U.S. patent application number 11/149521 was filed with the patent office on 2005-12-08 for use of r (+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-flurophenyl)-ethyl]-4- piperidinemethanol for the treatment of sleep disorders and process for making pharmaceutical composition.
This patent application is currently assigned to Aventis Pharmaceuticals Inc.. Invention is credited to Hitchcock, Janice M., Mondadori, Cesar, Sorensen, Stephen M..
Application Number | 20050272773 11/149521 |
Document ID | / |
Family ID | 29783167 |
Filed Date | 2005-12-08 |
United States Patent
Application |
20050272773 |
Kind Code |
A1 |
Mondadori, Cesar ; et
al. |
December 8, 2005 |
Use of R
(+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-flurophenyl)-ethyl]-4-
piperidinemethanol for the treatment of sleep disorders and process
for making pharmaceutical composition
Abstract
A process for making a pharmaceutical composition for treating a
variety of sleep disorders comprising an effective amount of
R-(+)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperid-
inemethanol or a pharmaceutically acceptable salt thereof is
disclosed and claimed.
Inventors: |
Mondadori, Cesar; (Basking
Ridge, NJ) ; Sorensen, Stephen M.; (Chester, NJ)
; Hitchcock, Janice M.; (Neshanic Station, NJ) |
Correspondence
Address: |
ROSS J. OEHLER
AVENTIS PHARMACEUTICALS INC.
ROUTE 202-206
MAIL CODE: D303A
BRIDGEWATER
NJ
08807
US
|
Assignee: |
Aventis Pharmaceuticals
Inc.
Bridgewater
NJ
|
Family ID: |
29783167 |
Appl. No.: |
11/149521 |
Filed: |
June 10, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11149521 |
Jun 10, 2005 |
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10609751 |
Jun 30, 2003 |
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6939879 |
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10609751 |
Jun 30, 2003 |
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09886424 |
Jun 21, 2001 |
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6613779 |
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09886424 |
Jun 21, 2001 |
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09382932 |
Aug 25, 1999 |
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6277864 |
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60155214 |
Aug 28, 1998 |
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Current U.S.
Class: |
514/317 |
Current CPC
Class: |
A61K 31/445 20130101;
A61P 25/20 20180101 |
Class at
Publication: |
514/317 |
International
Class: |
A61K 031/445 |
Claims
What is claimed is:
1. A method of manufacturing a pharmaceutical composition for the
treatment of sleep disorders containing
R-(+)-.alpha.-(2,3-dimethoxypheny-
l)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol or a
pharmaceutically acceptable salt thereof, comprising mixing
R-(+)-.alpha.-(2,3-Dimethoxyph-
enyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol or a
pharmaceutically acceptable salt thereof with a pharmaceutically
acceptable carrier.
Description
CROSS REFERENCE TO RELATED CASES
[0001] This application is a continuation of U.S. application Ser.
No. 10/609,751, filed, Jun. 30, 2003, now allowed, which is a
continuation of U.S. application Ser. No. 09/886,424, filed, Jun.
21, 2001, now U.S. Pat. No. 6,613,779 B2, issued Sep. 2, 2003,
which is a continuation of U.S. application Ser. No. 09/382,932,
filed, Aug. 25, 1999, now U.S. Pat. No. 6,277,864 B1, issued Aug.
21, 2001, which claims the benefit of U.S. Provisional Application
No. 60/155,214, filed, Aug. 28, 1998; all of which are incorporated
herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the method of manufacturing
a pharmaceutical composition comprising the
R-(+)-.alpha.-(2,3-Dimethoxyphe-
nyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol or a
pharmaceutically acceptable salt thereof for the treatment of sleep
disorders (insomnia and obstructive sleep apnea).
BACKGROUND OF THE INVENTION
[0003] The compound,
R-(+)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophe-
nyl)ethyl]-4-piperidinemethanol (hereafter referred to as the
"COMPOUND") is a 5HT2a antagonist useful in the treatment of a
variety of disorders. U.S. Pat. No. 5,169,096 claimed compounds
having a generic scope which encompassed the COMPOUND and disclosed
uses of the treatment of anorexia nervosa, variant angina,
Raynaud's phenomenon, coronary vasospasms, prophylactic treatment
of migraine, cardiovascular diseases such as hypertension,
peripheral vascular disease, thrombotic episodes, cardiopulmonary
emergencies and arrythmias, and has anesthetic properties. See also
U.S. Pat. Nos. 4,783,471; 4,912,117; and 5,021,428, which are
divisions of U.S. Pat. No. 5,169,096. See also U.S. Pat. No.
4,877,798 (fibromyalgia), U.S. Pat. No. 4,908,369 (insomnia); U.S.
Pat. No. 5,106,855 (glaucoma); EP 319 962 (anxiety); EP 337 136
(extrapyramidal symptoms). All of the foregoing are incorporated
herein by reference.
[0004] The COMPOUND was then specifically claimed in U.S. Pat. No.
5,134,149 which disclosed uses of antagonizing serotonin at the
5HT2 receptor, treating anxiety, variant angina, anorexia nervosa,
Raynaud's phenomenon, intermittent claudication, coronary or
peripheral vasospasms, fibromyalgia, extrapyramidal symptoms,
arrythmias, thrombotic illness, transient ischemic attacks, drug
abuse, and psychotic illness such as schizophrenia and mania. See
also U.S. Pat. Nos. 5,561,144; 5,700,812; 5,700,813;
5,721,249--divisionals of U.S. Pat. No. 5,134,149--and also U.S.
Pat. No. 5,618,824 (obsessive compulsive disorder) and
PCT/US97/02597 (depressive disorders including major depressive
episode and dysthymia, and bipolar disorder).
