U.S. patent application number 13/870819 was filed with the patent office on 2014-01-16 for use of d-serine derivatives for the treatment of anxiety disorders.
This patent application is currently assigned to NPS Pharmaceuticals, Inc.. The applicant listed for this patent is NPS Pharmaceuticals, Inc.. Invention is credited to Guy Higgins, Methvin Isaac, Abdelmalik Slassi.
Application Number | 20140018549 13/870819 |
Document ID | / |
Family ID | 39511208 |
Filed Date | 2014-01-16 |
United States Patent
Application |
20140018549 |
Kind Code |
A1 |
Higgins; Guy ; et
al. |
January 16, 2014 |
USE OF D-SERINE DERIVATIVES FOR THE TREATMENT OF ANXIETY
DISORDERS
Abstract
Compounds of Formula I are useful for the treatment of anxiety
disorders such as generalized anxiety disorder (GAD), panic attack,
post traumatic stress disorder (PTSD), obsessive compulsive
disorder (OCD) and social phobias, wherein: A is chosen from: aryl
or heteroaryl, A being optionally substituted with up to 5
independently-selected groups R.sup.8; R.sup.1 is chosen from:
alkyl or haloalkyl; R.sup.2 is chosen from: H, C(O)R.sup.6,
C(O)OR.sup.6, SO2R.sup.6 or C(O)NR.sup.6R.sup.7; R.sup.3, R.sup.4
and R.sup.5 are independently chosen from: H or alkyl; R.sup.6 and
R.sup.7 are independently chosen from: H or alkyl; and R.sup.8 is
chosen from: OH, CN, halo, alkyl, alkoxy, haloalkyl, haloalkoxy,
C(O)R.sup.6, C(O)OR.sup.6, SO2R.sup.6 or C(O)NR.sup.6R.sup.7.
##STR00001##
Inventors: |
Higgins; Guy; (Toronto,
CA) ; Slassi; Abdelmalik; (Mississauga, CA) ;
Isaac; Methvin; (Brampton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NPS Pharmaceuticals, Inc.; |
|
|
US |
|
|
Assignee: |
NPS Pharmaceuticals, Inc.
Bedminster
NJ
|
Family ID: |
39511208 |
Appl. No.: |
13/870819 |
Filed: |
April 25, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12519041 |
Sep 22, 2009 |
8450336 |
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PCT/CA07/02256 |
Dec 14, 2007 |
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13870819 |
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60870008 |
Dec 14, 2006 |
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Current U.S.
Class: |
549/76 ; 560/29;
564/158; 564/165; 564/196; 564/99 |
Current CPC
Class: |
C07D 333/22 20130101;
C07C 271/22 20130101; C07C 233/15 20130101; A61K 31/165 20130101;
A61K 31/381 20130101; C07C 311/46 20130101; A61P 25/22 20180101;
C07C 233/51 20130101; C07C 233/11 20130101 |
Class at
Publication: |
549/76 ; 564/165;
564/196; 564/158; 560/29; 564/99 |
International
Class: |
C07D 333/22 20060101
C07D333/22; C07C 311/46 20060101 C07C311/46; C07C 233/51 20060101
C07C233/51; C07C 271/22 20060101 C07C271/22; C07C 233/11 20060101
C07C233/11; C07C 233/15 20060101 C07C233/15 |
Claims
1-20. (canceled)
21. A pharmaceutical composition for the treatment of an anxiety
disorder, the pharmaceutical composition comprising a
therapeutically effective amount of a compound of Formula I or a
salt, solvate or hydrate thereof: ##STR00053## wherein: A is chosen
from: aryl or heteroaryl, A being optionally substituted with up to
5 independently-selected groups R.sup.8; R.sup.1 is chosen from:
alkyl or haloalkyl; R.sup.2 is chosen from: H, C(O)R.sup.6,
C(O)OR.sup.6, SO.sub.2R.sup.6 or C(O)NR.sup.6R.sup.7; R.sup.3,
R.sup.4 and R.sup.5 are independently chosen from: H or alkyl;
R.sup.6 and R.sup.7 are independently chosen from: H or alkyl; and
R.sup.8 is chosen from: OH, CN, halo, alkyl, alkoxy, haloalkyl,
haloalkoxy, C(O)R.sup.6, C(O)OR.sup.6, SO.sub.2R.sup.6 or
C(O)NR.sup.6R.sup.7.
22. The pharmaceutical composition of claim 21, wherein the
compound is an R enantiomer having the following chemical formula:
##STR00054## or a salt, solvate or hydrate thereof.
23. The pharmaceutical composition of claim 21, wherein: R.sup.2 is
chosen from: H, C(O)R.sup.6, C(O)OR.sup.6, or SO.sub.2R.sup.6;
R.sup.3, R.sup.4 and R.sup.5 are each H; R.sup.6 is alkyl; and
R.sup.8 is chosen from: halo or alkyl.
24. The pharmaceutical composition of claim 23, wherein the
compound is an R enantiomer having the following chemical formula:
##STR00055## or a salt, solvate or hydrate thereof.
25. The pharmaceutical composition of claim 24, wherein: R.sup.1 is
chosen from: methyl or CHF.sub.2; and R.sup.6 is chosen from:
methyl or tert-butyl.
26. The pharmaceutical composition of claim 24, wherein; A is aryl,
optionally substituted with up to 5 independently-selected groups
R.sup.8; R.sup.2 is C(O)R.sup.6; and R.sup.8 is halo.
27. The pharmaceutical composition of claim 26, wherein; R.sup.1 is
haloalkyl; and R.sup.6 is methyl.
28. The pharmaceutical composition of claim 21, wherein the
compound is ##STR00056## or a salt, solvate or hydrate thereof.
29. The pharmaceutical composition of claim 21, wherein the
compound is chosen from: ##STR00057## or a salt, solvate or hydrate
thereof.
30. The pharmaceutical composition of claim 21, wherein the anxiety
disorder is chosen from: generalized anxiety disorder (GAD), panic
attack, post traumatic stress disorder (PTSD), obsessive compulsive
disorder (OCD) or social phobias.
Description
TECHNICAL FIELD
[0001] The present disclosure relates the use serine derivatives,
to processes for their preparation, to pharmaceutical compositions
containing them, and to their usefulness in the treatment of
anxiety disorders.
BACKGROUND
[0002] Anxiety is broadly defined as a state of unwarranted or
inappropriate worry often accompanied by restlessness, tension,
distraction, irritability and sleep disturbances.
[0003] This disproportionate response to environmental stimuli can
hyperactivate the hypothalamic-pituitary-adrenal axis and the
autonomic nervous system, resulting in somatic manifestation of
anxiety, including shortness of breath, sweating, nausea, rapid
heartbeat and elevated blood pressure (Sanford et al. Pharmacol.
Ther. 2000, 88: 197-212). Anxiety disorders represent a range of
conditions and as a result have been classified into multiple
distinct conditions, including generalized anxiety disorder (GAD),
panic attack, post traumatic stress disorder (PTSD), obsessive
compulsive disorder (OCD) and social phobias (Sanford et al. Acta.
Psychiatr. Scand. Suppl. 1998, 393: 74-80).
[0004] Generalized anxiety disorder (GAD) is the most common of the
anxiety disorders that is characterized by excessive and persistent
worries. In the general population the lifetime prevalence rate of
GAD range from 4.1 to 6.6% with somewhat higher rates in woman than
in man. The individual with GAD worries about life events such as
marital relationships, job performance, health, money and social
status. Individuals with GAD startle easily and may suffer from
depression. Some of the specific symptoms of GAD include
restlessness, motor tension, difficulty concentrating,
irritability, and sleep disturbances. The severity of the symptoms
over time may be linked to the changing nature of the environmental
stressor. With increasing age, GAD symptoms become less severe.
[0005] Panic Disorder is a well-studied psychiatric condition that
consists of multiple disabling panic attacks characterized by and
intense autonomic arousal. In addition, heightened fear and anxiety
states occur both during and between panic attacks. Approximately
3% of woman and 1.5% of men have panic attacks. During a panic
attack, the individual experiences multiple symptoms including
light-headedness, a pounding heart and difficulty in breathing.
Panic disorder may be caused by an oversensitive brain system
regulating autonomic functions. Potential brain regions involved in
panic attack are the locus ceruleus, hippocampus and amygdala.
Pathophysiology in the brain GABA-benzodiazepine receptor system
may also contribute to the production of panic attack.
[0006] Post traumatic stress disorder (PTSD) is another example of
a disorder associated with intense fear and anxiety states that
require psychiatric treatment. PSTD results from exposure to a life
threatening or traumatic event. Individuals with PSDT have
recurring thoughts of the terrifying event. Reenactment of the
event varies in duration from a few seconds or hours to several
days. Individuals with major depression, with panic disorders or
lacking strong social supports are vulnerable to develop PTSD
[0007] Anxiety disorders, which occur in 10% to 30% of the
population, represent not only a significant public health issue
but place a substantial economic burden on society. A number of
drugs have either been developed or are being developed for
treating the different subclasses of anxiety. Some of these agents
such as tricyclic antidepressants and b-adrenoreceptor antagonists
found either limited use in treating specific disorders such as
performance anxiety (e.g., b-adrenoreceptor antagonists suppression
of the sympathetic manifestations of anxiety) or have fallen out of
favor for reasons of efficacy and/or safety. Currently, direct and
indirect serotonin receptor agonists [e.g., selective serotonin
reuptake inhibitors (SSRI) and buspirone] and benzodiazepines are
most often prescribed for treating anxiety disorders with
benzodiazepine receptor agonist being a preferred therapeutic
modality. See Atack et al. Curr. Drug Targets. CNS. Neurol. Disord.
2003, 2: 213-232; Stahl et al. J. Clin. Psychiatry 2002, 63:
756-757; Uhlenhuth et al. J. Clin. Psychopharmacol. 1999, 19:
23S-24S; Varia et al. Int. Clin. Psychopharmacol. 2002, 17:
103-107; Vaswani et al. Prog. Neuropsychopharmacol. Biol.
Psychiatry 2003, 27: 85-102. The ability of benzodiazepines to
enhance g-aminobutyric acid (GABA) neurotransmission safely and
rapidly is central to their effectiveness in treating anxiety
disorder, especially GAD and panic disorders (Stahl et al. J. Clin.
