Methods of treating or preventing sleep apnea

This invention provides methods for the treatment or prevention of sleep apnea in a mammal which comprise administering to a mammal in need thereof an effective amount of a compound of formula (I) where R.sup.1 and R.sup.2 are independently selected from the group consisting of hydrogen, methyl, methoxy, chloro, and trifluoromethyl, with the proviso that no more than one of R.sup.1 and R.sup.2 can be hydrogen; and Y is (a), (b), (c), (d), (e), (f), N-R.sup.a, or CH-NR.sup.b R.sub.c, where R.sup.a, R.sup.b, and R.sup.c are independently selected from the group consisting of hydrogen and C.sub.1 -C.sub.6 alkyl; or a pharmaceutically acceptable salt or solvate thereof.

BACKGROUND OF THE INVENTION 
Tachykinins are a family of peptides which share a common amidated carboxy 
terminal sequence. Substance P was the first peptide of this family to be 
isolated, although its purification and the determination of its primary 
sequence did not occur until the early 1970's. 
Between 1983 and 1984 several groups reported the isolation of two novel 
mammalian tachykinins, now termed neurokinin A (also known as substance K, 
neuromedin L, and neurokinin a), and neurokinin B (also known as 
neuromedin K and neurokinin .beta.). See, J. E. Maggio, Peptides, 6 
(Supplement 3):237-243 (1985) for a review of these discoveries. 
Tachykinins are widely distributed in both the central and peripheral 
nervous systems, are released from nerves, and exert a variety of 
biological actions, which, in most cases, depend upon activation of 
specific receptors expressed on the membrane of target cells. Tachykinins 
are also produced by a number of non-neural tissues. 
The mammalian tachykinins substance P, neurokinin A, and neurokinin B act 
through three major receptor subtypes, denoted as NK-1, NK-2, and NK-3, 
respectively. These receptors are present in a variety of organs. 
Substance P is believed inter alia to be involved in the neurotransmission 
of pain sensations, including the pain associated with migraine headaches 
and with arthritis. These peptides have also been implicated in 
gastrointestinal disorders and diseases of the gastrointestinal tract such 
as inflammatory bowel disease. Tachykinins have also been implicated as 
playing a role in numerous other maladies, as discussed infra. 
Tachykinins play a major role in mediating the sensation and transmission 
of pain or nociception, especially migraine headaches. see. e.g., S. L. 
Shepheard, et al., British Journal of Pharmacology 108:11-20 (1993); S. M. 
Moussaoui, et al., European Journal of Pharmacology, 238:421-424 (1993); 
and W. S. Lee, et al., British Journal of Pharmacology, 112:920-924 
(1994). 
In view of the wide number of clinical maladies associated with an excess 
of tachykinins, the development of tachykinin receptor antagonists will 
serve to control these clinical conditions. The earliest tachykinin 
receptor antagonists were peptide derivatives. These antagonists proved to 
be of limited pharmaceutical utility because of their metabolic 
instability. 
Recent publications have described novel classes of non-peptidyl tachykinin 
receptor antagonists which generally have greater oral bioavailability and 
metabolic stability than the earlier classes of tachykinin receptor 
antagonists. Examples of such newer non-peptidyl tachykinin receptor 
antagonists are found in U.S. Pat. No. 5,328,927, issued Jul. 12, 1994; 
U.S. Pat. No. 5,360,820, issued Nov. 1, 1994; U.S. Pat. No. 5,344,830, 
issued Sep. 6, 1994; U.S. Pat. No. 5,331,089, issued Jul. 19, 1994; 
European Patent Publication 591,040 A1, published Apr. 6, 1994; Patent 
Cooperation Treaty publication WO 94/01402, published Jan. 20, 1994; 
Patent Cooperation Treaty publication WO 94/04494, published Mar. 3, 1994; 
and Patent Cooperation Treaty publication WO 93/011609, published Jan. 21, 
1993. 
Sleep apnea is a condition in which apnea coours during sleep without 
subjective symptom. It is more prevailing in male middle and old-aged 
persons in their forties and fifties. Approximately one per 100 persons is 
reported to suffer from this condition. In sleep apena there is repeated 
many times in sleep a sequence of 20-40 seconds apnea, about 10-20 seconds 
pneusis, and 20-40 seconds apnea. For example, during a 6.5 hour sleep, 
approximately 400 occurrences of apnea may occur. 
As a result of sleep apnea there occur phenomena, such as daytime 
sleepiness, loss of energy or appetite, swelling in the lower part of the 
body, and shortness of breath. Increase in leukocyte number, development 
of polycythemia, and even cardiomegaly are associated with severe 
instances of sleep apnea. Sleep apnea is observed not only in adults of 
middle or advanced age, but also in infants, and may be an indirect cause 
of hypertension, cardiac insufficiency, and arrhythmia, possibly being a 
leading cause of sudden infant death syndrome. 