[0005] The COMPOUND is highly selective in its activity at the
5HT2a receptor compared to other receptors, and, as such, has
reportedly fewer side effects. It has been shown to have a better
CNS safety index relative to the reference compounds haloperiodol,
clozapine, risperiodone, ritanserin, and amperozide in preclinical
testing. JPET 277:968-981, 1996, incorporated herein by reference.
It has recently been discovered that this COMPOUND is useful in the
treatment of sleep disorders such as insomnia and obstructive sleep
apnea.
[0006] Chronic insomnia among adults in the United States has been
estimated to be present in ten percent of the adult population, and
the annual cost for its treatment is estimated at $10.9 billion.
JAMA 1997; 278: 2170-2177 at 2170. Chronic insomniacs report
elevated levels of stress, anxiety, depression and medical
illnesses. The most common class of medications for treating
insomnia are the benzodiazepines, but the adverse effect profile of
benzodiazepines include daytime sedation, diminished motor
coordination, and cognitive impairments. Furthermore, the National
Institutes of Health Consensus conference on Sleeping Pills and
Insomnia in 1984 has developed guidelines discouraging the use of
such sedative hypnotics beyond 4-6 weeks because of concerns raised
over drug misuse, dependency, withdrawal and rebound insomnia. JAMA
1997; 278: 2170-2177 at 2170. Therefore, it is desirable to have a
pharmacological agent for the treatment of insomnia which is more
effective and/or has fewer side effects that those currently
used.
[0007] The prevalence of obstructive sleep apnea is estimated to be
approximately 1-10% in the adult population, but may be higher in
elderly individuals. DIAGNOSTIC AND STATISTICAL MANUAL OF MENTAL
DISORDERS 4.sup.th ed., American Psychiatric Association,
Washington D.C. Preliminary evidence suggests that having
obstructive sleep apnea may contribute to increased susceptibility
to cardiovascular complications such as hypertension, cardiac
arrhythmias, stroke, and myocardial infarction. Excessive daytime
sleepiness is also a major complication.
[0008] Currently, the therapies used to treat obstructive sleep
apnea include weight loss for the obese patient, nasal-continuous
positive airway pressure (a facemask used at night which produces a
positive pressure within the upper airway), pharyngeal surgery and
the administration of a variety of pharmacologic agents which have
not been proven to be entirely successful. Chest 109 (5):1346-1358
(May 1996) entitled Treatment of Obstructive Sleep Apnea, a Review,
hereby incorporated by reference. These agents include
acetazolamide, medroxyprogesterone, opioid antagonists, nicotine,
angiotensin-converting enzyme inhibitors and psychotropic agents
(including those that prevent the reuptake of biogenic amines such
as norepinephreine, dopamine and serotonin). Id. At 1353. Many of
these pharmacological agents used also have a ventilatory
depressant action (such as benzodiazepines) or other side effects
such as urinary hesitancy and/or impotence in men (protriptyline)
so that a new agent with fewer side effects is needed for the
treatment of obstructive sleep apnea. Even though serotonin is a
sleep-inducing agent and may be a ventilatory stimulant (Id. At
1354), the COMPOUND of the present invention, which inhibits
serotonin at the 5HT2a receptor, has been found useful in treating
obstructive sleep apnea. See also Am. J. Respir Crit Care Med (153)
pp 776-786 (1996) where serotonin antagonists exacerbated sleep
apnea produced in English bulldogs. But compare, Journal of
Physiology (466) pp 367-382 (1993), where it is postulated that an
excess of serotonin due to dysfunction of the serotonin
biosynthesis mechanisms might set up conditions which favor
obstructive apneas; European Journal of Pharmacology (259):71-74
(1994) further work on rat model with 5HT2 antagonist.
[0009] Insomnia and obstructive sleep apnea are sometimes found in
conjunction with other conditions and sometimes those conditions
are treatable by the COMPOUND, e.g., patients suffering from
fibromyalgia may also have insomnia and/or sleep apnea. Am J Med
Sci 1998; 315(6):367-376. Having one pharmacological agent which
treats two or more existing or potential conditions, as does the
present invention, is probably more cost effective, leads to better
compliance and has fewer side effects than taking two or more
agents.
[0010] It is an object of the present invention to provide a
therapeutic agent for the use in treating sleep disorders. It is
another object of the present invention to provide one
pharmaceutical agent which may be useful in treating two or more
conditions wherein one of the conditions is insomnia or sleep apnea
and other conditions respond to treatment by the COMPOUND.
[0011] Subjective and Objective Determinations of Sleep
Disorders
[0012] There are a number of ways to determine whether the onset,
duration or quality of sleep (e.g. non-restorative or restorative
sleep) is impaired or improved. One method is a subjective
determination of the patient, e.g., do they feel drowsy or rested
upon waking. Other methods involve the observation of the patient
by another during sleep, e.g., how long it takes the patient to
fall asleep, how many times does the patient wake up during the
night, how restless is the patient during sleep, etc. Another
method is to objectively measure the stages of sleep.
[0013] Polysomnography is the monitoring of multiple
electrophysiological parameters during sleep and generally includes
measurement of EEG activity, electroculographic activity and
electromyographic activity, as well as other measurements. These
results, along with observations, can measure not only sleep
latency (the amount of time required to fall asleep), but also
sleep continuity (overall balance of sleep and wakefulness) which
may be an indication of the quality of sleep.