Psychiatry 2002, 63: 756-757). Benzodiazepines act by positively
modulating the inhibitory neurotransmitter GABA through an
allosteric site on the GABA A receptor complex, a ligand-gated
chloride ion channel. Nonetheless, the use of benzodiazepines is
limited by side effects associated with enhanced GABAergic
neurotransmission, manifesting as sedation, muscle relaxation,
amnesia and ataxia. Moreover, the potential for abuse and physical
dependence is associated with the long-term use of benzodiazepines.
Furthermore, some forms of anxiety such as OCD are relatively
resistant to benzodiazepine treatment. These therapeutic
limitations and the societal burdens of anxiety provide the impetus
for the development of novel anxiolytics or anxioselective
agents.
[0008] The concept of anxioselectivity is used to describe
anxiolysis in the absence of side effects typically associated with
benzodiazepines. This search for alternative strategies to treat
anxiety disorders have led to the growing use of SSRIs, in addition
to a number of other molecular targets including metabotropic
glutamate receptors (mGluRs) that are currently under evaluation
(Schoepp et al Nat. Rev. Drug Dis. 2005, 4 (2): 131-144. However,
none of the alternative targets has been shown to match either the
efficacy or rapid onset of benzodiazepine.
[0009] The present invention is directed to the D-serine analogs
for the treatment of anxiety disorders such as generalized anxiety
disorder (GAD), panic attack, post traumatic stress disorder
(PTSD), obsessive compulsive disorder (OCD) and social phobias.
[0010] It has now been found that compounds of Formula I are useful
in the treatment of anxiety related disorders such as those denoted
above.
SUMMARY
[0011] We have discovered that compounds of Formula I:
##STR00002##
[0012] wherein:
[0013] A is chosen from: aryl or heteroaryl, A being optionally
substituted with up to 5 independently-selected groups R.sup.8;
[0014] R.sup.1 is chosen from: alkyl or haloalkyl;
[0015] R.sup.2 is chosen from: H, C(O)R.sup.6, C(O)OR.sup.6,
SO.sub.2R.sup.6 or C(O)NR.sup.6R.sup.7;
[0016] R.sup.3, R.sup.4 and R.sup.5 are independently chosen from:
H or alkyl;
[0017] R.sup.6 and R.sup.7 are independently chosen from: H or
alkyl; and
[0018] R.sup.8 is chosen from: OH, CN, halo, alkyl, alkoxy,
haloalkyl, haloalkoxy, C(O)R.sup.6, C(O)OR.sup.6, SO.sub.2R.sup.6
or C(O)NR.sup.6R.sup.7;
[0019] are useful in the treatment of anxiety disorders such as
generalized anxiety disorder (GAD), panic attack, post traumatic
stress disorder (PTSD), obsessive compulsive disorder (OCD) and
social phobias.
[0020] In another aspect of the disclosure compositions are
provided containing the present compounds in amounts for
pharmaceutical use to treat medical conditions such as anxiety
disorders such as generalized anxiety disorder (GAD), panic attack,
post traumatic stress disorder (PTSD), obsessive compulsive
disorder (OCD) and social phobias; such compositions comprise a
compound of Formula I in association with one or more
pharmaceutically acceptable diluents, excipients and/or inert
carriers.
DEFINITIONS
[0021] Unless specified otherwise within this specification, the
nomenclature used in this specification generally follows the
examples and rules stated in Nomenclature of Organic Chemistry,
Sections A, B, C, D, E, F, and H, Pergamon Press, Oxford, 1979,
which is incorporated by references herein for its exemplary
chemical structure names and rules on naming chemical structures.
Optionally, a name of a compound may be generated using a chemical
naming program: ACD/ChemSketch, Version 5.09/September 2001,
Advanced Chemistry Development, Inc., Toronto, Canada.
[0022] The term "alkyl" as used herein means a straight- or
branched-chain hydrocarbon radical having from one to six carbon
atoms, and includes methyl, ethyl, propyl, isopropyl, t-butyl and
the like.
[0023] The term "alkoxy" as used herein means a straight- or
branched-chain alkoxy radical having from one to six carbon atoms
and includes methoxy, ethoxy, propyloxy, isopropyloxy, t-butoxy and
the like.
[0024] The term "halo" as used herein means halogen and includes
fluoro, chloro, bromo, iodo and the like, in both radioactive and
non-radioactive forms.
[0025] The term "haloalkyl" as used herein means an alkyl group in
which at least one H atom has been replaced by a halo atom, and
includes groups such as CF.sub.3, CH.sub.2Br and the like.
[0026] The term "haloalkoxy" as used herein means an alkoxy group
in which at least one H atom has been replaced by a halo atom, and
includes groups such as OCF.sub.3, OCH.sub.2Br and the like.
[0027] The term "aryl" as used herein means an aromatic group
having five to twelve atoms, and includes phenyl, naphthyl and the
like.
[0028] The term "heteroaryl" means an aromatic group which includes
at least one heteroatom selected from at least one of the
following: N, S and O, and includes groups and includes pyridyl,
indolyl, furyl, benzofuryl, thienyl, benzothienyl, quinolyl,
oxazolyl and the like.
DETAILED DESCRIPTION
[0029] One embodiment of the disclosure provides compounds of
Formula I, or a salt or solvate thereof, for the treatment of
anxiety disorders such as generalized anxiety disorder (GAD), panic
attack, post traumatic stress disorder (PTSD), obsessive compulsive
disorder (OCD) and social phobias.
##STR00003##
[0030] wherein:
[0031] A is chosen from: aryl or heteroaryl, optionally substituted
with up to 5 independently-selected groups R.sup.8;
[0032] R.sup.1 is chosen from: alkyl or haloalkyl;
[0033] R.sup.2 is chosen from: C(O)R.sup.6, C(O)OR.sup.6,
SO.sub.2R.sup.6 or C(O)NR.sup.6R.sup.7;
[0034] R.sup.3, R.sup.4 and R.sup.5 are independently chosen from:
H or alkyl;
[0035] R.sup.6 and R.sup.7 are independently chosen from: H or
alkyl; and
[0036] R.sup.8 is chosen from: OH, CN, halo, alkyl, alkoxy,
haloalkyl, haloalkoxy, C(O)R.sup.6, C(O)OR.sup.6, SO.sub.2R.sup.6
or C(O)NR.sup.6R.sup.7.
[0037] Another embodiment provides compounds of Formula I in which
R.sup.1 is a haloalkyl group, or a salt or solvate thereof for the
treatment of anxiety disorders such as generalized anxiety disorder
(GAD), panic attack, post traumatic stress disorder (PTSD),
obsessive compulsive disorder (OCD) and social phobias.
[0038] The introduction of the haloalkyl group (R.sup.1) in
compounds of Formula I brings about dramatic changes in the
physical and chemical properties of the molecules as compared to
the analogous parent alkyl compounds, and can result in the
enhancement of pharmacokinetic properties and biological
activities. The unique properties of the fluorine atom include it
small size, low polarizability, high electronegativity and its
ability to form strong bonds with carbon. Recently, bioactive
compounds containing trifluoromethoxy, difluoromethoxy and
fluoromethoxy groups have attracted great interest. Replacement of
hydrogen atoms can sometimes result in improved thermal and
metabolic stability. Improved metabolic stability is usually a
desirable feature since the possibility exists that in vivo
decomposition may produce toxic effects.
[0039] The geminal combination of an alkoxyl or aryloxy group with
a fluorine atom offers the possibility of bonding/nonbonding
resonance, which can be formally expressed by the superposition of
a covalent and ionic limiting structure. This phenomenon, which
reveals itself as a lengthening and weakening of the carbon-halogen
bond and a shortening and strengthening of the carbon-oxygen bond
is widely known as the generalized anomeric effect [Schlosser et al
Chem. Rew. 2005, 105: 827-856].
[0040] Exemplary compounds useful in the practice of the invention
include, but is not limited to: [0041]
2-Amino-N-benzyl-3-(difluoromethoxy) propanamide, [0042]
2-Amino-3-difluoromethoxy-N-(4-fluorobenzyl) propionamide, [0043]
2-(Acetylamino)-N-benzyl-3-(difluoro-methoxy)propanamide, [0044]
2-(Acetylamino)-3-(difluoromethoxy)-N-(4-fluoro-benzyl)propanamide,
[0045] 2-(Acetylamino)-N-(3,4-difluorobenzyl)-3-(difluoromethoxy)
propanamide, [0046] tert-Butyl
{(1R)-2-(benzylamino)-1-[(difluoromethoxy)methyl]-2-oxoethyl}carbamate,
[0047] tert-Butyl
{(1R)-1-[(difluoromethoxy)methyl]-2-[(4-fluorobenzyl)
amino]-2-oxoethyl}carbamate, [0048]
(2R)-2-(Acetylamino)-N-benzyl-3-(difluoro-methoxy) propanamide,
[0049] tert-butyl {(1R)-1-[(difluoromethoxy)
methyl]-2-[(3-fluoro-benzyl amino]-2-oxoethyl}carbamate, [0050]
tert-butyl
{(1R)-1-[(difluoromethoxy)methyl]-2-[(3,4-difluorobenzyl)amino]-2-oxoethy-
l}carbamate, [0051] Tert-butyl
{(1R)-1-[(difluoromethoxy)methyl]-2-oxo-2-[(2-thienylmethyl)amino]ethyl}c-
arbamate, [0052] tert-butyl
{(1R)-1-[(difluoromethoxy)methyl]-2-[(4-methyl-benzyl)amino]-2-oxoethyl}c-
arbamate, [0053] tert-butyl
{(1R)-2-[(3-chlorobenzyl)amino]-1-[(difluoro-methoxy)methyl]-2-oxoethyl}c-
arbamate, [0054] tert-butyl
{(1R)-2-[(3-methylbenzyl)amino]-1-[(difluoro-methoxy)methyl]-2-oxoethyl}c-
arbamate, [0055] tert-butyl {(1R)-1-[(difluoromethoxy)
methyl]-2-oxo-2-[(3-thienylmethyl)amino]ethyl}carbamate, [0056]
(2R)-2-(Acetylamino)-3-(difluoromethoxy)-N-(4-fluorobenzyl)
propanamide, [0057]
(2R)--N-benzyl-3-(difluoromethoxy)-2-[(methyl-sulfonyl)amino]propa-
namide, [0058]
(2R)-3-(difluoromethoxy)-N-(4-fluorobenzyl)-2[(methylsulfonyl)amino]propa-
namide, [0059]
(2R)-2-(acetylamino)-N-(4-chlorobenzyl)-3-(difluoromethoxy)propanamide,
[0060]
(2R)-2-(acetylamino)-3-(difluoromethoxy)-N-(3-fluorobenzyl)propana-
mide, [0061]
(2R)-2-(acetylamino)-N-(3,4-difluorobenzyl)-3-(difluoromethoxy)propanamid-
e, [0062]
(2R)-2-(acetylamino)-3-(difluoromethoxy)-N-(2-thienylmethyl)prop-
anamide, [0063]
(2R)-2-(acetylamino)-3-(difluoromethoxy)-N-(4-methylbenzyl)propanamide,
[0064]
(2R)-2-(acetylamino)-N-(3-chlorobenzyl)-3-(difluoromethoxy)propana-
mide, [0065]
(2R)-2-(acetylamino)-3-(difluoromethoxy)-N-(3-methylbenzyl)propanamide,
[0066]
(2R)-2-(acetylamino)-3-(difluoromethoxy)-N-(3-thienylmethyl)propan-
amide, [0067]
2-Acetylamino-N-benzyl-3-difluoromethoxy-propionamide, [0068]
2-Acetylamino-3-difluoromethoxy-N-(4-fluoro-benzyl)-propionamide,
[0069]
2-Acetylamino-N-(3,4-difluoro-benzyl)-3-difluoromethoxy-propionami-
de; and [0070] lacosamide
((+)-(2R)-2-(acetylamino)-N-benzyl-3-methoxypropanamide).