Several thousand apparently healthy infants (children under the age of one 
year) die each year in the United States from Sudden Infant Death Syndrome 
(SIDS). Deaths from SIDS have been estimated at 7,000 to 10,000 per year. 
The occurrence of SIDS in a given family can be particularly devastating 
emotionally because, in general, there is no warning that the infant is at 
risk and the parent or care giver has no knowledge of any problem until he 
or she discovers an unconscious or deceased infant thought to be safely 
sleeping in its crib. 
Therapies currently adopted for sleep apnea include bodyweight reduction, 
pressure application through the nose, surgical operation, and the use of 
a drug, such as acetazolamide. U.S. Pat. No. 5,422,374, issued Jun. 6, 
1995, describes the use of ubidecarenone to treat sleep apnea. U.S. Pat. 
No. 5,356,934, issued Oct. 18, 1994, describes the use of serotonin 
agonists, most preferably (R)-fluoxetine, to treat sleep apnea. Both of 
these patents are herein incorporated by reference. 
Because of the current dissatisfaction of the currently marketed treatments 
for sleep apnea within the affected population, there exists a need for a 
more efficacious and safe treatment. 
SUMMARY OF THE INVENTION 
This invention provides methods for the treatment or prevention of sleep 
apnea in a mammal which comprise administering to a mammal in need thereof 
an effective amount of a compound of Formula I 
##STR1## 
where R.sup.1 and R.sup.2 are independently selected from the group 
consisting of hydrogen, methyl, methoxy, chloro, and trifluoromethyl, with 
the proviso that no more than one of R.sup.1 and R.sup.2 Can be hydrogen; 
and 
##STR2## 
where R.sup.a, R.sup.b, and R.sup.c are independently selected from the 
group consisting of hydrogen and C.sub.1-6 alkyl; 
or a pharmaceutically acceptable salt or solvate thereof.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS 
The terms and abbreviations used in the instant examples have their normal 
meanings unless otherwise designated. For example ".degree.C." refers to 
degrees Celsius; "N" refers to normal or normality, "mol" refers to mole 
or moles; "mmol" refers to millimole or millinoles; "g" refers to gram or 
grams; "kg" refers to kilogram or kilograms; "L" refers to liter or 
liters; "ml" means milliliter or milliliters; "M" refers to molar or 
molarity; "MS" refers to mass spectrometry; and "NMR" refers to nuclear 
magnetic resonance spectroscopy. 
As used herein, the term "C.sub.1-6 alkyl" refers to straight or branched, 
monovalent, saturated aliphatic chains of 1 to 6 carbon atoms and 
includes, but is not limited to, methyl, ethyl, propyl, isopropyl, butyl, 
isobutyl, t-butyl, pentyl, isopentyl, and hexyl. The term "C.sub.1-6 
alkyl" includes within its definition the term "C.sub.1-3 alkyl". 
"Halo" represents chloro, fluoro, bromo or iodo. 
The term "haloformate" as used herein refers to an ester of a haloformic 
acid, this compound having the formula 
##STR3## 
wherein X is halo, and R.sup.d is C.sub.1-6 alkyl. Preferred haloformates 
are bromoformates and chloroformates. Especially preferred are 
chloroformates. Those haloformates wherein R.sup.d is C.sub.3-6 alkyl are 
especially preferred. Most preferred is isobutylchloroformate. 
The compounds prepared in the processes of the present invention have an 
asymmetric center. As a consequence of this chiral center, the compounds 
produced in the present invention may occur as racemates, mixtures of 
enantiomers and as individual enantiomers, as well as diastereomers and 
mixtures of diastereomers. Processes for preparing such asymmetric forms, 
individual isomers and combinations thereof, are within the scope of the 
present invention. 
The terms "R" and "S" are used herein as commonly used in organic chemistry 
to denote specific configuration of a chiral center. The term "R" (rectus) 
refers to that configuration of a chiral center with a clockwise 
relationship of group priorities (highest to second lowest) when viewed 
along the bond toward the lowest priority group. The term "S" (sinister) 
refers to that configuration of a chiral center with a counterclockwise 
relationship of group priorities (highest to second lowest) when viewed 
along the bond toward the lowest priority group. The priority of groups is 
based upon their atomic number (in order of decreasing atomic number). A 
partial list of priorities and a discussion of stereochemistry is 
contained in NOMENCLATURE OF ORGANIC COMPOUNDS: PRINCIPLES AND PRACTICE, 
(J. H. Fletcher, et al., eds., 1974) at pages 103-120. 