[0014] There are five distinct sleep stages which can be measured
by polysomnogrpahy: rapid eye movement (REM) sleep and four stages
of no-rapid eye movement (NREM) sleep (stages 1, 2, 3 and 4). Stage
1 NREM sleep is a transition from wakefulness to sleep and occupies
about 5% of time spent asleep in healthy adults. Stage 2 NREM
sleep, which is characterized by specific EEG waveforms (sleep
spindles and K complexes), occupies about 50% of time spent asleep.
Stages 3 and 4 NREM sleep (also known collectively as slow-wave
sleep) are the deepest levels of sleep and occupy about 10-20% of
sleep time. REM sleep, during which the majority of typical story
like dreams occur, occupies about 20-25% of total sleep.
[0015] These sleep stages have a characteristic temporal
organization across the night. NREM stages 3 and 4 tend to occur in
the first one-third to one-half of the night and increase in
duration in response to sleep deprivation. REM sleep occurs
cyclically through the night. Alternating with NREM sleep about
every 80-100 minutes. REM sleep periods increase in duration toward
the morning. Human sleep also varies characteristically across the
life span. After relative stability with large amounts of slow-wave
sleep in childhood and early adolescence, sleep continuity and
depth deteriorate across the adult age range. This deterioration is
reflected by increased wakefulness and stage 1 sleep and decreased
stages 3 and 4 sleep.
SUMMARY OF THE INVENTION
[0016] The present invention comprises a method of treating a
patient for a sleep disorder by administering to the patient a
therapeutically sufficient amount of
R-(+)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluoroph-
enyl)ethyl]-4-piperidinemethanol or a pharmaceutically acceptable
salt thereof. The sleep disorder can be insomnia (primary insomnia,
insomnia related to another mental disorder, or substance-induced
insomnia) or obstructive sleep apnea.
[0017] The present invention also comprises monotherapy for
treating a sleep disorder and another condition treatable by
administration of
R-(+)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperid-
inemethanol or a pharmaceutically acceptable salt thereof. Examples
of other conditions treatable by administration of
R-(+)-.alpha.-(2,3-dimeth-
oxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol or a
pharmaceutically acceptable salt thereof are schizophrenia,
fibromyalgia, obsessive compulsive disorder, coronary vasospasms,
thrombotic illness, angina, anorexia nervosa, Raynaud's phenomenon,
extrapyramidal symptoms, anxiety, arrythmias, depressive disorders,
and bipolar depression.
DETAILED DESCRIPTION OF THE INVENTION
[0018] As used herein, the following terms have these specified
meanings:
[0019] a) the term "patient refers to a warm-blooded animal, such
as for example, rats, mice, dogs, cats, guinea pigs, and primates
such as humans;
[0020] b) the term "treat" refers to either preventing, providing
symptomatic relief, or curing the patient's disease, disorder or
condition;
[0021] c) the term "administering" comprises administration via any
appropriate route such as oral, sublingual, buccal, transdermal,
inhalation, rectal or injection (including intramuscular,
intravenous, subcutaneous, etc.), or any other appropriate method
of providing the COMPOUND to the patient;
[0022] d) The term "therapeutically sufficient amount" means enough
of the COMPOUND which becomes bioavailable through the appropriate
route of administration to treat the patient for the disorder,
condition or disease;
[0023] e) The term "pharmaceutically acceptable salt" means either
an acid addition salt or a basic addition salt which is compatible
with the treatment of patients for the intended use.
"Pharmaceutically acceptable acid addition salt" is any non-toxic
organic or inorganic acid addition salt of the base compounds
represented by Formula I. Illustrative inorganic acids which form
suitable salts include hydrochloric, hydrobromic, sulfuric and
phosphoric acid and acid metal salts such as sodium monohydrogen
orthophosphate and potassium hydrogen sulfate. Illustrative organic
acids which form suitable salts include the mono-, di- and
tri-carboxylic acids. Illustrative of such acids are, for example,
acetic, glycolic, lactic, pyruvic, malonic, succinic, glutaric,
fumaric, malic, tartaric, citric, ascorbic, maleic, hydroxymaleic,
benzoic, hydroxybenzoic, phenylacetic, cinnamic, salicyclic,
2-phenoxybenzoic, p-toluenesulfonic acid and sulfonic acids such as
methanesulfonic acid and 2-hydroxyethanesulfonic acid. Either the
mono- or di-acid salts can be formed, and such salts can exist in
either a hydrated, solvated or substantially anhydrous form. In
general, the acid addition salts of these compounds are more
soluble in water and various hydrophilic organic solvents and which
in comparison to their free base forms, generally demonstrate
higher melting points. "Pharmaceutically acceptable basic addition
salts" means non-toxic organic or inorganic basic addition salts of
the compounds of Formula (I), if it can be made. Examples are
alkali metal or alkaline-earth metal hydroxides such as sodium,
potassium, calcium, magnesium or barium hydroxides; ammonia, and
aliphatic, alicyclic, or aromatic organic amines such as
methylamine, trimethylamine and picoline. The selection of the
appropriate salt may be important so that the ester is not
hydrolyzed. The selection criteria for the appropriate salt will be
known to one skilled in the art.
[0024] f) The term "Restorative Sleep" means sleep which produces a
rested state upon waking;
[0025] g) the term "Sleep Disorder" means insomnia and obstructive
sleep apnea;
[0026] h) the term "Insomnia" means primary insomnia, insomnia
related to another mental disorder, and substance-induced
insomnia;
[0027] i) The term "Primary Insomnia" means difficulty in
initiating sleep, in maintaining sleep or having restorative sleep
which is not caused by a mental disorder or due to physiological
effects of taking or withdrawing from certain substances
(substance-induced). As used herein, it also includes circadian
rhythm insomnia which is insomnia due to a change in the normal
sleep-wake schedule (shift changes, jet lag, etc.);
[0028] j) The term "Insomnia related to another Mental Disorder"
means difficulty in initiating sleep, in maintaining sleep or
having restorative sleep which is caused by an underlying mental
disorder such as, for example, depression, anxiety or
schizophrenia;
[0029] k) The term "Substance-Induced Insomnia" means difficulty in
initiating sleep, in maintaining sleep or having restorative sleep
which is caused by physiological effects of taking or withdrawing
from certain substances such as caffeine, alcohol, amphetamine,
opioids, sedatives, hypnotics and anxiolytics; and
[0030] l) The term "Obstructive Sleep Apnea" means repeated
episodes of upper-airway obstruction during sleep and is normally
characterized by loud snores or brief gasps that alternate with
episodes of silence.
