12.8 g of crude product (crude yield: 134%),
which is used in the next step without further purification. MS
(ESI) m/z 334.1 [M+H].sup.+.
(c)
6-Chloro-5-methyl-2-(4-(pyridin-2-yl)benzyl)-2H-pyrazolo[3,4-d]pyrimid-
in-4(5H)-one
[0238]
5-Methyl-2-(4-(pyridin-2-yl)benzyl)-2H-pyrazolo[3,4-d]pyrimidine-4,-
6(5H,7H)-dione (8.5 g, 25.5 mmol) is suspended in POCl.sub.3 (300
mL), and then slowly heated to reflux. After the mixture is
refluxed for 30h, POCl.sub.3 is removed under reduced pressure. The
obtained residue is treated with water (300 mL), cooled to
0.degree. C., and then adjusted to pH 8-9 with 28% ammonium
hydroxide (approx. 30 mL). After filtration, the obtained solids
are washed with water five times (5.times.50 mL), and then dried
under vacuum to give 8.6 g of crude product (crude yield: 96%),
which is used in the next step without further purification. MS
(ESI) m/z 352.1 [M+H].sup.+.
(d)
6-(1-Hydroxy-2-methylpropan-2-ylamino)-5-methyl-2-(4-(pyridin-2-yl)ben-
zyl)-2H-pyrazolo[3,4-d]pyrimidin-4(5H)-one
[0239] A mixture of
6-Chloro-5-methyl-2-(4-(pyridin-2-yl)benzyl)-2H-pyrazolo[3,4-d]pyrimidin--
4(5H)-one (4.0 g, 11 mmol), 2-amino-2-methylpropan-1-ol (6.5 mL, 71
mmol) and DIPEA (3.4 mL, 20 mmol) in DMA (20 mL) is heated at
130.degree. C. for an hour. Solvent is removed under reduced
pressure. The obtained residue is treated with water (200 mL).
After filtration, the filter cake is washed with water twice
(2.times.50 mL), and then dried under vacuum to give 3.7 g of crude
product (crude yield: 80%), which is used in the next step without
further purification. MS (ESI) m/z 405.2 [M+H].sup.+.
(e)
7,8-Dihydro-2-(4-(pyridin2-yl)benzyl)-5,7,7-trimethyl-[2H]-imidazo-[1,-
2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0240] Thionyl chloride (756 .mu.L, 10.4 mmol) is added dropwise to
a solution of crude
6-(1-hydroxy-2-methylpropan-2-ylamino)-5-methyl-2-(4-(pyridin-2-yl)benzyl-
)-2H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (4.2 g, 10.4 mmol) in DMF
(84 mL). The reaction mixture is stirred at room temperature for 20
min. Water (5 mL) is added to quench the reaction. Solvents are
removed under reduced pressure. The obtained residue is treated
with methylene chloride, and then washed with 5% NaHCO.sub.3
aqueous solution three times. The organic phase is evaporated to
dryness to give 6.1 g of crude product (crude yield: 152%), which
is used in the next step without further purification. MS (ESI) m/z
387.2 [M+H].sup.+.
(f)
7,8-Dihydro-2-(4-(pyridin2-yl)benzyl)-3-chloro-5,7,7-trimethyl-[2H]-im-
idazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0241] 1.0M LiHMDS (55.4 mL, 55.4 mmol) in THF is added dropwise to
a solution of crude
7,8-dihydro-2-(4-(pyridin2-yl)benzyl)-5,7,7-trimethyl-[2H]-imidazo-[1,2-a-
]pyrazolo[4,3-e]pyrimidin-4(5H)-one (4.6 g, 11.9 mmol) and
hexachloroethane (2.58 g, 10.9 mmol) in methylene chloride (130 mL)
at 0.degree. C. The reaction mixture is stirred at 0.degree. C. for
30 min, and then quenched with water (100 mL) and methylene
chloride (150 mL). The organic phase is washed with water three
times (3.times.70 mL), and then evaporated to dryness. The obtained
crude product is purified on a neutral aluminum oxide column to
give 1.5 g of pure product (HPLC purity: 96%; yield: 30%). MS (ESI)
m/z 421.1 [M+H].sup.+.