[0071] Preparation of Compounds of Formula I.
[0072] WO 97/33861 discloses related compounds in which R.sup.1 is
alkyl, such as lacosamide:
##STR00004##
[0073] Compounds of Formula I in which R.sup.1 is haloalkyl may be
prepared as shown below.
[0074] Fluoro methyl ether derivatives [Manson et al J. Am. Chem.
Soc. 1956, 78: 1682] can be obtained from the corresponding chloro
analogs by nucleophilic substitution with KF. Chloromethylethers
are readily accessible [Hayashi et al Bull. Chem. Soc. Jpn 1980,
53: 2701; Marvel et al Org. Syn. Coll. Vol. 1941, 1: 369; Davis et
al Org. Synth. 1967, 47: 123.; Sharma et al J. Org. Chem. 1968, 33:
3335.; Hayami et al Bull. Chem. Soc. Jpn 1971, 44: 3091]. The
O-.alpha.-fluoro alkyl ethers can be most conveniently prepared
from the reaction of the vinyl ether with N-Bromosuccinimide (NBS)
in the presence of HF followed by reductive debromination.
O-.alpha.-fluoro alkyl ethers
##STR00005##
[0076] The O-.alpha.,.alpha.-difluoro alkyl ethers can be prepared
by electrophilic reactions of the appropriate alkoxide anion with
Chlorodifluoromethylation in the presence of base [Clark et al J.
Am. Chem. Soc. 1955, 77: 6618; Miller et al J. Org. Chem. 1960, 25:
2009, Sharma et al J. Fluorine. Chem. 1988, 41: 247];
difluorocarbene [Naumann et al J. Fluorine. Chem. 1994, 67: 91;
Naumann et al Liebigs. Ann. 1995, 1717-1719] and
difluoromethylcarbocation equivalent [Uneyama et al Tetrahedron
Lett. 1993, 34: 1311; Uneyama et al J. Org. Chem. 1995, 60:
370;].
[0077] Alternatively, the difluoromethyl ethers could also be
accessible by sulfur tetrafluoride mediated fluorodeoxygenation of
formates [Sheppard et al J. Org. Chem. 1964, 29: 1], or from the
treatment of the alcohol with Iododifluoromethyl phenyl sulphone to
give the corresponding ether which can undergo reductive
desulphonylation [Olah et al Org. Lett. 2005, 6: 4315].
O-.alpha.,.alpha.-difluoro alkyl ethers
##STR00006##
[0079] The O-.alpha.,.alpha.,.alpha.-trifluoro alkyl ethers can be
prepared by a recently disclosed fluorodesulfurization involving
the treatment of dithiocarbonates (xanthogenates) with excess
HF/Pyridine and 1,3-dibromo-5,5-dimethylhydantoin. The
trifluoromethyl ethers are usually formed in moderate to excellent
yield [Kanie et al Bull. Chem. Soc. Jpn 2000, 73: 471; Kanie et al
Adv. Synth. Catal. 2001, 343: 235].
O-.alpha.,.alpha.,.alpha.-trifluoro alkyl ethers
##STR00007##
[0081] Alkyl trifluoromethyl ethers can also be prepared by (1)
treating alkyfluoroformates with SF4 [Sheppard et al J. Org. Chem.
1964, 29: 11]; (2) trifluoromethyl transfer from
0-(trifluoromethyl) dibenzofuranium tetrafluoroborate [Umemoto, T.
Chem. Rew. 1996, 96: 1757] and (3) the addition of trifluoromethyl
hypofluorite (FOCF3) to alkenes[Rozen, S. Chem. Rew. 1996, 96:
1717].
[0082] As referred to above, individual compounds of Formula II
below, may be prepared according to various methods described above
utilizing the appropriately protected series as the representative
alcohol precursor.
[0083] Synthesis of Difluoromethoxy Compounds
[0084] A compound of Formula I wherein R.sup.1 is lower alkyl,
CHF.sub.2, CFH.sub.2 or halogenated alkyl, and A is aryl,
substituted aryl, alkyl or heteroaryl etc. can be prepared as shown
in Scheme 1, below.
[0085] The commercially available amino acid serine 1
(R.sup.3.dbd.H) can first be N-protected with G1 and G2 (e.g. G1=G2
is Benzyl) to provide N,N-dibenzylamino intermediate 2, which then
can be easily transformed into the ester precursor 3 (benzyl ester
derivative shown). The corresponding benzyl-ester 3 can be
converted to the difluoromethoxy derivative utilizing
difluoromethylating agents such as FSO.sub.2CF.sub.2COOH or
CF.sub.3ZnBr.2CH.sub.3CN, followed by deprotection conditions (e.g.
shown is hydrogenation) to afford the difluoromethoxyserine
precursor 4. Acylation of 4, utilizing procedures established in
the art with Boc.sub.2O or Ac.sub.2O among others to give
intermediate 5, which was subjected to amide bond formation using
known coupling procedures, provides the difluoromethoxy derivatives
of Formula II.
##STR00008##
[0086] An alternative synthesis of compound of Formula II wherein
R.sup.1 is CHF.sub.2 utilizes the difluoro
(phenylseleno)-methylcarbocation equivalent (obtained via a
Pummerer rearrangement of difluoromethyl phenyl selenoxide) and the
cyclic ether oxetane. The reaction of difluoromethyl phenyl
selenoxide 6 [Uneyama et al Tetrahedron Lett. 1993, 34: 1311;
Uneyama et al J. Org. Chem. 1995, 60: 370;] with oxetane 7 in
acetic anhydride should give the intermediate 8 which can undergo
reductive deselenation to afford 9. Hydrolysis of 9 followed by
oxidation should provide the difluoromethoxy acid 10. Activation of
acid 10 should give the oxazolidinones 11, which undergoes
.alpha.-azidation to afford 11. Staudinger reduction of 11 and
subsequent acetylation with acetic anhydride should give 12.
Treatment of 12 with the amine should provide the difluoromethoxy
derivatives of Formula II, as shown in Scheme 2, below.
##STR00009##
[0087] Another embodiment provides a method for preparing a
compound according to Scheme 3, below:
##STR00010##
[0088] A further embodiment provides a method for preparing a
compound according to Scheme 4, below:
##STR00011##
[0089] For pharmaceutical use, the compounds disclosed are, for
instance, administered orally, sublingually, rectally, nasally,
vaginally, topically (including the use of a patch or other
transdermal delivery device), by pulmonary route by use of an
aerosol, or parenterally, including, for example, intramuscularly,
subcutaneously, intraperitoneally, intra-arterially, intravenously
or intrathecally. Administration can be by means of a pump for
periodic or continuous delivery. The compounds disclosed are
administered alone, or are combined with a
pharmaceutically-acceptable carrier or excipient according to
standard pharmaceutical practice. For the oral mode of
administration, the compounds disclosed are used in the form of
tablets, capsules, lozenges, chewing gum, troches, powders, syrups,
elixirs, aqueous solutions and suspensions, and the like. In the
case of tablets, carriers that are used include lactose, sodium
citrate and salts of phosphoric acid. Various disintegrants such as
starch, and lubricating agents such as magnesium stearate and talc,
are commonly used in tablets. For oral administration in capsule
form, useful diluents are lactose and high molecular weight
polyethylene glycols. If desired, certain sweetening and/or
flavoring agents are added. For parenteral administration, sterile
solutions of the compounds of the invention are usually prepared,
and the pHs of the solutions are suitably adjusted and buffered.
For intravenous use, the total concentration of solutes should be
controlled to render the preparation isotonic. For ocular
administration, ointments or droppablc liquids may be delivered by
ocular delivery systems known to the art such as applicators or eye
droppers. Such compositions can include mucomimetics such as
hyaluronic acid, chondroitin sulfate, hydroxypropyl methylcellulose
or polyvinyl alcohol, preservatives such as sorbic acid, EDTA or
benzylchromium chloride, and the usual quantities of diluents
and/or carriers. For pulmonary administration, diluents and/or
carriers will be selected to be appropriate to allow the formation
of an aerosol.
[0090] Suppository forms of the compounds disclosed are useful for
vaginal, urethral and rectal administrations. Such suppositories
will generally be constructed of a mixture of substances that is
solid at room temperature but melts at body temperature. The
substances commonly used to create such vehicles include theobroma
oil, glycerinated gelatin, hydrogenated vegetable oils, mixtures of
polyethylene glycols of various molecular weight and fatty acid
esters of polyethylene glycol. See, Remington's Pharmaceutical
Sciences, 16th Ed., Mack Publishing, Easton, Pa., 1980, pp.