[0031] The COMPOUND may be synthesized by methods known in the art,
such as one previously described in U.S. Pat. No. 5,134,149,
incorporated herein by reference. 12
[0032] In Step A of Reaction Scheme I, an esterification reaction
is carried out between racemic
.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorop-
henyl)ethyl]-4-piperidinemethanol (structure 1) and the (+)-isomer
of .alpha.-methoxyphenylacetic acid (structure 2). This
esterification produces the diastereomeric mixture identified as
structure 3. These diastereomers are subjected to silica gel
chromatography which separates the two diastereomers, thereby
isolating the (+,+) diastereomer as is depicted in Step B. In Step
C, the (+,+) diastereomer is hydrolyzed which produces the
(+)-isomer of .alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluoroph-
enyl)ethyl]-4-piperidinemethanol.
[0033] The esterification reaction can be carried out using
techniques known in the art. Typically approximately equivalent
amounts of racemic
.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemet-
hanol and the (+)-isomer of .alpha.-methoxyphenylacetic acid are
contacted in an organic solvent such as methylene chloride, THF,
chloroform, toluene and heated to reflux for a period of time
ranging from 5 to 24 hours. The esterification is typically carried
out in the presence of an equivalent amount of
dicyclohexylcarbodiimide and a catalytic amount of
4-dimethylaminopyridine. The resulting diastereomers can be
isolated by filtration of the dicyclohexylurea and evaporation of
the filtrate.
[0034] The diastereomers are then subjected to silica gel
chromatography which separates the (+,+) and the (-,+)
diastereomers. This chromatographic separation may be carried out
as is known in the art. A 1:1 mixture of hexane and ethyl acetate
is one suitable eluent.
[0035] The resulting (+,+) diastereomer is then subjected to a
hydrolysis reaction which produces the (+)-isomer of
.alpha.-(2,3-dimethoxyphenyl)-1-
-[2-(4-fluorophenyl)ethyl]-4-piperidine-methanol. The hydrolysis is
carried out by contacting the diastereomer with an excess of a base
such as potassium carbonate in an aqueous alcoholic solution. The
hydrolysis is carried out at a temperature of about 15 to
30.degree. C. for a period of time ranging from 2 to 24 hours. The
resulting (+)-isomer of
.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemet-
hanol may then be recovered by dilution with water and extraction
with methylene chloride. It is then purified by recrystallization
from a solvent system such as cyclohexane/hexane or ethyl
acetate/hexane.
[0036] Methods for producing the starting materials of Reaction
Scheme I are known in the art. For example, U.S. Pat. No. 4,783,471
teaches how to prepare racemic
.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-
-4-piperidine-methanol. This patent is hereby incorporated by
reference. Examples No. 1 and 2 of this application also teach
suitable methods. Alternatively, racemic
.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl-
)ethyl]-4-piperidinemethanol can be prepared in the following
manner. Initially 4-hydroxypiperidine is subjected to an
N-alkylation reaction with p-fluorophenylethyl bromide which
produces 4-hydroxy-1-[2-(4-fluorop- henyl)ethyl]-piperidine. This
compound is brominated with Ph.sub.3P.Br.sub.2 which produces
4-bromo-1-[2-(4-fluorophenyl)ethyl]pipe- ridine. This compound is
contacted with Mg thereby forming a Grignard Reagent which is then
reacted with 2,3-dimethoxybenzaldehyde which produces the desired
product (.+-.)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-
-fluorophenyl)ethyl]-4-piperidinemethanol. The (+)-isomer of
.alpha.-methoxyphenylacetic acid is known in the art.
[0037] Examples 1, 2 and 3 show one method of making the COMPOUND.
Examples 4 and 5 provide data on the method of using the
COMPOUND.
EXAMPLE 1
[0038] Example 1, Steps A-D, demonstrates the preparation of the
starting material
(.+-.)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-
-4-piperidinemethanol, structure 1.
A) 1-[2-(4-Fluorophenyl)ethyl]-4-piperidinecarboxamide
[0039] A solution of isonipectoamide (10.9 g, 85.0 mmol),
2-(4-fluorophenyl)ethyl Bromide (15.7 g, 77.3 mmol), and
K.sub.2CO.sub.3 (2.3 g, 167 mmol) was prepared in DMF (280 mL) and
stirred under argon at 90-95.degree. C. overnight. The cooled
solution was concentrated to a white oily solid. The solid was
partitioned between water and CH.sub.2Cl.sub.2. The layers were
separated and the aqueous layer was extracted with
CH.sub.2Cl.sub.2. The combined organic layers were washed 2.times.
with water, dried (MgSO.sub.4), filtered, and evaporated to an oily
solid. The solid was recrystallized from EtOAc to afford
1-[2-(4-fluorophenyl)ethyl]-4-piperidinecarboxamide as a white
powder, m.p. 177-178.degree. C. (decomp.). Anal. Calcd. for
C.sub.14H.sub.19FN.sub.2O: C, 67.18; H, 7.65: N, 11.19. Found: C,
67.25; H, 7.67; N, 11.13.