(g)
7,8-Dihydro-2-(4-(pyridin2-yl)benzyl)-3-(4-fluorophenylamino)-5,7,7-tr-
imethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0242]
7,8-Dihydro-2-(4-(pyridin2-yl)benzyl)-3-chloro-5,7,7-trimethyl-[2H]-
-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one (550 mg, 1.31
mmol), 4-fluorobenzenamine (125 .mu.L, 1.31 mmol) and potassium
carbonate (361 mg, 2.61 mmol) in tert-amyl alcohol (3 mL) are
degassed with argon and then Xantphos (15 mg, 0.026 mmol) and
Pd.sub.2(dba).sub.3 (12 mg, 0.013 mmol) are added. The suspension
is degassed again, and then slowly heated to 110.degree. C. The
reaction mixture is stirred at 110.degree. C. under argon
overnight. Another batch of Pd.sub.2(dba).sub.3 (12 mg) and
Xantphos (15 mg) is added. The reaction is heated at 110.degree. C.
for additional 24 h for complete conversion. After routine workup,
the crude product is purified by silica-gel column chromatography
to give 352 mg of final product as a beige solid (HPLC purity:
97.4%; yield: 54%). .sup.1H NMR (500 MHz, Chloroform-d) .delta.
8.68 (dt, J=4.7, 1.3 Hz, 1H), 7.88 (d, J=8.3 Hz, 2H), 7.74 (td,
J=7.7, 1.8 Hz, 1H), 7.68 (d, J=8.0 Hz, 2H), 7.23 (ddd, J=7.4, 4.8,
1.2 Hz, 1H), 7.06 (d, J=8.3 Hz, 2H), 7.00-6.93 (m, 2H), 6.94-6.87
(m, 2H), 6.79 (s, 1H), 4.90 (s, 2H), 3.71 (s, 2H), 3.35 (s, 3H),
1.40 (s, 6H). MS (ESI) m/z 496.2 [M+H]+.
[0243] The compound of Example 1 shows good selectivity for PDE1
and inhibts PDE activity at an IC.sub.50 value of equal to or less
than 5 nM.
Example 2
7,8-Dihydro-2-(4-(6-Fluoropyridin-2-yl)benzyl)-3-(4-fluorophenylamino)-5,7-
,7-trimethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00022##
[0245] The synthesis method is analogous to example 1 wherein
2-(4-(chloromethyl)phenyl)-6-fluoropyridine is added in step (a)
instead of 2-(4-(chloromethyl)phenyl)-pyridine. Final product is
obtained as a off-white solid (HPLC purity: 99%). .sup.1H NMR (500
MHz, Chloroform-d) .delta. 7.89 (d, J=8.4 Hz, 2H), 7.83 (q, J=8.0
Hz, 1H), 7.58 (dd, J=7.5, 2.3 Hz, 1H), 7.05 (d, J=8.3 Hz, 2H),
7.00-6.84 (m, 6H), 4.91 (s, 2H), 3.76 (s, 2H), 3.39 (s, 3H), 1.47
(s, 6H). MS (ESI) m/z 514.3 [M+H]+
Example 3
7,8-Dihydro-2-(4-(pyridine-2-yl)benzyl)-3-(3,4-difluorophenylamino)-5,7,7--
trimethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00023##
[0246] (a)
2-(4-Bromobenzyl)-7,8-dihydro-5,7,7-trimethyl-[2H]-imidazo-[1,2-
-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0247] The title compound is synthesized using the procedure
analogous to the one described from step (a) to step (e) of Example
1 wherein 1-bromo-4-(bromomethyl)benzene was added in step (a)
instead of 2-(4-(chloromethyl)phenyl)-pyridine. MS (ESI) m/z 388.1
[M+H].sup.+.