1530-1533 for further discussion of suppository dosage forms.
Analogous gels or creams can be used for vaginal, urethral and
rectal administrations.
[0091] Numerous administration vehicles will be apparent to those
of ordinary skill in the art, including without limitation slow
release formulations, liposomal formulations and polymeric
matrices.
[0092] Examples of pharmaceutically acceptable acid addition salts
for use with the compounds disclosed include those derived from
mineral acids, such as hydrochloric, hydrobromic, phosphoric,
metaphosphoric, nitric and sulfuric acids, and organic acids, such
as tartaric, acetic, citric, malic, lactic, fumaric, benzoic,
glycolic, gluconic, succinic, p-toluenesulphonic and arylsulphonic
acids, for example. Examples of pharmaceutically acceptable base
addition salts for use with the compounds disclosed include those
derived from non-toxic metals such as sodium or potassium, ammonium
salts and organoamino salts such as triethylamine salts. Numerous
appropriate such salts will be known to those of ordinary
skill.
[0093] The physician or other health care professional can select
the appropriate dose and treatment regimen based on the subject's
weight, age, and physical condition. Dosages will generally be
selected to maintain a serum level of compounds of the invention
between about 0.01 .mu.g/cc and about 1000 .mu.g/cc, preferably
between about 0.1 .mu.g/cc and about 100 .mu.g/cc. For parenteral
administration, an alternative measure of an exemplary amount is
from about 0.001 mg/kg to about 10 mg/kg (alternatively, from about
0.01 mg/kg to about 10 mg/kg), such as from about 0.01 mg/kg to
about 1 mg/kg (from about 0.1 mg/kg to about 1 mg/kg), will be
administered. For oral administrations, an alternative measure of
administration amount is from about 0.001 mg/kg to about 10 mg/kg
(from about 0.1 mg/kg to about 10 mg/kg), such as from about 0.01
mg/kg to about 1 mg/kg (from about 0.1 mg/kg to about 1 mg/kg). For
administrations in suppository form, an alternative measure of
administration amount is from about 0.1 mg/kg to about 10 mg/kg,
such as from about 0.1 mg/kg to about 1 mg/kg.
EXAMPLES
[0094] All starting materials are commercially available or earlier
described in the literature.
[0095] The .sup.1H and .sup.13C NMR spectra were recorded either on
Bruker 300, Bruker DPX400 or Varian +400 spectrometers operating at
300, 400 and 400 MHz for .sup.1H NMR respectively, using TMS or the
residual solvent signal as reference, in deuterated chloroform as
solvent unless otherwise indicated. All reported chemical shifts
are in ppm on the delta-scale, and the fine splitting of the
signals as appearing in the recordings (s: singlet, br s: broad
singlet, d: doublet, t: triplet, q: quartet, m: multiplet). Unless
otherwise indicated, in the tables below .sup.1H NMR data was
obtained at 300 MHz, using CDCl.sub.3 as the solvent.
[0096] Purification of products were also done using Chem Elut
Extraction Columns (Varian, cat #1219-8002), Mega BE-SI (Bond Elut
Silica) SPE Columns (Varian, cat #12256018; 12256026; 12256034), or
by flash chromatography in silica-filled glass columns.
Example 1.1
Methyl 2-(dibenzylamino)-3-hydroxypropanoate
##STR00012##
[0098] Methyl serine hydrochloride (15 g, 0.096 mol) was stirred
with potassium carbonate (66.6 g, 0.482 mol) and benzyl bromide
(41.2 g, 0.24 mol) in acetonitrile (240 mL) at room temperature for
24 hours. The reaction mixture was filtered and washed with ethyl
acetate. The filtrate was concentrated with silica gel. The product
was purified by column chromatography, eluting with 5-20% ethyl
acetate in hexanes, to give methyl
2-(dibenzylamino)-3-hydroxypropanoate (27 g, 93.5%) as a
pale-yellow sticky oil. .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.25-7.40 (m, 10H), 3.94 (d, 2H), 3.83 (s, 3H), 3.79
(m, 2H), 3.71 (d, 2H), 3.60 (t, 1H) and 2.62 (t, 1H).
Example 2.1
Methyl 2-dibenzylamino-3-difluoromethoxy-propionate
##STR00013##
[0100] To an acetonitrile solution of methyl
2-(dibenzylamino)-3-hydroxypropanoate (23 g, 76.8 mmol) and sodium
sulfate (3.9 g, 27.4 mmol) at 40.degree. C.,
difluoro(fluorosulfonyl)acetic acid (25 g, 140 mmol) was added
dropwise for 1.5 hrs. The reaction mixture was concentrated to
dryness and the residue was mixed with silica gel in ethyl acetate,
then again concentrated to dryness. The product was purified by
column chromatography, eluting with 3-4% ethyl acetate in hexanes,
to give methyl 2-dibenzylamino-3-difluoromethoxy-propionate (1.3 g,
4.8%) as a colorless oil. .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.20-7.40 (m, 10H), 6.18 (bt, 1H), 4.05-4.24 (m, 2H),
3.90 (d, 2H), 3.83 (s, 3H) and 3.64-3.71 (m, 3H).
Example 3.1
2-(Dibenzylamino)-3-(difluoromethoxy) propanoic acid
##STR00014##
[0102] Methyl 2-dibenzylamino-3-difluoromethoxy-propionate (1.2 g,
3.43 mmol) was stirred with 1N LiOH (10.3 mL, 10.3 mmol) in THF (40
mL) at 50.degree. C. for 2 hours and then stirred at room
temperature overnight. The reaction mixture was diluted with ethyl
acetate and acidified with 1N HCl. The organic layer was dried with
sodium sulfate and concentrated with silica gel. The product was
purified by column chromatography, eluting with 10-50% ethyl
acetate in hexanes, to give 2-(dibenzylamino)-3-(difluoromethoxy)
propanoic acid (730 mg, 63.5%) as a white solid. .sup.1H NMR (300
MHz, CDCl.sub.3): (ppm) 7.26-7.42 (m, 10H), 6.29 (bt, 1H), 4.45
(dd, 1H), 4.28 (dd, 1H), 3.94 (q, 4H) and 3.85 (m, 1H).
Example 4.1
2-(Dibenzylamino)-3-(difluoromethoxy)-N-benzylpropanamide
##STR00015##
[0104] To a solution of 2-(dibenzylamino)-3-(difluoromethoxy)
propanoic acid (335.4 mg, 1 mmol) and triethylamine (404.8 mg, 4
mmol) in THF (5 mL) at -5.degree. C., isobutyl chloroformate (143.5
mg, 1.05 mmol) was added dropwise. After 20 minutes, benzylamine
hydrochloride (215.4 mg, 1.5 mmol) was added and the reaction
mixture was allowed to warm up to room temperature. The mixture was
then diluted with ethyl acetate and washed with water, 0.5N HCl and
Brine. The organic layer was dried over magnesium sulphate,
concentrated with silica gel and purified by to column
chromatography, eluting with 10-20% ethyl acetate in hexanes to
give 2-(dibenzylamino)-3-(difluoromethoxy)-N-benzylpropanamide (367
mg, 86.5%) as a white solid. .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.56 (t, 1H), 7.17-7.34 (m, 15H), 6.35 (wt, 1H), 4.60
(dd, 1H), 4.43 (m, 3H), 3.95 (d, 2H), 3.68 (d, 2H) and 3.67 (m,
1H).
Example 5.1
2-Dibenzylamino-3-difluoromethoxy-N-(4-fluorobenzyl)propionamide
##STR00016##
[0106] To a solution of 2-(dibenzylamino)-3-(difluoromethoxy)
propanoic acid (335.4 mg, 1 mmol) and triethylamine (404.8 mg, 4
mmol) in THF (5 mL) at -5.degree. C., isobutyl chloroformate (143.5
mg, 1.05 mmol) was added dropwise. After 20 minutes,
4-fluorobenzylamine (137.5 mg, 1.1 mmol) was added and the reaction
mixture was allowed to warm up to room temperature. The mixture
then was diluted with ethyl acetate and washed with water, 0.5 N
HCl and Brine. The organic layer was dried over magnesium sulphate,
concentrated with silica gel and purified by column chromatography,
eluting with 10-20% ethyl acetate in hexanes, to give
2-dibenzylamino-3-difluoromethoxy-N-(4-fluorobenzyl) propionamide
(395 mg, 89.2%) as a colorless oil. .sup.1H NMR (300 MHz,
CDCl.sub.3): (ppm) 7.56 (t, 1H), 6.98-7.32 (m, 14H), 6.35 (wt, 1H),
4.61 (dd, 1H), 4.41 (m, 3H), 3.86 (d, 2H), 3.70 (d, 2H) and 3.68
(m, 1H).
Example 6.1
2-Dibenzylamino-N-(3,4-difluoro-benzyl)-3-difluoromethoxy-propion-amide
##STR00017##
[0108] To a solution of 2-(dibenzylamino)-3-(difluoromethoxy)
propanoic acid (280 mg, 0.835 mmol) and triethylamine (338 mg, 3.34
mmol) in THF (5 mL) at -5.degree. C., isobutyl chloroformate (119.8
mg, 0.876 mmol) was added dropwise. After 20 minutes,
3,4-difluorobenzylamine (131.3 mg, 0.919 mmol) was added and the
reaction mixture allowed to warm up to 0.degree. C. for another
hour. The mixture was then diluted with ethyl acetate and washed
with water, 0.5 N HCl and Brine. The organic layer was dried over
magnesium sulphate, concentrated with silica gel and purified by
column chromatography, eluting with 10-20% ethyl acetate in
hexanes, to give
2-dibenzylamino-N-(3,4-difluoro-benzyl)-3-difluoromethoxy-propion-
amide (298 mg, 77.5%) as a colorless oil. .sup.1H NMR (300 MHz,
CDCl.sub.3): .delta.(ppm) 7.56 (t, 1H), 6.82-7.38 (m, 13H), 6.60
(wt, 1H), 4.58 (dd, 1H), 4.37 (m, 3H), 3.90 (d, 21-1), 3.73 (d, 2H)
and 3.70 (m, 1H).