B) 4-Cyano-1-[2-(4-fluorophenyl)ethyl]piperidine
[0040] To stirred phosphorus oxychloride (25 ml, 41.12 g, 268 mmol)
and sodium chloride (5.1 g, 87.3 mmol) was added
1-[2-(4-fluorophenyl)ethyl]-- 4-piperidinecarboxamide (8.9 g, 35.6
mmol) portionwise. After complete addition, the solution was
refluxed for 2 hours. The cooled solution was poured into dilute
NH.sub.4OH to destroy the POCl.sub.3. The aqueous solution was
cooled to 0.degree. C., then extracted 2.times. with
CH.sub.2Cl.sub.2. The combined organic layers were dried
(MgSO.sub.4), filtered, and evaporated to afford 8.1 g of an oily
solid. The solid was distilled, (b.p. 150.degree. C., 0.1 mm Hg),
to afford a clear, colorless oil that solidified. This material was
crystallized from hexane to afford
4-cyano-1-[2-(4-fluorophenyl)ethyl]piperidine as white needles,
m.p. 47-48.degree. C. Anal. Calcd. for C.sub.14H.sub.17FN.sub.2: C,
72.39; H, 7.38; N, 12.06. Found: C, 72.62; H, 7.49; N, 12.12.
C) 1-[2-(4-Fluorophenyl)ethyl]-4-piperidinecarboxaldehyde
[0041] To a stirred solution of
4-cyano-1-[2-(4-fluorophenyl)-ethyl]piperi- dine (1.00 g, 4.3 mmol)
in THF (20 mL) under argon at 0.degree. C. was added DIBAL-H (4.6
mL of a 1.0 M solution in THF, 4.6 mmol) via syringe. After
stirring overnight at room temperature, 10% aqueous HCl (25 mL) was
added and the solution was stirred for 3 hours. The entire mixture
was then poured into 10% aqueous NaOH (50 mL), then extracted
2.times. with ether. The combined organic layers were washed with
brine, dried (MgSO.sub.4), filtered, and evaporated to afford a
pale yellow oil. The oil was chromatographed on silica gel, eluting
with EtOAc. The appropriate fractions were combined and evaporated
to afford an oil. This oil was distilled (b.p. 166.degree. C., 0.05
mm Hg) to afford
1-[2-(4-fluorophenyl)ethyl]-4-piperidinecarboxaldehyde, obtained as
a colorless oil. Anal. Calcd. for C.sub.14H.sub.18FNO: C, 71.46; H,
7.71; N, 5.95. Found: C, 71.08; H, 7.81; N, 5.86.
D)
(.+-.)-.alpha.-(2,3-Dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-pipe-
ridinemethanol
[0042] To a stirred solution of veratrole (0.93 g, 6.7 mmol) in THF
(20 mL) under argon at 0.degree. C. was added n-BuLi (2.7 mL of a
2.5 M solution in hexane, 6.75 mmol). After stirring 2.5 h, the
solution was cooled to -78.degree. C. and treated with
1-[2-(4-fluorophenyl)ethyl]-4-p- iperidinecarboxaldehyde (1.30 g,
5.5 mmol) in THF (25 mL) via an additional funnel. The cooling bath
was removed and the solution was allowed to stir for 2 hours. Water
was added, the layers separated, and the aqueous layer was
extracted with EtOAc. The combined organic layers were washed with
brine, dried (MgSO.sub.4), filtered, and chromatographed on silica
gel, eluting with acetone. The appropriate fractions were combined
and evaporated to afford a white solid. The solid was
recrystallized from hexane to afford racemic
.alpha.-(2,3-dimethoxyphenyl-
)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol as shiny white
needles, m.p. 126-127.degree. C. Anal. Calcd. for
C.sub.22H.sub.28FNO.sub.3: C, 70.75; H, 7.56; N, 3.75. Found: C,
70.87; H, 7.65; N, 3.68.
EXAMPLE 2
[0043] Example 2, Steps A-F, demonstrate an alternative manner of
preparing
(.+-.)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl-
]-4-piperidinemethanol, structure 1.
A) 1-(1,1-Dimethylethyl)-1,4-piperidinedicarboxylic acid
[0044] To isonipecotic acid (107.5 g, 832 mmol) stirred in 1N NaOH
(40 g NaOH in 900 mL H.sub.2O) and tert-butanol (1800 mL) was added
di-tert-butyl dicarbonate (200 g, 916 mmol) in portions. After
stirring overnight, the solution was concentrated and the resulting
water layer was extracted 3.times. with ether. The combined organic
layers were washed with water, brine, dried (MgSO.sub.4), filtered,
and evaporated to a white solid, which was recrystallized from
EtOAc/hexane (300 mL/200 mL) to afford
1-(1,1-dimethylethyl)-1,4-piperidinedicarboxylic acid as white
needles, m.p. 147-149.degree. C.
B) 4-(N-methoxy-N-methylcarboxamido)-1-piperidinecarboxylic acid
1,1-dimethylethyl ester
[0045] To a stirred solution of
1-(1,1-dimethylethy)-1,4-piperidinedicarbo- xylic acid (50.0 g, 218
mmol) in anhydrous CH.sub.2Cl.sub.2 (500 mL) under N.sub.2 in a 2L
flask was added 1,1'-carbonyldiimidazole (38.9 g, 240 mmol)
portionwise. After stirring for 1 hour, N,O-dimethylhydroxylamine
hydrochloride (23.4 g, 240 mmol) was added in one portion. After
stirring overnight, the solution was washed twice with 1N HCl,
twice with saturated NaHCO.sub.3, once with brine, dried
(MgSO.sub.4), filtered, and evaporated to an oil. Distillation
afforded 4-(N-methoxy-N-methylcarboxam- ido)-1-piperidinecarboxylic
acid 1,1-dimethylethyl ester as a clear oil, b.p. 120-140.degree.