(b)
2-(4-Phenoxybenzyl)-7,8-dihydro-5,7,7-trimethyl-[2H]-imidazo-[1,2-a]py-
razolo[4,3-e]pyrimidin-4(5H)-one
[0248]
2-(4-Bromobenzyl)-7,8-dihydro-5,7,7-trimethyl-[2H]-imidazo-[1,2-a]p-
yrazolo[4,3-e]pyrimidin-4(5H)-one (118 g, 304 mmol) is added to a
suspension of phenol (57 g, 606 mmol) and cesium carbonate (200 g,
614 mmol) in NMP (900 mL), followed by
2,2,6,6-tetramethylheptane-3,5-dione (7 mL, 33.5 mmol) and CuCl (15
g, 152 mmol). The reaction mixture is heated at 120.degree. C.
under nitrogen atmosphere for 10 h. After the completion of the
reaction, the mixture is diluted with water (4 L), and then
extracted with ethyl acetate. The combined organic phase is
evaporated to dryness. The obtained crude product is purified by
silica gel column chromatography to give 103 g of product (yield:
84%). MS (ESI) m/z 402.2 [M+H].sup.+.
(c)
7,8-Dihydro-5,7,7-trimethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimid-
in-4(5H)-one
[0249] TFA (600 mL) is added to a suspension of
2-(4-phenoxybenzyl)-7,8-dihydro-5,7,7-trimethyl-[2H]-imidazo-[1,2-a]pyraz-
olo[4,3-e]pyrimidin-4(5H)-one (103 g, 257 mmol) in methylene
chloride (210 mL) to give a tan solution, and then TFMSA (168 mL)
is added. The reaction mixture is stirred at room temperature until
the starting material disappears. The reaction mixture is poured
into cold water (3 L). After filtration, the filter cake is washed
with water twice, and then basified with ammonium hydroxide aqueous
solution, followed by adding ethyl acetate with stirring. The
precipitated solids are filtered, washed successively with water
three times, ethyl acetate twice and methanol once, and then dried
under vacuum to give 45 g of product (yield: 80%). MS (ESI) m/z
220.2 [M+H].sup.+.
(d)
7,8-Dihydro-2-(4-(pyridin-2-yl)benzyl)-5,7,7-trimethyl-[2H]-imidazo-[1-
,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0250] A suspension of
7,8-dihydro-5,7,7-trimethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin--
4(5H)-one (1.5 g, 6.84 mmol), 2-(4-(bromomethyl)phenyl)pyridine
(1.7 g, 6.84 mmol) and K.sub.2CO.sub.3 (2.83 g, 20.5 mmol) in DMF
(60 mL) is stirred at room temperature for 2-3 days. Solvent is
removed under reduced pressure. The obtained residue is treated
with water (100 mL), sonicated and then filtered. The filter cake
is dried under vacuum to give 2.19 g of crude product (yield: 83%),
which is used in the next step without further purification. MS
(ESI) m/z 387.1 [M+H].sup.+.
(e)
7,8-Dihydro-2-(4-(pyridine-2-yl)benzyl)-3-chloro-5,7,7-trimethyl-[2H]--
imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0251] 1.0M LiHMDS (3.0 mL, 3.0 mmol) in THF is added dropwise to a
solution of crude
7,8-dihydro-2-(4-(pyridin2-yl)benzyl)-5,7,7-trimethyl-[2H]-imidazo-[1,2-a-
]pyrazolo[4,3-e]pyrimidin-4(5H)-one (1.16 g, 3.0 mmol) and
hexachloroethane (2.13 g, 9.0 mmol) in methylene chloride (30 mL).