Example 7.1
2-Amino-N-benzyl-3-(difluoromethoxy)propanamide
##STR00018##
[0110] 2-(Dibenzylamino)-3-(difluoromethoxy)-N-benzylpropanamide
(362 mg, 0.863 mmol) was stirred with 10% Pd(OH).sub.2 (200 mg) in
ethanol under H.sub.2 overnight. The reaction mixture was filtered
and concentrated to give
2-amino-N-benzyl-3-(difluoromethoxy)propanamide (195 mg, 93.6%) as
a colorless oil. .sup.1H NMR (300 MHz, CDCl.sub.3): .delta.(ppm)
7.83 (t, 1H), 7.25-7.40 (m, 5H), 6.27 (wt, 1H), 4.49 (d, 2H), 4.19
(d, 2H) and 3.68 (m, 1H).
Example 8.1
2-Amino-3-difluoromethoxy-N-(4-fluorobenzyl) propionamide
##STR00019##
[0112]
2-Dibenzylamino-3-difluoromethoxy-N-(4-fluorobenzyl)propionamide
(390 mg, 0.881 mmol) was stirred with 10% Pd(OH).sub.2 (200 mg) in
ethanol under H.sub.2 overnight. The reaction mixture was filtered
and concentrated to give
2-mino-3-difluoromethoxy-N-(4-fluorobenzyl)propionamide (200 mg,
86.5%) as a colorless oil. .sup.1H NMR (300 MHz, DMSO-d6):
.delta.(ppm) 8.88 (t, 1H), 7.31 (dd, 2H), 7.16 (t, 2H), 6.73 (wt,
1H), 4.2 (d, 2H), 4.10 (m, 2H) and 3.89 (m, 1H).
Example 9.1
2-(Acetylamino)-N-benzyl-3-(difluoromethoxy)propanamide
##STR00020##
[0114] To a solution of
2-amino-N-benzyl-3-(difluoromethoxy)propanamide (195 mg, 0.798
mmol) and triethylamine (322 mg, 3.19 mmol) in THF (5 mL), acetic
hydride (98.5 mg, 0.958 mmol) was added. The reaction mixture was
stirred at room temperature for an hour, diluted with ethyl acetate
and washed with water. The organic layer was concentrated with
silica gel and purified by column chromatography, eluting with
50-100% ethyl acetate in hexanes. The product was triturated with
diethyl ether to give
2-(acetylamino)-N-benzyl-3-(difluoromethoxy)propanamide (135 mg,
59%) as a white solid, MP: 173.3.degree. C. .sup.1H NMR (300 MHz,
CDCl.sub.3): (ppm) 7.25-7.39 (m, 5H), 6.68 (w, 1H), 6.42 (d, 1H),
6.24 (wt, 1H), 4.73 (m, 1H), 4.48 (d, 2H), 4.24 (dd, 1H), 4.01 (dd,
1H) and 2.05 (s, 3H).
Example 10.1
2-(Acetylamino)-3-(difluoromethoxy)-N-(4-fluorobenzyl)propan-amide
##STR00021##
[0116] To a solution of
2-amino-3-difluoromethoxy-N-(4-fluorobenzyl)propionamide (200 mg,
0.762 mmol) and triethylamine (293 mg, 2.9 mmol) in THF (5 mL),
acetic hydride (93 mg, 0.915 mmol) was added. The reaction mixture
was stirred at room temperature for three hours, diluted with ethyl
acetate, and washed with water. The organic layer was concentrated
with silica gel and purified by column chromatography with 50-100%
ethyl acetate in hexanes. The product was triturated with diethyl
ether to give
2-(acetylamino)-N-benzyl-3-(difluoromethoxy)propanamide (140 mg,
60.3%) as a white solid, MP: 130.8.degree. C. .sup.1H NMR (300 MHz,
CDCl.sub.3): (ppm) 7.24 (dd, 2H), 7.03 (t, 2H), 6.73 (w, 1H), 6.41
(d, 1H), 6.24 (wt, 1H), 4.71 (m, 1H), 4.44 (d, 2H), 4.24 (dd, 1H),
4.01 (dd, 1H) and 2.05 (s, 3H).
Example 11.1
2-(Acetylamino)-N-(3,4-difluorobenzyl)-3-(difluoromethoxy)
propan-amide
##STR00022##
[0118]
2-dibenzylamino-N-(3,4-difluoro-benzyl)-3-difluoromethoxy-propionam-
ide (298 mg, 0.645 mmol) was stirred with 10% Pd(OH).sub.2 (200 mg)
in ethanol under H.sub.2 overnight. The reaction mixture was
filtered and concentrated. The residue was mixed with triethylamine
(254 mg, 2.5 mmol) in dichloromethane (2 mL) and treated with
acetic anhydride (85 .mu.L) at room temperature for 2 hours. The
reaction mixture was diluted with dichloromethane and washed with
water. The organic layer was concentrated with silica gel and
purified by column chromatography, eluting with 30-100% ethyl
acetate in hexanes. The product was triturated with diethyl ether
to give
2-amino-N-(3,4-difluorobenzyl)-3-(difluoromethoxy)propanamide (125
mg, 60%) as a white solid, MP: 146.degree. C. .sup.1H NMR (300 MHz,
CDCl.sub.3): .delta.(ppm) 6.92-7.16 (m, 4H), 6.47 (d, 1H), 6.25
(wt, 1H), 4.75 (m, 1H), 4.41 (m, 2H), 4.22 (dd, 1H), 4.02 (dd, 1H)
and 2.05 (s, 3H).
Example 12.1
Benzyl (2R)-2-(dibenzylamino)-3-hydroxypropanoate
##STR00023##
[0120] D-serine (10.5 g, 0.1 mol) was stirred with potassium
carbonate (69 g, 0.5 mol), benzyl bromide (64.8 g, 0.375 mol) and
water (10 mL) in acetonitrile (250 mL) at 55.degree. C. for 24
hours. The reaction mixture was filtered and washed with ethyl
acetate. The filtrate was concentrated with silica gel. The product
was purified by column chromatography, eluting with 5-20% ethyl
acetate in hexanes to give benzyl
(2R)-2-(dibenzylamino)-3-hydroxypropanoate (33.36 g, 88%) as a
pale-yellow sticky oil. .sup.1H NMR (300 MHz, CDCl.sub.3): (ppm)
7.20-7.44 (m, 15H), 5.27 (q, 2H), 3.91 (d, 2H), 3.80 (m, 2H), 3.67
(d, 2H), 3.63 (m, 1H) and 2.52 (dd, 1H).
Example 13.1
Benzyl (2R)-2-(dibenzylamino)-3-difluoromethoxy-propionate
##STR00024##
[0122] To a mixture of Benzyl
(2R)-2-(dibenzylamino)-3-hydroxypropanoate (22.2 g, 59.2 mmol) and
sodium sulfate (2.0 g, 14 mmol) in acetonitrile (200 mL) at
40.degree. C., difluoro(fluorosulfonyl)acetic acid (10.5 g, 59.2
mmol) was added dropwise for 1.5 hrs. The reaction mixture was
concentrated to dryness. The residue was mixed with ethyl acetate
and silica gel, then concentrated again and purified by column
chromatography, eluting with 1.5-2.5% ethyl acetate in hexanes to
give benzyl (2R) 2-dibenzylamino-3-difluoromethoxy-propionate
(3.375 g, 13.4%) as a colorless oil. .sup.1H NMR (300 MHz,
CDCl.sub.3): (ppm) 7.20-7.40 (m, 15H), 6.17 (wt, 1H), 5.27 (q, 2H),
4.22 (dd, 1H), 4.10 (dd, 1H), 3.88 (d, 2H), 3.74 (t, 1H) and 3.65
(d, 2H).
Example 14.1
(2R)-2-Amino-3-(difluoromethoxy) propanoic acid
##STR00025##
[0124] Benzyl (2R) 2-dibenzylamino-3-difluoromethoxy-propionate
(3.1 g, 6.28 mmol) was stirred with Pd(OH).sub.2 in methanol under
H.sub.2 overnight. The reaction mixture was filtered and the
filtrate concentrated to dryness, then triturated with diethyl
ether to give (2R)-2-amino-3-(difluoromethoxy)propanoic acid (773
mg, 68.4%) as a white solid. .sup.1H NMR (300 MHz, MeOD): (ppm)
6.49 (wt, 1H), 4.33 (dd, 1H), 4.22 (dd, 1H), and 3.88 (dd, 1H).
Example 15.1
(2R)-2-[(tert-Butoxycarbonyl)amino]-3-(difluoromethoxy) propanoic
acid
##STR00026##
[0126] (2R)-2-Amino-3-(difluoromethoxy)propanoic acid (380 mg, 2.45
mmol) was stirred with sodium bicarbonate (411.6 mg. 4.90 mmol) and
di-tert-butyl dicarbonate (902 mg, 3.68 mmol) in water (6 mL) and
THF (2 mL) at room temperature overnight. The reaction mixture was
diluted with water and extracted with ether to remove excess
di-tert-butyl dicarbonate. The aqueous layer was acidified with 1N
HCl to pH 2 and extracted with ethyl acetate, dried over magnesium
sulphate and concentrated to give
(2R)-2-[(tert-butoxycarbonyl)amino]-3-(difluoromethoxy) propanoic
acid (515 mg, 82.3%) as a colorless sticky oil. .sup.1H NMR (300
MHz, CDCl.sub.3): .delta.(ppm) 6.23 (wt, 1H), 5.35 (d, 1H), 4.60
(m, 1H), 4.33 (m, 1H), 4.17 (m, 1H) and 1.51 (s, 9H).