In addition to the (R)-(S) system, the older D-L system is also used in 
this document to denote absolute configuration, especially with reference 
to amino acids. In this system a Fischer projection formula is oriented so 
that the number 1 carbon of the main chain is at the top. The prefix "D" 
is used to represent the absolute configuration of the isomer in which the 
functional (determining) group is on the right side of the carbon atom at 
the chiral center and "L", that of the isomer in which it is on the left. 
Patent Cooperation Treaty Publication WO 95/14017, published May 26, 1995, 
teaches, inter alia, a series of tachylinin receptor antagonists of 
Formula II 
##STR4## 
wherein: m and n are independently 0-6; 
Z is --(CHR.sup.4)p-(CHR.sup.6)q-, where, 
p is 0 or 1; 
q is 0 or 1; and 
R.sup.4 and R.sup.6 are independently selected from the group consisting of 
hydrogen and C.sub.1-3 alkyl; 
##STR5## 
where R.sup.a, R.sup.b, and R.sup.c are independently selected from the 
group consisting of hydrogen and C.sub.1-6 alkyl; and 
R.sup.1 and R.sup.2 are independently hydrogen, halo, C.sub.1-6 alkoxy, 
C.sub.1-6 alkylthio, nitro, trifluoromethyl, or C.sub.1-6 alkyl; 
or a pharmaceutically acceptable salt or solvate thereof. These compounds 
have been shown to be very active, specific tachykinin receptor 
antagonists. Particularly preferred compounds are those of Formula II in 
which m and n are both 1; R.sup.1 and R.sup.2 are independently hydrogen, 
methoxy, ethoxy, chloro, fluoro, trifluoromethyl, methyl, and ethyl; Z is 
methylene; and Y, when combined with the heterocyclic group to which it is 
attached, forms 4-(piperidin-1-yl)piperidin-1-yl, 
4-(cyclohexyl)piperazin-1-yl, 4-(phenyl)piperaiin-1-yl, or 4 
(phenyl)piperidin-1-yl. 
Especially preferred is the compound (R)-3-(1 
H-indol-3-yl)1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-yl 
)piperidin-1-yl)acetyl)amino]propane and the pharmaceutically acceptable 
salts and solvates thereof. Most especially preferred is the compound 
(R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4(piperidin-1-yl 
)piperidin-1-yl)acetyl)amino]propane dihydrochloride trihydrate. 
The most preferred method of synthesizing this compound is depicted in 
Scheme I, infra. Many of the steps of this synthesis are described in 
Patent Cooperation Treaty Publication WO 95/14017, published May 26, 1995, 
and European Patent Application Publication 693,489, published Jan. 24, 
1996. 
##STR6## 
Synthesis of (R)-2-[N-(2-((4-cyclohexyl)piperazin-1-yl)acetyl)amino]-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane 
##STR7## 
(a) Preparation of (R)-3-(1 
H-indol-3-yl)-2(N-triphenylmethylamino)propanoic acid [N-trityltryptophan] 
Tritylation 
##STR8## 
Chlorotrimethylsilane (70.0 ml, 0.527 mol) was added at a moderate rate to 
a stirred slurry of D-tryptophan (100.0 g, 0.490 mol) in anhydrous 
methylene chloride (800 ml) under a nitrogen atmosphere. This mixture was 
continuously stirred for 4.25 hours. Triethylamine (147.0 ml, 1.055 mol) 
was added, followed by the addition of a solution of triphenylmethyl 
chloride (147.0 g, 0.552 mol) in methylene chloride (400 ml) using an 
addition funnel. The mixture was stirred at room temperature, under a 
nitrogen atmosphere for at least 20 hours. The reaction was quenched by 
the addition of methanol (500 ml). 
The solution was concentrated on a rotary evaporator to near dryness and 
the mixture was redissolved in methylene chloride and ethyl acetate. An 
aqueous work-up involving a 5% citric acid solution (2.times.) and brine 
(2.times.) was then performed. The organic layer was dried over anhydrous 
sodium sulfate, filtered, and concentrated to dryness on a rotary 
evaporator. The solid was dissolved in hot diethyl ether followed by the 
addition of hexanes to promote crystallization. By this process 173.6 g 
(0.389 mol) of analytically pure 
(R)-3-(lH-indol-3-yl)-2-(N-triphenylmethylamino)propanoic acid was 
isolated as a white solid in two crops giving a total of 79% yield. 
FDMS 446 (M.sup.+). 