The reaction mixture is stirred at room temperature for 90 minutes,
and is then quenched with cold water (200 mL). The mixture is
extracted with methylene chloride three times (50 mL.times.3), and
the combined organic phase was washed with brine (30 mL), and then
evaporated to dryness under reduced pressure. The obtained residue
is purified on a neutral alumina oxide column to give 960 mg of
pure product as an off-white solid (HPLC purity: 96.8%; yield:
76%). MS (ESI) m/z 421.2 [M+H].sup.+.
(f)
7,8-Dihydro-2-(4-(pyridine-2-yl)benzyl)-3-(3,4-difluorophenylamino)-5,-
7,7-trimethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0252]
7,8-Dihydro-2-(4-(pyridin2-yl)benzyl)-3-chloro-5,7,7-trimethyl-[2H]-
-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one (230 mg, 0.546
mmol), 3,4-difluorobenzenamine (106 mg, 0.821 mmol) and potassium
carbonate (300 mg, 2.17 mmol) in tert-amyl alcohol (2.8 mL) are
degassed with argon, and then Xantphos (26 mg, 0.045 mmol) and
Pd.sub.2(dba).sub.3 (20 mg, 0.022 mmol) are added. The suspension
is degassed again, and then heated to 110.degree. C. The reaction
mixture is stirred at 110.degree. C. under argon overnight. After
routine workup, the crude product is purified on a basic alumina
oxide column to give 194 mg of final product as a beige solid (HPLC
purity: 99%; yield: 69%).
[0253] .sup.1H NMR (500 MHz, Chloroform-d) .delta. 8.69 (d, J=4.5
Hz, 1H), 7.88 (d, J=8.2 Hz, 2H), 7.76 (td, J=7.8, 1.6 Hz, 1H), 7.67
(d, J=7.9 Hz, 1H), 7.26-7.17 (m, 2H), 7.15 (d, J=8.2 Hz, 2H), 7.03
(m, 1H), 6.69 (m, 1H), 6.60 (m, 1H), 5.05 (s, 2H), 3.79 (s, 2H),
3.29 (s, 3H), 1.47 (s, 6H). MS (ESI) m/z 514.2 [M+H].sup.+.
Example 4
7,8-Dihydro-2-(4-(pyridin2-yl)benzyl)-3-(4-fluoro-3-methylphenylamino)-5,7-
,7-trimethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00024##
[0255] The synthesis method is analogous to example 3 wherein
4-fluoro-3-methylbenzenamine was added in step (f) instead of
3,4-difluorobenzenamine. Final product is obtained as an off-white
solid (HPLC purity: 97%). .sup.1H NMR (500 MHz, Chloroform-d)
.delta. 8.70 (ddd, J=4.8, 1.9, 1.0 Hz, 1H), 7.86 (d, J=8.3 Hz, 2H),
7.77 (td, J=7.7, 1.9 Hz, 1H), 7.68 (d, J=8.0 Hz, 1H), 7.26 (m, 1H),
7.06 (d, J=8.3 Hz, 2H), 6.97-6.86 (m, 2H), 6.81-6.69 (m, 2H), 4.91
(s, 2H), 3.81 (s, 2H), 3.40 (s, 3H), 2.13 (d, J=1.4 Hz, 3H), 1.49
(s, 6H). MS (ESI) m/z 510.2 [M+H].sup.+
Example 5
7,8-Dihydro-2-(4-(5-fluoropyridin2-yl)benzyl)-3-ethyl-5,7,7-trimethyl-[2H]-
-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00025##
[0256] (a)
7,8-Dihydro-2-(4-(5-fluoropyridin2-yl)benzyl)-3-chloro-5,7,7-tr-
imethyl-[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
[0257] The title compound is prepared using the procedure analogous
to the one described in steps (a) to (f) of Example 1 wherein
2-(4-(chloromethyl)phenyl)-5-fluoropyridine was added in step (a)
instead of 2-(4-(chloromethyl)phenyl)-pyridine. MS (ESI) m/z 439.2
[M+H].sup.+.