C., 0.8 mm.
C) 4-(2,3-Dimethoxybenzoyl)-1-piperidinecarboxylic acid
1,1-dimethylethyl ester
[0046] n-Butyl lithium (14.5 mL of a 2.5 M solution in hexane, 36.3
mmol) was added via syringe to a stirred solution of veratrole
(5.00 g, 36.2 mmol) in THF (50 mL, anhydrous) under argon at
0.degree. C. The ice bath was removed and the mixture was allowed
to stir for 90 minutes. The mixture was cooled to -78.degree. C.
and treated with
4-(N-methoxy-N-methylcarboxamido)-1-piperidinecarboxylic acid
1,1-dimethylethyl ester (9.20 g, 33.8 mmol) in THF (50 mL,
anhydrous) via syringe. The cooling dry ice-acetone bath was
removed and the mixture was allowed to come to room temperature.
After stirring for 3 hours, saturated aqueous NH.sub.4Cl was added
and the mixture was allowed to stir overnight. The layers were
separated and the aqueous layer was extracted with ether. The
combined organic layers were washed with brine, dried (MgSO.sub.4),
filtered, and evaporated to afford an amber oil. The oil was
chromatographed on silica gel, eluting with 20% EtOAc in hexane.
The appropriate fractions were combined and evaporated to an amber
oil. The oil was distilled to afford
4-(2,3-dimethoxybenzoyl)-1-piperidinecarb- oxylic acid
1,1-dimethylethyl ester as a colorless oil. (b.p. 225-250.degree.
C., 0.05 mm). Anal. Calcd. for C.sub.19H.sub.27NO.sub.5: C, 65.31;
H, 7.79; N, 4.01. Found: C, 65.04; H, 7.92; N, 4.11.
D) 4-(2,3-Dimethoxyphenyl)-4-piperidinylmethanone
[0047] 4-(2,3-Dimethoxybenzoyl)-1-piperidinecarboxylic acid
1,1-dimethylethyl ester (7.75 g, 22.2 mmol) was dissolved in
trifluoroacetic acid (50 mL, 650 mmol) and stirred for 45 minutes.
The entire solution was poured into ether (900 mL) and allowed to
stand overnight. Filtration yielded
4-(2,3-dimethoxyphenyl)-4-piperidinylmethan- one trifluoroacetate
as fine white needles, m.p. 123.degree. C. Anal. Calcd. for
C.sub.14H.sub.19NO.sub.3.CF.sub.3CO.sub.2H: C, 52.89; H, 5.55; N,
3.86. Found: C, 52.77; H, 5.62; N, 3.82.
[0048] The resulting 4-(2,3-dimethoxyphenyl)-4-piperidinylmethanone
trifluoroacetate was dissolved in water, treated with NaOH (10%
aqueous) until basic, and extracted three times with
dichloromethane. The combined organic layers were washed with
brine, dried (MgSO.sub.4), filtered and evaporated to afford
4-(2,3-dimethoxyphenyl)-4-piperidinylmethanone as an oil.
E)
(2,3-Dimethoxyphenyl)[1-[2-(4-fluorophenyl)ethyl]-4-piperidinyl]methano-
ne monohydrochloride
[0049] A solution of 4-(2,3-dimethoxyphenyl)-4-piperidinylmethanone
(8.00 g, 32.1 mmol) and 2-(4-fluorophenyl)ethyl bromide (6.52 g,
32.1 mmol) was prepared in DMF (90 mL) treated with K.sub.2CO.sub.3
(7.0 g, 50.7 mmol), then stirred and heated at 80.degree. C. under
argon overnight. The cooled solution was poured into a partition of
2/1 EtOAc/toluene and water. The layers were separated and the
aqueous layer was extracted with 2/1 EtOAc/toluene. The combined
organic layers were washed 2.times. with water, 1.times. with
brine, dried (MgSO.sub.4), filtered, and evaporated to afford 11.0
g of an oil. The oil was chromatographed on silica gel, eluting
with EtOAc. The appropriate fractions were combined, concentrated,
dissolved in ethyl acetate and treated with HCl/ethyl acetate.
(2,3-dimethoxyphenyl)[1-[2-(4-fluorophenyl)ethyl]-4-piperidinyl]-
-methanone monohydrochloride was obtained as a precipitate, m.p.
225-227.degree. C. (decomp). Anal. Calcd. for
C.sub.22H.sub.26FNO.sub.3.H- Cl: C, 64.78; H, 6.67; N, 3.43. Found:
C, 64.44; H, 6.73; N, 3.41.
F)
(.+-.)-.alpha.-(2,3-Dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-pipe-
ridinemethanol
[0050] To a stirred solution of
(2,3-dimethoxyphenyl)[1-[2-(4-fluorophenyl-
)ethyl]-4-piperidinyl]-methanone (6.0 g, 16.2 mmol) in MeOH (100
mL) at 0.degree. C. was added NaBH.sub.4 (1240 mg, 32.8 mmol) in
two portions, over an one hour period. After stirring overnight,
the solution was concentrated to a solid. The solid was partitioned
between water and ether. The layers were separated and the aqueous
layer was extracted with ether. The combined organic layers were
washed with brine, dried (MgSO.sub.4), filtered, and evaporated to
a solid. The solid was chromatographed on silica gel, eluting with
acetone. The appropriate fractions were combined and evaporated to
afford a white solid. The solid was recrystallized from cyclohexane
to afford (.+-.)-.alpha.-(2,3-dimetho-
xyphenyl)-1-[2-(4-fluorophenyl)-ethyl]-4-piperidinemethanol as
white needles, m.p. 126-127.degree. C. Anal. Calcd. for
C.sub.22H.sub.28FNO.sub- .3: C, 70.75; H, 7.56; N, 3.75. Found: C,
70.86; H, 7.72; N, 3.93.