.sup.1 H NMR (DMSO-d.sub.6).delta.2.70 (m, 1 H), 2.83 (m, 2 H), 3.35 (m, 1 
H), 6.92-7.20 (m, 12 H), 7.30-7.41 (m, 8 H), 10.83 (s, 1 H), 11.73 (br s, 
1 H). 
Analysis for C.sub.30 H.sub.26 N.sub.2 O.sub.2 : 
Theory: C, 80.69; H, 5.87; N, 6.27. 
Found: C, 80.47; H, 5.92; N, 6.10. 
(b) Preparation of (R)-3-(1 
H-indol-3-yl)-N-(2-methoxybenzyl)-2-(N-triphenylmethylamino)propanamide 
Coupling 
##STR9## 
To a stirred solution of (R)-3-(1 
H-indol-3-yl)-2-(N-triphenylmethylamino)propanoic acid (179.8 g, 0.403 
mol), 2-methoxybenzylamine (56.0 ml, 0.429 mol), and hydroxybenzotriazole 
hydrate (57.97 g, 0.429 mol) in anhydrous tetrahydrofiran (1.7 L) and 
anhydrous NN-dimethylformamide (500 ml) under a nitrogen atmosphere at 
0.degree. C., were added triethylamine (60.0 ml, 0.430 mol) and 
1-(3-dimethylaminopropyl)-3-ethoxycarbodiimide hydrochloride (82.25 g, 
0.429 mol). The mixture was allowed to warm to room temperature under a 
nitrogen atmosphere for at least 20 hours. The mixture was concentrated on 
a rotary evaporator and then redissolved in methylene chloride and an 
aqueous work-up of 5% citric acid solution (2.times.), saturated sodium 
bicarbonate solution (2.times.), and brine (2.times.) was performed. The 
organic layer was dried over anhydrous sodium sulfate and concentrated to 
dryness on a rotary evaporator. The desired product was then 
recrystallized from hot ethyl acetate to yield 215.8 g (0.381 mol, 95%) of 
analytically pure material. 
5 FDMS 565 (M+). 
.sup.1 H NMR (CDCl.sub.3).delta. 2.19 (dd, J=6.4 Hz, .DELTA.v=14.4 Hz, 1 
H), 2.64 (d, J=6.5 Hz, 1 H), 3.19 (dd, J=4.3 Hz, .DELTA.v=14.4 Hz, 1 H), 
3.49 (m, 1 H), 3.63 (s, 3 H), 3.99 (dd, J=5.4 Hz, .DELTA.v=14.2 Hz, 1 H), 
4.25 (dd, J=7.1 Hz, .DELTA.v=14.2 Hz, 1 H), 6.64 (d, J=2.1 Hz, 1 H), 6.80 
(d, J=8.2 Hz, 1 H), 6.91 (t, J=7.4 Hz, 1 H), 7.06-7.38 (m, 21 H), 7.49 (d, 
J=7.9 Hz, 1 H), 7.75 (s, 1 H). 
Analysis for C.sub.38 H.sub.35 N.sub.3 O.sub.2 : 
Theory: C, 80.68; H, 6.24; N, 7.43. 
Found: C, 80.65; H, 6.46; N, 7.50. 
(c) Preparation of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)amino]-2-(N-triphenylmethylanmino)prop 
ane 
Reduction of Carbonyl 
##STR10## 
RED-AL.RTM., [a 3.4 M, solution of sodium bis(2-methoxyethoxy)aluminum 
hydride in toluene] (535 ml, 1.819 mol), dissolved in anhydrous 
tetrahydrofuran (400 ml) was slowly added using an addition funnel to a 
refluxing solution of the acylation product, (R)-3-(1 
H-indol-3-yl)-N-(2-methoxybenzyl)-2-(N-triphenylmethylamnino)propanamide 
(228.6 g, 0.404 mols) produced supra, in anhydrous tetrahydrofuran (1.0 L) 
under a nitrogen atmosphere. The reaction mixture became a purple 
solution. The reaction was quenched after at least 20 hours by the slow 
addition of excess saturated Rochelle's salt solution (potassium sodium 
tartrate tetrahydrate). The organic layer was isolated, washed with brine 
(2.times.), dried over anhydrous sodium sulfate, filtered, and 
concentrated to an oil on a rotary evaporator. No further purification was 
done and the product was used directly in the next step. 