(b)
7,8-Dihydro-2-(4-(5-fluoropyridin2-yl)benzyl)-3-ethyl-5,7,7-trimethyl--
[2H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-on
[0258] Ethylmagnesium bromide (3.0 M in ether, 3 mL) is added
dropwise to a reaction vial containing ZnCl.sub.2 (1.2 g, 8.8 mmol)
at 0.degree. C. under argon. The mixture is stirred at room
temperature for 20 min, and is then cooled to -78.degree. C.
9-Methoxy-9-borabicyclo[3.3.1]nonane (1.0 M in hexanes, 8 mL) is
added dropwise. After the completion of the addition, the mixture
is stirred at room temperature for 40 min.
7,8-Dihydro-2-(4-(5-fluoropyridin2-yl)benzyl)-3-chloro-5,7,7-trimethyl-[2-
H]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one (352 mg, 0.8
mmol) in anhydrous DMF (15 mL) is slowly added to the mixture,
followed by 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl
(S-Phos, 38 mg) and palladium acetate (13 mg). The reaction vial is
sealed and stirred at room temperature for 30 min, and is then
heated at 100.degree. C. for 4 days. The mixture is diluted with
water (150 mL), and then extracted with dichloromethane (60
mL.times.3). The combined organic phase is evaporated to dryness
under reduced pressure. The residue is purified by a with a
semi-preparative HPLC system equipped with a reversed-phase C18
column using a gradient of 0-26% acetonitrile in water containing
0.1% formic acid over 16 min to give 177 mg of product as a pale
yellow solid (HPLC purity: 99.5%; yield: 51%). .sup.1H NMR (500
MHz, Chloroform-d) .delta. 8.53 (d, J=2.9 Hz, 1H), 7.92 (d, J=8.3
Hz, 2H), 7.69 (dd, J=8.8, 4.2 Hz, 1H), 7.47 (td, J=8.4, 2.9 Hz,
1H), 7.25 (d, J=9.0 Hz, 2H), 5.29 (s, 2H), 3.73 (s, 2H), 3.41 (s,
3H), 2.95 (q, J=7.6 Hz, 2H), 1.42 (s, 6H), 1.18 (t, J=7.5 Hz, 3H).
MS (ESI) m/z 433.3 [M+H].sup.+.
Example 6
7,8-Dihydro-2-(4-(6-fluoropyridin2-yl)benzyl)-3-ethyl-5,7,7-trimethyl-[2H]-
-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00026##
[0260] The title compound is prepared using the procedure analogous
to the one described in Example 5 wherein
2-(4-(chloromethyl)phenyl)-6-fluoropyridine was added in step (a)
instead of 2-(4-(chloromethyl)phenyl)-5-fluoropyridine. .sup.1H NMR
(400 MHz, Chloroform-d) .delta. 7.98 (d, J=8.4 Hz, 2H), 7.84 (m,
1H), 7.59 (dd, J=7.5, 2.4 Hz, 2H), 7.25 (d, J=8.4 Hz, 3H), 6.87
(dd, J=8.1, 3.0 Hz, 1H), 5.28 (s, 2H), 3.71 (s, 2H), 3.38 (s, 3H),
2.94 (q, J=7.5 Hz, 2H), 1.40 (s, 6H), 1.17 (t, J=7.5 Hz, 3H). MS
(ESI) m/z 433.2 [M+H].sup.+.
[0261] The compound of Example 5 shows good selectivity for PDE1
and inhibts PDE activity at an IC.sub.50 value of equal to or less
than 30 nM.
Example 7
7,8-Dihydro-2-(4-(5-fluoropyridin2-yl)benzyl)-3-propyl-5,7,7-trimethyl-[2H-
]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00027##
[0263] The title compound is prepared using the procedure analogous
to the one described in Example 5 wherein propylmagnesium bromide
was added in step (b) instead of ethylmagnesium bromide. MS (ESI)
m/z 447.2 [M+H].sup.+.