EXAMPLE 3
[0051] This example demonstrates the preparation of the compound of
Formula-I.
Preparation of
(+)-.alpha.-(2,3-Dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethy-
l]-4-piperidinemethanol
A) Preparation of Diastereomers
[0052] A solution of 3.90 g (10.4 mmol) of
(.+-.)-.alpha.-(2,3-dimethoxyph-
enyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol, 1.74 g
(10.4 mmol) of S-(+)-.alpha.-methoxyphenylacetic acid, 2.15 g (10.4
mmol) of 1,3-dicyclohexylcarbodiimide and 0.1 g of
4-dimethylaminopyridine in chloroform (75 mL) was refluxed for 17
hours, allowing to cool to room temperature and filtered. The
filtrate was concentrated and chromatographed on a silica gel
column eluting with ethyl acetate/hexane (1:1) to afford two
diastereomers, Rf=0.1 and 0.2 (TLC EtOAc/hexane, 1:1). Intermediate
fractions were re-chromatographed to give additional material.
Those fractions with Rf=0.2 were combined to give a single
diastereomeric ester,
(+,+)-(2,3-dimethoxyphenyl)[1-[2-(4-fluorophenyl)et-
hyl]-4-piperidinyl]methyl-.alpha.-methoxybenzene-acetate.
B) Preparation of
(+)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)e-
thyl]-4-piperidinemethanol
[0053] To a stirred solution of 0.97 g (1.9 mmol) of the above
mentioned diastereomeric ester, Rf=0.2, in 25 mL of methanol was
added 0.5 g (3.6 mmol) of potassium carbonate and 5.0 mL of water.
After stirring 17 hours at room temperature the reaction mixture
was diluted with water and extracted twice with methylene chloride.
The combined extracts were washed with water, brine and dried over
MgSO.sub.4. After filtering, the filtrate was concentrated to an
oil and crystallized from 40 mL of cyclohexane/hexane (1:1) to give
(+)-.alpha.-(2,3-dimethoxyphenyl)-1-[2-(-
4-fluorophenyl)ethyl]-4-piperidinemethanol, m.p. 112-113.degree.
C., [.alpha.].sub.D.sup.20=+13.9.degree..
[0054] The COMPOUND can be formulated into pharmaceutical dosage
forms using techniques well known in the art. For oral
administration, the compound can be formulated into solid or liquid
preparations such as capsules, pills, tablets, lozenges, melts,
powders, suspensions, or emulsions. Solid unit dosage forms can be
capsules of the ordinary gelatin type containing, for example,
surfactants, lubricants and inert fillers such as lactose, sucrose,
and cornstarch or they can be sustained release preparations. In
another embodiment, the compound can be tableted with conventional
tablet bases such as lactose, sucrose, and cornstarch in
combination with binders, such as acacia, cornstarch, or gelatin,
disintegrating agents, such as potato starch or algenic acid, and a
lubricant such as stearic acid or magnesium stearate. Liquid
preparations are prepared by dissolving the active ingredient in an
aqueous or non-aqueous pharmaceutically acceptable solvent which
may also contain suspending agents, sweetening agents, flavoring
agents, and preservative agents as are known in the art.
[0055] For parenteral administration, the compound or its salts may
be dissolved in a physiologically acceptable pharmaceutical carrier
and administered as either a solution or a suspension. Illustrative
of suitable pharmaceutical carriers are water, saline, dextrose
solutions, fructose solutions, ethanol, or oils of animal,
vegetable, or synthetic origin. The pharmaceutical carrier may also
contain preservatives, buffers, etc. as are known in the art.
[0056] The dosage range at which the COMPOUND exhibits its ability
to treat sleep disorders, including each specific type of sleep
disorder, can vary depending upon the specific disorder, its
severity, the patient, any underlying disease states that the
patient is suffering from, and other medications that may be
concurrently administered to the patient. Generally though, this
COMPOUND will exhibit its ability to treat sleep disorders at a
range of 0.001 mg/kg/day to about 100 mg/kg/day. It may be
delivered by any appropriate means, such as orally, sublingually,
buccally, transdermally, rectal via suppository, inhalation or
injection.
EXAMPLE 4
[0057] A) In five healthy subjects received a single 10 mg dose of
the COMPOUND and seven subjects received a single 20 mg dose of the
COMPOUND administered orally. Forty percent of the subjects
receiving the 20 mg dose (2 out of 5) and sixty percent of the
subjects receiving the 10 mg dose (3 out of 5) experienced mild to
moderate sedation.
[0058] B) Forty-nine patients diagnosed with schizophrenia received
either 10 mg of the COMPOUND (5 mg twice daily), 20 mg of the
COMPOUND (10 mg twice daily), 40 mg of the COMPOUND (20 mg twice
daily) or placebo orally twice daily. The following was
reported:
1 Placebo 10 mg 20 mg 40 mg Total Insomnia N = 1; N = 0; N = 3: N =
3; N = 7; 14.3% 0% 21.4% 23.1% 14.3% Somnolence N = 0; N = 3; N =
1; N = 2; N = 6; 0% 20% 15.4% 15.4% 12.2%
[0059] The milligram (mg) amounts refer to the amount of the
COMPOUND orally administered to the subjects and "n" refers to the
number of subjects that reported the effect. This chart shows that
although some insomnia was reported by some subjects having
schizophrenia, some subjects also reported somnolence.