(d) Preparation of 
(R)-3-(lH-indol-3-yl)-1-[N-(2-methoxybenzyl)-acetylamino]-2-(N-triphenylme 
thylamino)propane 
Acylation of Secondary Amine 
##STR11## 
To a stirring solution of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)amino]-2-(N-triphenylmethylamino)propa 
ne (0.404 mol) in anhydrous tetrahydrofuran (1.2 L) under a nitrogen 
atmosphere at 0.degree. C. was added triethylamine (66.5 ml, 0.477 mol) 
and acetic anhydride (45.0 ml, 0.477 mol). After 4 hours, the mixture was 
concentrated on a rotary evaporator, redissolved in methylene chloride and 
ethyl acetate, washed with water (2.times.) and brine (2.times.), dried 
over anhydrous sodium sulfate, filtered, and concentrated to a solid on a 
rotary evaporator. The resulting solid was dissolved in chloroform and 
loaded onto silica gel 60 (230-400 mesh) and eluted with a 1:1 mixture of 
ethyl acetate and hexanes. The product was then crystallized from an ethyl 
acetate/hexanes mixture. The resulting product of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-(N-triphenylmethylamino 
)propane was crystallized and isolated over three crops giving 208.97 grams 
(87% yield) of analytically pure material. 
Analysis for C.sub.40 H.sub.39 N.sub.3 O.sub.2 : 
Theory: C, 80.91; H, 6.62; N, 7.08. 
Found: C, 81.00; H, 6.69; N, 6.94. 
(e) Preparation of (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane 
Deprotection 
##STR12## 
Formic acid (9.0 ml, 238.540 mmol) was added to a stirring solution of 
(R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-(N-triphenylmethylamino 
)propane (14.11 g, 23.763 mmol) in anhydrous methylene chloride under a 
nitrogen atmosphere at 0.degree. C. After 4 hours, the reaction mixture 
was concentrated to an oil on a rotary evaporator and redissolved in 
diethyl ether and 1.0 N hydrochloric acid. The aqueous layer was washed 
twice with diethyl ether and basified with sodium hydroxide to a pH 
greater than 12. The product was extracted out with methylene chloride 
(4.times.). The organic extracts were combined, dried over anhydrous 
sodium sulfate, filtered, and concentrated on a rotary evaporator to a 
white foam. The compound (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane (7.52 g, 21.397 
mmols) was isolated giving a 90% yield. No further purification was 
necessary. 
(f) Preparation of (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane dihydrochloride 
##STR13## 
A stirring solution of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-(N-triphenylmethylamino 
)propane in two volumes of methylene chloride was cooled to between 
-40.degree. C. and -50.degree. C. Anhydrous hydrogen chloride gas was 
added at such a rate that the temperature of the reaction mixture did not 
exceed 0.degree. C. The reaction mixture was stirred for 30 minutes to one 
hour at 0-10.degree. C. 
To this reaction mixture was added two volumes of methyl t-butyl ether and 
the resulting mixture was allowed to stir for 30 minutes to one hour at 
0-10.degree. C. The resulting crystalline solid was removed by filtration 
and then washed with methyl t-butyl ether. The reaction product was dried 
under vacuum at 50.degree. C. (Yield&gt;98%) 
Analysis for C.sub.21 H.sub.25 N.sub.3 O.sub.2 .multidot.2 HCl: 
Theory: C, 59.44; H, 6.41; N, 9.90. 
Found: C, 60.40; H, 6.60; N, 9.99. 
(g) Preparation of 2-((4-cyclohexyl)piperazin-1-yl)acetic acid potassium 
salt hydrate 
Cyclohexylpiperazine (10.0 g, 0.059 mol) was added to ten volumes of 
methylene chloride at room temperature. To this mixture was added sodium 
hydroxide (36 ml of a 2 N solution, 0.072 mol) and tetrabutylammonium 
bromide (1.3 g, 0.004 mol). After the addition of the sodium hydroxide and 
tetrabutylammonium bromide, methyl bromoacetate (7.0 ml, 0.073 mol) was 
added and the reaction mixture was stirred for four to six hours. The 
progress of the reaction was monitored by gas chromatography. 
The organic fraction was separated and the aqueous phase was back-extracted 
with methylene chloride. The organic phases were combined and washed twice 
with deionized water, once with saturated sodium bicarbonate solution, and 
then with brine. The organic phase was dried over magnesium sulfate and 
the solvents were removed in vacuo to yield methyl 
2-((4cyclohexyl)piperazin-1-yl)acetate as a yellowish oil. 
The title compound was prepared by dissolving the methyl 
2-((4-cyclohexyl)piperazin-1-yl)acetate (10.0 g, 0.042 mol) in ten volumes 
of diethyl ether. This solution was cooled to 15.degree. C. and then 
potassium trimethylsilanoate (5.9 g, 0.044) was added. This mixture was 
then stirred for four to six hours. The reaction product was removed by 
filtration, washed twice with five volumes of diethyl ether, then washed 
twice with five volumes of hexanes, and then dried in a vacuum oven for 
12-24 hours at 50.degree. C. 
Analysis for C.sub.12 H.sub.21 KN.sub.2 O.sub.2 .multidot.1.5 H.sub.2 O: 
Theory: C, 49.63; H, 7.98; N, 9.65. 