Example 16.1
tert-Butyl
{(1R)-2-(benzylamino)-1-[(difluoromethoxy)methyl]-2-oxoethyl}ca-
rbamate
##STR00027##
[0128] To a solution of
(2R)-2-[(tert-butoxycarbonyl)amino]-3-(difluoromethoxy) propanoic
acid (510 mg, 2.0 mmol) and triethylamine (607.1 mg, 6 mmol) in THF
(10 mL) at -78.degree. C., isobutyl chloroformate (348 mg, 2.55
mmol) was added dropwise. After 30 minutes, benzylamine (321.5 mg,
3.0 mmol) was added and the reaction mixture allowed to warm up to
room temperature. The mixture then was diluted with ethyl acetate
and washed with water, 0.5N HCl and Brine. The organic layer was
dried over magnesium sulphate, concentrated, and triturated with
ether-hexanes (1:3) to give tert-butyl
{(1R)-2-(benzylamino)-1-[(difluoromethoxy)methyl]-2-oxoethyl}carbamate
(345 mg, 50%) as a white solid. .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.40-7.80 (m, 511), 6.60 (t, 1H), 6.22 (wt, 1H), 5.25
(w, 1H), 4.32-4.55 (m, 4H), 4.05 (dd, 1H) and 1.48 (s, 911).
Example 17.1
tert-Butyl
{(1R)-1-[(difluoromethoxy)methyl]-2-[(4-fluorobenzyl)amino]-2-o-
xoethyl}carbamate
##STR00028##
[0130] To a solution of
(2R)-2-[(tert-butoxycarbonyl)amino]-3-(difluoromethoxy) propanoic
acid (780 mg, 3.05 mmol) and triethylamine (924 mg, 9.15 mmol) in
THF (15 mL) at -78.degree. C., isobutyl chloroformate (417.7 mg,
3.05 mmol) was added dropwise. After 30 minutes, (4-fluorobenzyl)
amine (458 mg, 3.0 mmol) was added and the reaction mixture was
allowed to warm up to room temperature. The mixture was then
diluted with ethyl acetate and washed with water, 0.5N HCl and
Brine. The organic layer was dried over magnesium sulphate,
concentrated, and triturated with hexanes (1:3) to give tert-butyl
{(1R)-1-[(difluoromethoxy)
methyl]-2-[(4-fluorobenzyl)amino]-2-oxoethyl}carbamate (870 mg,
78.7%) as a white solid. .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.23 (dd, 2H), 7.03 (t, 2H), 6.60 (b, 1H), 6.23 (wt,
1H), 5.24 (w, 1H), 4.3-4.51 (m, 4H), 4.02 (dd, 1H) and 1.45 (s,
9H).
Example 18.1
tert-butyl
{(1R)-2-[(4-chlorobenzyl)amino]-1-[(difluoromethoxy)methyl]-2-o-
xoethyl}carbamate
##STR00029##
[0132] To a solution of (2R)-2-Amino-3-(difluoromethoxy) propanoic
acid (500 mg, 1.96 mmol) in THF (15 mL) at -78.degree. C.,
4-methylmorpholine (198 mg, 1.96 mmol) followed by isobutyl
chloroformate (272 mg, 1.96 mmol) were added dropwise.
(4-Chlorobenzyl) amine (332 mg, 2.35 mmol) was then added and the
reaction mixture was allowed to warm up to room temperature. The
mixture was then diluted with ethyl acetate and washed with water
and brine. The organic layer was dried over magnesium sulphate,
concentrated, and purified by column chromatography to yield
tert-butyl {(1R)-2-[(4-chlorobenzyl)amino]-1
[(difluoromethoxy)methyl]-2-oxoethyl}carbamate.
[0133] (652 mg, 88%). .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.36 (d, 2H), 7.20 (d, 2H), 6.64 (broad, 1H), 6.23
(wt, 1H), 5.24 (broad, 1H), 4.50 (d, 211), 4.41 (broad, 1H), 4.32
(m, 1H), 4.03 (m, 1H), 1.45 (s, 9H).
[0134] In a similar manner the following compounds were
synthesized:
TABLE-US-00001 Example Structure Name Yield 18.2 ##STR00030##
tert-butyl {(1R)-1- [(difluoromethoxy) methyl]-2-[(3-fluoro- benzyl
amino]-2- oxoethyl} carbamate 623 mg, 88% yield NMR .sup.1H NMR
(300 MHz, CDCl.sub.3): .delta.(ppm) 7.32 (m, 1H), 7.00 (m, 3H) 6.65
(broad, 1H), 6.24 (wt, 1H), 5.23 (broad, 1H), 4.49 (broad, 2H),
4.43 (broad, 1H), 4.35 (m, 1H), 4.05 (m, 1H), 1..46 (s, 9H) 18.3
##STR00031## tert-butyl {(1R)-1- [(difluorometh-
oxy)methyl]-2-[(3,4- difluorobenzyl)amino]- 2-oxoethyl} carbamate
514 mg, 86% yield NMR .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.16 (m, 2H), 7.00 (broad, 1H), 6.67 (broad, 1H), 6.24
(wt, 1H), 5.22 (broad, 1H), 4.46 (broad, 2H), 4.40 (broad, 1H),
4.34 (m, 1H), 4.03 (m, 1H), 1.46 (s, 9H) 18.4 ##STR00032##
Tert-butyl {(1R)-1- [(difluorometh- oxy)methyl]-2-oxo-2-
[(2-thienylmethyl) amino]ethyl} carbamate 559 mg, 82% yield NMR
.sup.1H NMR (300 MHz, CDCl.sub.3): .delta.(ppm) 7.23 (d, 1H), 6.69
(m, 2H) 6.62 (broad, 1H), 6.23 (wt, 1H), 5.22 (broad, 1H), 6.52
(broad, 1H), 4.40 (broad, 1H), 4.32 (m, 1H), 4.02 (m, 1H), 1.45 (s,
9H) 18.5 ##STR00033## tert-butyl {(1R)-1- [(difluorometh-
oxy)methyl]-2-[(4- methyl-benzyl)amino]-2- oxoethyl} carbamate 528
mg, 98% yield NMR .sup.1H NMR (300 MHz, CDCl.sub.3): .delta.(ppm)
7.18 (s, 4H), 6.51 (broad, 1H), 6.24 (wt, 1H), 5.21 (broad, 1H),
4.45 (broad, 2H), 4.40 (broad, 1H), 4.33 (m, 2H), 4.02 (m, 1H),
2.34 (s, 3H), 1.45 (s, 9H) 18.6 ##STR00034## tert-butyl {(1R)-2
[(3-chlorobenzyl) aminol-1-[(difluoro- methoxy)methyl]-2- oxoethyl}
carbamate 354 mg, 95% yield NMR .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) . 7.26 (m, 3H), 7.15 (m, 1H) < 6.65 (broad, 1H),
6.26 (wt, 1H), 5.21 (broad, 1H), 4.48 (broad t, 2H), 4.42 (broad,
1H), 4.35 (m, 1H), 4.04 (m, 1H), 1.46 (s, 9H) 18.7 ##STR00035##
tert-butyl {(1R)-2- [(3-methylbenzyl) amino]-]-[(difluoro-
methoxy)methyl]-2- oxoethyl} carbamate 339 mg, 97% yield NMR
.sup.1H NMR (300 MHz, CDCl.sub.3): .delta.(ppm) . 7.23 (t, 1H),
7.08 (t, 3H) 6.57 (broad, 1H), 6.23 (wt, 1H), 5.27 (broad, 1H),
4.44 (d, 2H), 4.41 (broad, 1H), 4.32 (m, 1H), 4.03 (m, 1H), 2.34
(s, 3H), 1.45 (s, 9H) 18.8 ##STR00036## tert-butyl {(1R)-1
[(difluorometh- oxy)methyl]-2-oxo-2- [(3-thienylmethyl)
amino]ethyl} carbamate 330 mg, 96% yield NMR .sup.1H NMR (300 MHz,
CDCl.sub.3): .delta.(ppm) 7.31 (m, 1H), 7.15 (s, 1H), 7.01 (d, 1H),
6.56 (broad, 1H), 6.24 (wt, 1H), 5.21 (broad, 1H), 4.49 (d, 1H),
4.40 (broad, 1H), 4.33 (m, 1H), 4.03 (m, 1H), 1.46 (s, 9H)
Example 19.1
(2R)-2-(Acetylamino)-N-benzyl-3-(difluoromethoxy)propanamide
##STR00037##
[0136] Method A:
[0137] Tert-Butyl
{(1R)-2-(benzylamino)-1-[(difluoromethoxy)methyl]-2-oxoethyl}carbamate
(340 mg, 0.987 mmol) was stirred with trifluoroacetic acid (2.25
mL) and dichloromethane (2.5 mL) in an ice bath for an hour. The
reaction mixture was concentrated, stirred with acetic
anhydride-pyridine (1:1, 5.8 mL) at room temperature for 30 minutes
and then diluted with ethyl acetate, washed with saturated sodium
bicarbonate, brine, 0.5N HCl and brine again. The organic layer was
dried, concentrated, and triturated with diethyl ether to give
(2R)-2-(acetylamino)-N-benzyl-3-(difluoromethoxy)propanamide (230.5
mg, 77.2%) as a white solid. Mp: 186.9.degree. C. .sup.1H NMR (300
MHz, DMSO-d6): (ppm) 8.60 (t, 1H), 8.30 (d, 1H), 7.28-7.45 (m, 5H),
6.67 (wt, 1H), 4.58 (m, 1H), 4.40 (d, 2H), 3.98 (d, 2H) and 1.88
(s, 3H).
[0138] Method B:
[0139] To a solution of
(2R)-2-[(tert-butoxycarbonyl)amino]-3-(difluoromethoxy) propanoic
acid (197 mg, 1.0 mmol) and triethylamine (303 mg, 3 mmol) in THF
(10 mL) at -78.degree. C., isobutyl chloroformate (174 mg, 1.28
mmol) was added dropwise. After 30 minutes, benzylamine (161 mg,
1.5 mmol) was added and the reaction mixture was allowed to warm up
to room temperature. The mixture then was diluted with ethyl
acetate and washed with water, 0.5N HCl and Brine. The organic
layer was dried over magnesium sulphate, concentrated, and
triturated with ether-hexanes (1:3) to give
(2R)-2-(acetylamino)-N-benzyl-3-(difluoromethoxy)propanamide (48
mg, 16.7%) as a white solid. .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.25-7.39 (m, 5H), 6.68 (w, 1H), 6.42 (d, 1H), 6.24
(wt, 1H), 4.73 (m, 1H), 4.48 (d, 2H), 4.24 (dd, 1H), 4.01 (dd, 1H)
and 2.05 (s, 3H).