[0264] The compound of Example 7 shows good selectivity for PDE1
and inhibts PDE activity at an IC.sub.50 value of equal to or less
than 15 nM.
Example 8
7,8-Dihydro-2-(4-(6-fluoropyridin2-yl)benzyl)-3-propyl-5,7,7-trimethyl-[2H-
]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00028##
[0266] The title compound is prepared using the procedure analogous
to the one described in Example 5 wherein propylmagnesium bromide
was added in step (b) instead of ethylmagnesium bromide, and
2-(4-(chloromethyl)phenyl)-6-fluoropyridine was added in step (a)
instead of 2-(4-(chloromethyl)phenyl)-5-fluoropyridine. MS (ESI)
m/z 447.2 [M+H].sup.+.
Example 9
7,8-Dihydro-2-(4-chlorobenzyl)-3-(4-fluorophenylamino)-5,7,7-trimethyl-[2H-
]-imidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(5H)-one
##STR00029##
[0268] The title compound is prepared using the procedure analogous
to the one described in Example 1 wherein
1-chloro-4-(chloromethyl)benzene was added in step (a) instead of
2-(4-(chloromethyl)phenyl)-pyridine. MS (ESI) m/z 453.2
[M+H].sup.+
[0269] The compound of Example 9 shows good selectivity for PDE1
and inhibts PDE activity at an IC.sub.50 value of equal to or less
than 5 nM.
Example 10: Measurement of PDEIB Inhibition In Vitro Using IMAP
Phosphodiesterase Assay Kit
[0270] Phosphodiesterase I B (PDEIB) is a calcium/calmodulin
dependent phosphodiesterase enzyme that converts cyclic guanosine
monophosphate (cGMP) to 5'-guanosine monophosphate (5'-GMP). PDEIB
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.
[0271] 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-5 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.
[0272] In the phosphodiesterase assay, cGMP-fluorescein, which
cannot be bound to IMAP, and therefore retains little fluorescence
polarization, is converted to GMPfluorescein, which, when bound to
IMAP, yields a large increase in fluorescence polarization (mp).
Inhibition of phosphodiesterase, therefore, is detected as a
decrease in mp.
Enzyme Assay
[0273] 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.).
[0274] Assay: The following phosphodiesterase enzymes may be used:
3',5'-cyclic-nucleotide specific bovine brain phosphodiesterase
(Sigma, St. Louis, Mo.) (predominantly PDEIB) and recombinant full
length human PDE1 A and PDE1B (r-hPDE1 A 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.mol 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.
[0275] The FL-GMP conversion reaction is initiated by combining 4
parts enzyme and inhibitor mix with 1 part substrate solution
(0.225 .mu.L) 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 (mp).
[0276] A decrease in GMP concentration, measured as decreased mp,
is indicative of inhibition of PDE activity. IC.sub.50 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 AmP, which allows IC.sub.50
values to be estimated using nonlinear regression software (XLFit;
IDBS, Cambridge, Mass.)
[0277] Various compounds of Examples 1-9 demonstrate good
selectivity for PDE1, and can inhibit PDE1 at IC.sub.50 values
equal to or less than 50 nM in the present assay.
Example 11
[0278] A selective PDE1 inhibitor of the present invention
demonstrates microsomal stability in human microsomal stability
assays. The aforementioned selective PDE1 inhibitor demonstrates a
K value less than 0.01, and demonstrates a half-life of T1/2 of
about 100-1800 minutes.
Example 12
[0279] A selective PDE1 inhibitor of the present invention
demonstrates the ability to cross the blood-brain barrier.
Following an injection of 10 mg/kg in a suitable mouse model, the
aforementioned selective PDE1 inhibitor is detectable at about 3
.mu.M less than about 0.5 hours following the injection.
* * * * *