Found: C, 49.54; H, 7.72; N, 9.11. 
(h) Preparation of 
(R)-2-[N-(2-((4-cyclohexyl)piperazin-1-yl)acetyl)amino]-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane 
The title compound was prepared by first cooling 
2-((4-cyclohexyl)piperazin-1-yl)acetic acid potassium salt to a 
temperature between -8.degree. C. and -15.degree. C. in 5 volumes of 
anhydrous methylene chloride. To this mixture was added 
isobutylchloroformate at a rate such that the temperature did not exceed 
-8.degree. C. The resulting reaction mixture was stirred for about 1 hour, 
the temperature being maintained between -8.degree. C. and -15.degree. C. 
To this mixture was then added (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane dihydrochloride at 
such a rate that the temperature did not exceed 0.degree. C. Next added to 
this mixture was N-methyl morpholine at a rate such that the temperature 
did not exceed 0.degree. C. This mixture was then stirred for about 1 hour 
at a temperature between -15.degree. C. and -8.degree. C. 
The reaction was quenched by the addition of 5 volumes of water. The 
organic layer was washed once with a saturated sodium bicarbonate 
solution. The organic phase was then dried over anhydrous potassium 
carbonate and filtered to remove the drying agent. To the filtrate was 
then added 2 equivalents of concentrated hydrochloric acid, followed by 1 
volume of isopropyl alcohol. The methylene chloride was then exchanged 
with isopropyl alcohol under vacuum by distillation. 
The final volume of isopropyl alcohol was then concentrated to three 
volumes by vacuum. The reaction mixture was cooled to 20.degree. C. to 
25.degree. C. and the product was allowed to crystallize for at least one 
hour. The desired product was then recovered by filtration and washed with 
sufficient isopropyl alcohol to give a colorless filtrate. The crystal 
cake was then dried under vacuum at 50.degree. C. MS 560 (M+1.sup.+). 
.sup.1 H NMR (CDCl.sub.3).delta. 1.09-1.28 (m, 5 H), 1.64 (d, J=10 Hz, 1 
H), 1.80-1.89 (m, 4 H), 2.10 (s, 3H), 2.24-2.52 (m, 9 H), 2.90 (s, 2 H), 
2.95 (d, J=7 Hz, 1 H), 3.02 (d, J=7 Hz, 1 H), 3.12 (dd, J=5, 14 Hz, 1 H), 
3.77 (s, 3 H), 4.01 (dd, J=10, 14 Hz, 1 H), 4.49 (ABq, J=17 Hz, 43 Hz, 2 
H), 4.56 (m, 1 H), 6.79-6.87 (m, 3 H), 7.05-7.24 (m, 4 H), 7.34-7.41 (m, 2 
H), 7.67 (d, J=8 Hz, 1 H), 8.22 (s, 1 H). 
Analysis for C.sub.33 H.sub.45 N.sub.5 O.sub.3 : 
Theory: C, 70.81; H, 8.10; N, 12.51. 
Found: C, 70.71; H, 8.21; N, 12.42. 
Synthesis of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-y 
l)piperidin-1-yl)acetyl)amino]propane 
##STR14## 
(a) Preparation of 2-(4-(piperidin-1-yl)piperidin-1-yl)acetic acid, 
potassium salt 
4-(Piperidin-1-yl)piperidine (1.20 kg, 7.13 mol) was added to methylene 
chloride (12.0 L) under a nitrogen atmosphere. Tetrabutylammonium bromide 
(0.150 kg, 0.47 mol) and sodium hydroxide (1.7 L of a 5 N solution, 8.5 
mol) were then added. The reaction mixture was cooled to 10-15.degree. C. 
and methyl bromoacetate (1.17 kg, 7.65 mol) was added and the resulting 
mixture was stirred for a minimum of 16 hours. 
Deionized water (1.2 L) was then added to the mixture and the layers 
separated. The aqueous layer was back-extracted with methylene chloride 
(2.4 L). The organic fractions were combined and washed with deionized 
water (3.times.1.2 L), a saturated sodium bicarbonate solution (1.1 L) and 
a saturated sodium chloride solution (1.1 L). The organic fraction was 
then dried over anhydrous magnesium sulfate and concentrated to an oil on 
a rotary evaporator to yield 1.613 kg (93.5%) of methyl 
2-(4-(piperidin-1-yl)piperidin-1-yl)acetate. 
A solution of methyl 2-[4-(piperidin-1-yl)piperidin-1-yl]acetate (2.395 kg, 
9.96 mol) in methanol (2.4 L) was added to a solution of potassium 
hydroxide (0.662 kg, 10.0 mol @ 85% purity) in methanol (10.5 L) under a 
nitrogen atmosphere. The reaction mixture was heated to 45-50.degree. C. 
for a minimum of 16 hours. 