Example 20.1
(2R)-2-(Acetylamino)-3-(difluoromethoxy)-N-(4-fluorobenzyl)
propanamide
##STR00038##
[0141] Tert-Butyl
{(1R)-1-[(difluoromethoxy)methyl]-2-[(4-fluorobenzyl)amino]-2-oxoethyl}ca-
rbamate (400 mg, 1.1 mmol) was stirred with trifluoroacetic acid
(1.5 mL) and dichloromethane (2.5 mL) in an ice bath for an hour.
The reaction mixture was concentrated, mixed with acetic
anhydride-pyridine (1:1, 6 mL) at room temperature for 30 minutes
and then diluted with ethyl acetate, washed with saturated sodium
bicarbonate, brine, 0.5N HCl and brine again. The organic layer was
dried, concentrated, and triturated with diethyl ether to give
(2R)-2-(acetylamino)-3-(difluoromethoxy)-N-(4-fluorobenzyl)propanamide
(220 mg, 65.7%) as a white solid. Mp: 162.7.degree. C. .sup.1H NMR
(300 MHz, CDCl.sub.3): (ppm) 7.24 (dd, 2H), 7.03 (t, 2H), 6.78 (w,
1H), 6.35 (d, 1H), 6.24 (wt, 1H), 4.71 (m, 1H), 4.44 (d, 2H), 4.24
(dd, 1H), 4.01 (dd, 1H) and 2.05 (s, 3H).
Example 21.1
(2R)-2-(Acetylamino)-3-(difluoromethoxy)propanoic acid
##STR00039##
[0143] (2R)-2-Amino-3-(difluoromethoxy)propanoic acid (680 mg, 4.39
mmol) was mixed with sodium bicarbonate (738 mg. 8.78 mmol) and
acetic anhydride (491 mg, 4.82 mmol) in water (10 mL) and dioxane
(10 mL) at 0.degree. C. to room temperature overnight. The reaction
mixture was acidified with 1N HCl to pH 2, concentrated and
extracted with ethyl acetate, and concentrated again to give
(2R)-2-(Acetylamino)-3-(difluoromethoxy) propanoic acid (580 mg,
82.3%) as a colorless sticky oil. .sup.1H NMR (300 MHz,
CDCl.sub.3): (ppm) 6.40 (d, 1H), 6.24 (wt, 1H), 4.88 (m, 1H), 4.36
(dd, 1H), 4.22 (dd, 1H), 2.12 (s, 3H).
Example 22.1
(2R)--N-benzyl-3-(difluoromethoxy)-2-[(methylsulfonyl)amino]propanamide
##STR00040##
[0145] A solution of
(2R)-2-amino-N-benzyl-3-(difluoromethoxy)propanamide (113 mg, 0.46
mmol) in ethyl acetate was cooled in an ice bath. To the cooled
solution was added triethylamine (139 mg, 1.38 mmol) followed by
methanesulfonylchloride (63 mg, 0.55 mmol). The reaction mixture
was stirred for 15 minutes and then quenched with water, extracted
with ethyl acetate and washed with brine. The organic layer was
dried, concentrated and triturated with diethyl ether to give the
product (33 mg, 22%) as a white solid. .sup.1H NMR (300 MHz,
CDCl.sub.3): (ppm) 7.31 (m, 5H), 6.73 (br, 1H), 6.24 (t, 1H), 5.21
(d, 1H), 4.48 (d, 2H), 4.21 (m, 3H), 3.01 (s, 3H)
[0146] In a similar manner the following compound was prepared:
TABLE-US-00002 Example Structure Name Yield 22.2 ##STR00041##
(2R)-3-(difluoro- methoxy)-N-(4- fluorobenzyl)-2- [(methylsulfonyl)
amino] propanamide White solid, 96 mg, 30% NMR .sup.1H NMR (300
MHz, CDCl.sub.3): .delta.(ppm) 7.23 (m, 2H), 7.03 (dd, 2H), 6.76
(br, 1H), 6.22 (t, 1H), 5.16 (dd, 1H), 4.45 (dd, 2H), 4.12 (m, 3H),
2.99 (s, 3H)
Example 23.1
(2R)-2-(acetylamino)-N-(4-chlorobenzyl)-3-(difluoromethoxy)
propanamide
##STR00042##
[0148] A solution of tert-butyl
{(1R)-2-[(4-chlorobenzyl)amino]-1-[(difluoromethoxy)methyl]-2-oxoethyl}ca-
rbamate (652 mg, 1.72 mmol) in dichloromethane (7 mL) was cooled in
an ice-water bath and trifluoroacetic acid (7 mL) was added and
stirred for 30 minutes. The mixture was concentrated and diluted
with water and basified, extracting with ethyl acetate. The organic
extracts were washed with brine, dried over magnesium sulphate and
concentrated to yield the product (444 mg, 92%), which was
dissolved in ethyl acetate and cooled in an ice bath. To the cooled
solution was added triethylamine (242 mg, 2.4 mmol) followed by
acetyl chloride (118 mg, 1.2 mmol). The reaction mixture was
stirred for 15 minutes and then quenched with water, extracted with
ethyl acetate and washed with brine. The organic layer was dried,
concentrated and triturated with diethyl ether to give
(2R)-2-(acetylamino)-N-(4-chlorobenzyl)-3-(difluoromethoxy)propanamide
(446 mg, 87%). .sup.1H NMR (300 MHz, CDCl.sub.3): .delta.(ppm) 8.64
(t, 1H), 8.26 (d, 1H), 7.41 (d, 2H), 7.22 (d, 2H), 6.42 (t, 1H),
4.58 (q, 1H), 4.27 (d, 2H), 3.98 (d, 2H), 1.88 (s, 3H).
[0149] In a similar manner the following compounds were
prepared:
TABLE-US-00003 Example Structure Name Yield 23.2 ##STR00043##
(2R)-2-(acetylamino)- 3-(difluoromethoxy)- N-(3-fluorobenzyl)
propanamide White solid, 422 mg, 86% NMR .sup.1H NMR (300 MHz,
CDCl.sub.3): 8.64 (t, 1H), 8.27 (d, 1H), 7.34 (m, 1H), 7.03 (m,
3H), 6.66 (wt, 1H), 4.56 (m, 1H), 4.32 (d, 2H), 4.00 (d, 2H), 1.89
(s, 3H) 23.3 ##STR00044## (2R)-2-(acetylamino)- N-(3,4-difluoro-
benzyl)-3-(difluoro- methoxy) propanamide White solid, 320 mg, 76%
NMR .sup.1H NMR (300 MHz, DMSO): .delta.(ppm) 8.64 (t, 1H), 8.27
(d, 1H), 7.32 (m, 2H), 7.08 (br, 1H), 6.66 (t, 1H), 4.56 (q, 1H),
4.27 (d, 2H), 3.99 (d, 2H), 1.89 (s, 3H) 23.4 ##STR00045##
(2R)-2-(acetylamino)- 3-(difluoro- methoxy)-N-(2- thienylmethyl)
propanamide White solid, 376 mg, 92% NMR .sup.1H NMR (300 MHz,
DMSO): .delta.(ppm) 8.69 (t, 1H), 8.24 (d, 1H), 7.38 (m, 1H), 6.94
(m, 2H), 6.64 (t, 1H), 4.55 (q, 1H), 4.43 (d, 2H), 3.96 (m, 2H),
1.87 (s, 3H) 23.5 ##STR00046## (2R)-2-(acetylamino)- 3-(difluoro-
methoxy)-N-(4- methylbenzyl) propanamide White solid, 337 mg, 83%
NMR .sup.1H NMR (300 MHz, DMSO): .delta.(ppm) 8.56 (t, 1H), 8.24
(d, 1H), 7.11 (m, 4H), 6.66 (t, 1H), 4.57 (q, 1H), 4.23 (d, 2H),
3.97 (d, 2H), 2.26 (s, 3H), 1.88 (s, 3H) 23.6 ##STR00047##
(2R)-2-(acetylamino)- N-(3-chlorobenzyl)- 3-(difluoro-methoxy)
propanamide White solid, 240 mg, 80% NMR .sup.1H NMR (300 MHz,
DMSO): .delta.(ppm) 8.64 (t, 1H), 8.27 (dd, 1H), 7.31 (m, 3H), 7.2
(dd, 1H), 6.66 (t, 1H), 4.57 (q, 1H), 4.29 (dd, 2H), 4.02 (dd, 2H),
1.89 (s, 3H) 23.7 ##STR00048## (2R)-2-(acetylamino)- 3-(difluoro-
methoxy)-N-(3- methylbenzyl) propanamide White solid, 212 mg, 74%
NMR .sup.1H NMR (300 MHz, DMSO): .delta.(ppm) 8.56 (t, 1H), 8.24
(d, 1H), 7.18 (t, 1H), 7.03 (m, 3H), 6.66 (t, 1H), 4.58 (q, 1H),
4.25 (d, 2H), 3.99 (d, 2H), 2.27 (s, 3H), 1.88 (s, 3H) 23.8
##STR00049## (2R)-2-(acetylamino)- 3-(difluoro- methoxy)-N-(3-
thienylmethyl) propanamide White solid, 195 mg, 78% NMR .sup.1H NMR
(300 MHz, DMSO): .delta.(ppm) 8.55 (t, 1H), 8.23 (d, 1H), 7.46 (dd,
1H), 7.24 (d, 1H), 6.99 (d, 1H), 6.66 (t, 1H), 4.57 (q, 1H), 4.27
(d, 2H), 3.97 (d, 2H), 1.88 (s, 3H)
Example 24.1
2-Acetylamino-N-benzyl-3-difluoromethoxy-propionamide
##STR00050##
[0151] 2-Amino-N-benzyl-3-difluoromethoxy-propionamide (195 mg,
0.80) was mixed with triethylamine (322 mg, 3.19 mmol) in THF (5
mL). Acetic anhydride (98.5 mg, 0.96 mmol) was then added and the
reaction mixture was stirred for 1 hour. The mixture was then
diluted with ethyl acetate and washed with water. The organic layer
was dried and concentrated. The residue was purified by column
chromatography using hexanes:ethyl acetate (50:50 to 0:100). The
isolated product was triturated with diethyl ether to give
2-acetylamino-N-benzyl-3-difluoromethoxy-propionamide (135 mg, 59%)
as a white solid. .sup.1H NMR (300 MHz, CDCl.sub.3): .delta. (ppm)
7.33 (m, 5H), 6.68 (br, 1H), 6.37 (br, 1H), 6.24 (t, 1H), 4.72 (q,
1H), 4.87 (d, 2H), 4.23 (dd, 1H), 4.01 (dd, 1H), 2.05 (s, 3H).