[0060] C) Doses of 36 mg, 72 mg, 108 mg and 138 mg of the COMPOUND
and placebo were orally administered to healthy subjects. The
following data were reported.
2 Placebo 9 mg 18 mg 36 mg 72 mg 108 mg 138 mg n = 6 n = 4 n = 4 n
= 4 n = 4 n = 4 n = 4 Drowsiness 33% 50% 100% 100% 75% 100% 100% n
= 3 n = 2 n = 4 n = 4 n = 3 n = 4 n = 4
[0061] The drowsiness was rated as mild or moderate at doses below
72 mg and moderate to severe at 72 mg and above.
[0062] D) In healthy subjects, the COMPOUND was administered in 3
mg (n=4), 9 mg (n=4), 18 mg (n=4), 36 mg (n=4) and 72 mg (n=4)
doses along with the placebo (n=5) wherein "n" is the number of
subjects. Only the group receiving the 72 mg dose reported
drowsiness (n=3).
EXAMPLE 5
[0063] Intraperitoneal application of L-Tryptophan (10 mg/kg) and
Pargyline (50 mg/kg) to anaesthetized newborn rats depressed the
amplitude of the inspiratory discharges of the genioglossal muscle
and induced obstructive apneas (OA). The following shows that the
COMPOUND is efficient in preventing these effects and compares its
efficiency to theophylline.
[0064] Experiments were carried out on newborn Sprague Dawley rats
from Iffa Credo breeding center. The animals were anaesthetized by
intraperitoneal injection of low doses of sodium pentobarbitone
(7-10 mg/kg), kept lying (dorsal cubitus) on a warming blanket and
were spontaneously ventilating.
[0065] The EMG activity of the genioglossal muscles and the
diaphragm were recorded with fine insulated wires (bipolar
recordings) inserted within the muscles, filtered (100-3,000 Hz),
amplified (.times.5-10,000) and integrated (time constant 50 ms).
The rib cage movements were recorded via a captor gently touching
the lower ribs and/or the abdominal wall. The airflow changes
resulting from the respiratory chest movements were recorded via a
facial mask and a highly sensitive pressure recorder.
Effects of Compound on Depression of Genioglossal EMG Induced by
L-Tryptophan and Pargyline
[0066] Ten to fifteen minutes after induction of anesthesia, the
animals received first an intraperitoneal injection of the
COMPOUND, and a control recording was taken to define the mean
amplitude of the integrated EMGs. Then, the animal received an
intraperitoneal injection of L-Tryptophan plus Pargyline
("L-Trp+Parg") 10 mg/kg and 50 mg/kg, respectively, and the changes
in EMG amplitudes were checked every 10 minutes and were expressed
as % of control values.
[0067] In ten animals, the pre-treatment with MDL 100,907 at 0.1
mg/kg did not prevent the depression of genioglossal (GG) discharge
induced by injection of L-Trp+Parg. L-Trp+Parg injection
significantly depressed by 30-50% the mean GG discharge for about
30 minutes. A larger dose of the COMPOUND (1 mg/kg) was applied in
ten other newborn rats and this pre-treatment was now efficient in
preventing the GG depression. Finally, ten more animals received
the largest dose used of the COMPOUND (3 mg/kg) and confirmed the
efficiency of the COMPOUND.
Effects of the Compound Pretreatment on the Occurrence of
Obstructive Apnea Induced by L-Tryptophan and Pargyline
Injection
[0068] The respiratory movements and resulting air flow changes
were measured in 30 newborn rats which received first a
pre-treatment with the COMPOUND at either 0.1, 1 or 3 mg/kg and 10
min later L-Trp+Parg injection. L-Trp+Parg injection induced OAs in
9 of 10 newborn rats which received the COMPOUND at 0.1 mg/kg, and
4 of the 10 animals eventually died of respiratory distress,
similar to animals from previous studies which received L-Trp+Prg
alone.
[0069] Five out of ten newborn rats which received the COMPOUND at
1 mg/kg did not present short lasting OAs at all after L-Trp+Parg
injection. Among the 5 of 10 newborn rats which displayed OAs, 2
animals had infrequent OAs (less than 5 short lasting OAs in 60
minutes). The mean curve calculated for the 1 mg/kg sample revealed
a peak frequency of occurrence of short lasting OAs between 20-40
min after the injection (range 4 OAs per 10 minute period) which
was significantly less than that observed in the 0.1 mg/kg sample.
After 1 mg/kg pre-treatment with the COMPOUND, long lasting OAs
were observed in only one newborn rat and all animals survived to
L-Trp+Parg injection. Applying the largest dose of the COMPOUND (3
mg/kg) confirmed the COMPOUND efficiency in preventing OAs. Only 2
of 10 treated rats presented frequent short lasting OAs, 3 of 10
had a total of less than 3 short lasting OAs, and 5 of 10 showed no
short lasting OAs. None of the 10 animals displayed long lasting
OAs and all survived.
Effects of Theophylline Pre-Treatment on the Occurrence of
Obstructive Apneas Induced by L-Tryptophan and Pargyline
Injection
[0070] Five newborn rats received theophylline at 10 mg/kg and 5
other animals received theophylline at 30 mg/kg. In both cases,
L-Trp+Prg injection depressed the amplitude of GG inspiratory
discharges and this effect was not prevented by either dose of
theophylline. In a second set of experiments, induction of OAs
after L-Trp+Prg injection also was not prevented by theophylline at
10 or 30 mg/kg.
* * * * *