A solvent exchange from methanol to acetone (15.0 L) was performed on the 
solution on a rotary evaporator. This solution was slowly cooled to room 
temperature over 16 hours. The resulting solids were filtered, rinsed with 
acetone (5.0 L) and then dried to yield 2.471 kg (93.8%) of 
2-(4-(piperidin-1-yl)piperidin-1-yl)acetic acid, potassium salt. MS 265 
(M.sup.+1) 
(b) Preparation of 
(R)-3-(lH-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piper 
idin-1-yl)piperidin-1-yl)acetyl)amino]propane 
The title compound was prepared by first admixing 
(R)-2-amino-3-(1H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane 
dihydrochloride (50.0 g, 0.118 mol) with 100 ml of methylene chloride 
under a nitrogen atmosphere. 
In a second flask, under a nitrogen atmosphere, 
2-(4-(piperidin-1-yl)piperidin-1-yl)acetic acid potassium salt (62.3 g, 
0.236 mol) was added to 600 ml of methylene chloride. This mixture was 
cooled to about -10.degree. C. and stirring was continued. To this mixture 
isobutylchloroformate (23 ml, 0.177 mol) was added dropwise such that the 
temperature of the 2(4-(piperidin-1-yl)piperidin-1-yl)acetic acid 
potassium salt mixture never rose appreciably. 
This reaction mixture was stirred at about -10.degree. C. for about 1.5 
hours at which time the (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane 
dihydrochloride/methylene chloride mixture prepared supra was slowly added 
to the 2-(4-(piperidin-1-yl)piperidin-1-yl)acetic acid potassium 
salt/isobutylchloroformate/methylene chloride solution. The resulting 
mixture was then stirred for about 1 hour at a temperature between 
-15.degree. C. and -8.degree. C. 
The reaction mixture was removed from the ice bath and allowed to warm to 
15-20.degree. C. and the reaction was quenched by the addition of 200 ml 
of water. The pH of the solution was adjusted to 2.3-2.7 by the additon of 
1 N sulfuric acid. The layers were separated and the aqueous layer was 
washed with 100 ml of methylene chloride. 
The organic fractions were combined and washed with water (100 ml). The 
water wash was back extracted with methylene chloride (50 ml) and combined 
with the aqueous fraction from above. Methylene chloride (500 ml) was 
added to the combined aqueous layers and the mixture was stirred at room 
temperature for 15 minutes as basification with 2 N sodium hydroxide to a 
final pH of 9.8 to 10.2 was achieved. 
The organic and aqueous fractions were separated. The aqueous fraction was 
washed with methylene chloride and the methylene chloride was added to the 
organic fraction. The organic fraction was then washed with a mixture of 
saturated sodium bicarbonate solution (100 ml) and water (50 ml). The 
bicarbonate wash was separated from the organic fraction and back 
extracted with methylene chloride (50 ml). The back extraction was 
combined with the methylene chloride fraction and the combined fractions 
were dried over magnesium sulfate. The magnesium sulfate was removed by 
filtration and the volatiles were removed by vacuum distillation to yield 
the title product as a foam. (72.5 g, &gt;98% yield). MS 559(M.sup.+1) 
NMR (DMSO-d.sub.6 3:2 mixture of amide rotamers) .delta.1.25-1.70 (m, 10 
H), 1.77-2.00 (m, 2H), 1.95 (s, 3/5.3 H), 2.04 (s, 2/5.multidot.3 H), 
2.10-2.97 (m, 9 H), 3.10-3.65 (m, 3 H), 3.72 (s, 2/5.multidot.3 H), 3.74 
(s, 3/5.multidot.3 H), 4.26-4.58 (m, 3 H), 6.76-7.12 (m, 6H), 7.13-7.35 
(m, 2 H), 7.42-7.66 (m, 2 H), 10.80 (br s, 1 H). 
Analysis for C.sub.33 H.sub.45 N.sub.5 O.sub.3 : 
Theory: C, 70.81; H, 8.10; N, 12.51. 
Found: C, 70.57; H, 8.05; N, 12.39. 
An alternative process for preparing the compounds of Formula I follows. 
Preparation of (R)-3-(1 H-indol-3-yl)-2-(N-triphenylmethylamino)propanoic 
acid, N-methylmopholine salt (N-trityl-D-tryptophan N-methylmopholine 
salt). 