[0152] In a similar manner the following compounds were
prepared:
TABLE-US-00004 Example Structure Name Yield 24.2 ##STR00051##
2-Acetylamino-3- difluoromethoxy-N- (4-fluoro-benzyl)- propionamide
White solid, 140 mg, 60% NMR .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta.(ppm) 7.25 (m, 2H), 7.03 (t, 2H), 6.73 (br, 1H), 6.39 (br,
1H), 6.24 (t, 1H), 4.71 (q, 1H), 4.43 (dd, 2H), 4.25 (dd, 1H), 4.02
(dd, 1H), 2.05 (s, 3H) 24.3 ##STR00052## 2-Acetylamino-N-
(3,4-difluoro-benzyl)- 3-difluoromethoxy- propionamide White solid,
125 mg NMR .sup.1H NMR (300 MHz, CDCl.sub.3): .delta.(ppm) 7.11 (m,
4H), 6.5 (br, 1H), 6.24 (t, 1H), 4.75 (q, 1H), 4.42 (dd, 2H), 4.22
(dd, 1H), 3.49 (dd, 1H), 2.05 (s, 3H)
Example 25.1
Conditioned emotional response assay
[0153] Male, Sprague-Dawley rats of approximate body weight 350-450
g were placed on a restricted food diet (45 min free access per
day) and trained over a 1-2 week period to press a lever for food
reward (45 mg food pellet). Schedule requirements were gradually
increased from a variable interval 5s schedule (VI5) to a final
variable interval 40s schedule (VI40). Test session length was for
a 40 min test period, and test sessions were run 5 days/week. Once
stable response rates were attained, 2 periods of a 2 min light and
tone cue (conditioning stimulus, CS) was introduced into the test
session. The 2 min CS was terminated by a 0.5s unavoidable
footshock of 0.3-0.8 mA intensity (UCS). The first CS-UCS was at
approximately 10 min (range 5-15 min) and the second CS-UCS pairing
at approximately 30 min (range 25-35 min) within the test session.
On drug test days, and occasional training days, footshock was not
delivered. The number of lever presses recorded during the two 2
min CS periods (response A), and the number of lever presses
recorded in the 2 min periods immediately prior to the two CS
periods (response B) were measured and a suppression ratio (SR) was
calculated according to the formula (A/A+B). Thus a SR of 0
reflects no responding during the CS periods, i.e. a complete
suppression of lever pressing for food by the CS, and a SR of 0.5
reflects equivalent responding during both the CS and 2 min period
prior to CS, i.e. no suppression of lever pressing for food by the
CS. Thus in drug untreated animals, SR value was typically 0-0.1
and established anti-anxiety agents such as diazepam increased this
value to 0.4-0.5 (for literature examples see Stanhope and Dourish
(1996) Psychopharmacol. 128: 293-303; Mirza et al (2005)
Psychopharmacol. 180: 159-168). In addition to SR, the total number
of lever presses emitted by the animals over the 40 min test
session was measured.
[0154] Drug testing was conducted according to a repeated measures
design, with each animal receiving each dose of drug treatment or
vehicle control in a balanced design. Typically drug testing was
conducted on Tuesdays and Fridays, with the animals drug untreated
but otherwise run for baseline purposes. In each experiment a
standard dose of diazepam (2 mg/kg i.p) was included as a positive
control.
[0155]
Lacosamide((+)-(2R)-2-(acetylamino)-N-benzyl-3-methoxypropanamide)
demonstrated efficacy in the CER assay by significantly increasing
the SR value from doses 3-30 mg/kg i.p. The magnitude of this
effect was equivalent to diazepam (2 mg/kg i.p). The (S)-enantiomer
of Lacosamide was ineffective in this assay.
[0156] Compounds of Examples 19.1, 20.1, 23.1 were all similarly
active in increasing the SR in a dose-related manner, and to a
level equivalent to diazepam.
[0157] Summary of Data from the Conditioned Emotional Response
Assay of Anxiety.
[0158] Data presented as the mean.+-.SEM from at least 10 rats per
experiment. *p<0.05 compared to vehicle pretreated controls.
TABLE-US-00005 Suppression ratio Total number Compound Dose (SR)
lever press Lacosamide 0 0.08 .+-. 0.03 1068 .+-. 122 3 0.16 .+-.
0.07 1166 .+-. 185 10 0.18 .+-. 0.08 1121 .+-. 138 30 0.36 .+-.
0.07* 727 .+-. 123* (S)-enantiomer of 30 0.06 .+-. 0.03 1403 .+-.
158 Lacosamide Diazepam 2 0.32 .+-. 0.07* 1239 .+-. 183 Example
19.1 0 0.13 .+-. 0.04 957 .+-. 78 3 0.16 .+-. 0.03 1169 .+-. 145 10
0.15 .+-. 0.05 1093 .+-. 169 30 0.38 .+-. 0.04* 724 .+-. 135*
Diazepam 2 0.39 .+-. 0.04* 899 .+-. 146 Example 20.1 0 0.11 .+-.
0.04 1150 .+-. 112 3 0.17 .+-. 0.06 1188 .+-. 95 10 0.28 .+-. 0.07*
1170 .+-. 98 20 0.33 .+-. 0.06* 849 .+-. 78* 30 0.43 .+-. 0.05* 587
.+-. 84* Diazepam 2 0.44 .+-. 0.03* 1015 .+-. 155 Example 23.1 0
0.04 .+-. 0.01 838 .+-. 83 3 0.09 .+-. 0.04 1091 .+-. 169 10 0.17
.+-. 0.04* 1034 .+-. 131 30 0.26 .+-. 0.04* 578 .+-. 79* Diazepam 2
0.44 .+-. 0.03* 1151 .+-. 138
Example 26.1
Marble Burying Assay
[0159] Male, experimentally naive CD-1 mice of body weight range
25-35 g were used in these studies. Following a pretreatment with
test drug or vehicle control the animals were singly placed within
a Perspex chamber of dimension (48 cm.times.28 cm.times.20 cm;
L.times.W.times.H) containing fresh sawdust bedding onto which 22
marbles were evenly spaced on the surface. After a 30 min period,
the mice were removed and the number of marbles that were covered
by at least 2/3rd by sawdust were counted as buried. Typically mice
will bury a significant proportion of the marbles, probably to hide
the potential threat posed by the marbles which represent a novel
stimulus to the animal. A number of anti-anxiety drugs such as
diazepam have been shown to reduce the number of marbles buried by
mice at doses with no obvious effect on general motor function. One
interpretation for this effect is that diazepam reduces the threat
perceived to the animal by the close presence of the marbles
(Broekkamp et al, 1986 Eur. J. Pharmacol. 126: 223-229; Nicolas et
al, 2006 Eur. J. Pharmacol. 547; 106-115). In a separate group of
sex, age and weight matched CD-1 mice, equivalent doses of test
compound were evaluated on motor function using a fixed speed (16
r.p.m) rotorod assay. The best score from 3 attempts was recorded,
with the maximum test duration of 60s. Testing was conducted at 40
min post injection, i.e. approximate mid-point of the
marble-burying assay.
[0160] Drug testing was run according to a between subjects design.
Lacosamide demonstrated efficacy in the marble burying assay by
significantly reducing the number of marbles buried compared to
vehicle pretreated controls at oral doses of 3-30 mg/kg. The
(S)-enantiomer of Lacosamide was ineffective in this assay.
[0161] Compounds of Examples 19.1, 20.1, 23.1 were all similarly
active in decreasing marble burying in a dose-related manner. The
standard anxiolytic drug diazepam also produced a similar profile
in this test.
[0162] Summary of Data from the Mouse Marble Burying Assay of
Anxiety.
[0163] Marble burying data presented as the mean.+-.SEM from at
least 8 mice per treatment. *p<0.05 compared to vehicle
pretreated controls. Rotorod score is the median value from at
least 4 mice per treatment (maximum score=60s). All treatments were
administered by the i.p or oral route.
TABLE-US-00006 Number of marbles Rotorod score Compound Dose buried
(s) Lacosamide 0 17.4 .+-. 0.8 60 3 16.8 .+-. 0.8 60 10 18.0 .+-.
0.7 60 30 12.4 .+-. 1.4* 60 Example 19.1 0 18.0 .+-. 0.8 60 3 17.0
.+-. 1.1 60 10 9.7 .+-. 2.3* 60 30 2.3 .+-. 2.0* 13 Example 20.1 0
15.9 .+-. 0.7 60 3 15.0 .+-. 1.2 60 10 14.9 .+-. 0.9 60 30 10.3
.+-. 1.5* 60 Example 23.1 0 15.3 .+-. 1.0 60 3 15.8 .+-. 0.8 60 10
12.3 .+-. 1.2 60 30 2.0 .+-. 0.7* 60 Diazepam 0 13.1 .+-. 1.3 60
0.3 12.6 .+-. 1.4 60 1 9.4 .+-. 1.7 60 2 2.2 .+-. 1.2* -- 3 2.0
.+-. 0.8* 40
[0164] All publications, including but not limited to patents and
patent applications, cited in this specification are herein
incorporated by reference as if each individual publication were
specifically and individually indicated to be incorporated by
reference herein and as though fully set forth.
[0165] Modifications and improvements of the embodiments
specifically disclosed herein are within the scope of the following
claims. Without further elaboration, it is believed that one
skilled in the area can, using the preceding description, utilize
the present disclosure to its fullest extent. Therefore the
Examples herein are to be construed as merely illustrative and not
a limitation of the scope of the present invention as claimed
hereinafter. The embodiments disclosed, in which an exclusive
property or privilege is claimed are defined as follows.
[0166] It will be obvious to those having skill in the art that
many changes may be made to the details of the above-described
embodiments. The scope of the present invention should, therefore,
be determined only by the following claims.
* * * * *