##STR15## 
To a one liter 4 neck flask equipped with mechanical stirrer, condenser, 
probe, and stopper, were added D-tryptophan (40.0 g, 0.196 mol), 
acetonitrile (240 ml), and 1,1,1,3,3,3-hexamethyldisilazane (39.5 g, 0.245 
mol). The resulting mixture was heated to 50-60.degree. C. and stirred 
until homogeneous. In a separate beaker trityl chloride (60.06 g, 0.215 
mol) and acetonitrile (120 ml) were slurried. The slurry was added to the 
silylated tryptophan mixture and the beaker was rinsed with 40 ml of 
acetonitrile. To the reaction mixture N-methylmorpholine (23.7 ml, 21.8 g, 
0.216 mol) was added and the resulting mixture was stirred for one hour. 
The progress of the reaction was monitored by chromatography. 
After satisfactory progress, water (240 ml) was added dropwise to the 
reaction mixture and the resulting mixture was cooled to less than 
10.degree. C., stirred for thirty minutes, and filtered. The residue was 
washed with water, and then dried to obtain 108.15 grams (&gt;99% yield) of 
the desired title product. 
.sup.1 H NMR (DMSO-d.sub.6).delta. 2.70 (m, 1 H), 2.83 (m, 2 H), 3.35 (m, 1 
H), 6.92-7.20 (m, 12 H), 7.30-7.41 (m, 8 H), 10.83 (s, 1 H), 11.73 (br s, 
1 H). 
Analysis for C.sub.30 H.sub.26 N.sub.2 O.sub.2 : 
Theory: C, 80.69; H, 5.87; N, 6.27. 
Found: C, 80.47; H, 5.92; N, 6.10. 
Preparation of (R)-3-(1 
H-indol-3-yl)-N-(2-methoxybenzyl)-2-(N-triphenylmethylamino)propanamide. 
##STR16## 
To a two liter 4 neck flask equipped with mechanical stirrer, condensor, 
and thermocouple, under a nitrogen atmosphere, were added 
N-trityl-D-tryptophan N-methylmopholine salt (108.0 g, 0.196 mol), 
acetonitrile (800 ml), 2-chloro-4,6-dimethoxy-1,3,5-triazine (38.63 g, 
0.22 mol), and N-methylmorpholine (29.1 ml). The resulting mixture was 
stirred at ambient temperature until homogeneous (about ten minutes). 
After about one hour, 2-methoxybenzylamine (29 ml) was added. The resulting 
mixture was heated to 35.degree. C. and maintained at that temperature 
overnight. The progress of the reaction was monitored by chromatography. 
Water (750 ml) was then added dropwise to the reaction mixture and the 
resulting mixture was cooled to less than 10.degree. C., stirred for 
thirty minutes, and filtered. The residue was washed with water (about 100 
ml), and then dried to obtain the desired title product. (Yield: 87% and 
91% in two runs) FDMS 565 (M.sup.+). 
.sup.1 H NMR (CDCl.sub.3).delta. 2.19 (dd, J=6.4 Hz, .DELTA.v=14.4 Hz, 1 
H), 2.64 (d, J=6.5 Hz, 1 H), 3.19 (dd, J=4.3 Hz, .DELTA.v=14.4 Hz, 1 H), 
3.49 (m, 1 H), 3.63 (s, 3 H), 3.99 (dd, J=5.4 Hz, .DELTA.v=14.2 Hz, 1 H), 
4.25 (dd, J=7.1 Hz, .DELTA.v=14.2 Hz, 1 H), 6.64 (d, J=2.1 Hz, 1 H), 6.80 
(d, J=8.2 Hz, 1 H), 6.91 (t, J=7.4 Hz, 1 H), 7.06-7.38 (m, 21 H), 7.49 (d, 
J=7.9 Hz, 1 H), 7.75 (s, 1 H). 
Analysis for C.sub.38 H.sub.35 N.sub.3 O.sub.2 : 
Theory: C, 80.68; H. 6.24; N. 7.43. 
Found: C, 80.65; H. 6.46; N. 7.50. 
Reduction of Carbonyl 
##STR17## 
Preparation of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)amino]-2-(N-triphenylmethylamino)propa 
ne 
RED-AL.RTM., [a 3.4 M, solution of sodium bis(2-methoxyethoxy)aluminum 
hydride in toluene] (535 ml, 1.819 mol), dissolved in anhydrous 
tetrahydrofuran (400 ml) was slowly added using an addition funnel to a 
refluxing solution of the acylation product, (R)-3-(1 
H-indol-3-yl)-N-(2-methoxybenzyl)-2-(N-triphenylmethylamino)propanamide 
(228.6 g, 0.404 mols) produced supra, in anhydrous tetrahydrofuiran (1.0 
L) under a nitrogen atmosphere. The reaction mixture became a purple 
solution. The reaction was quenched after at least 20 hours by the slow 
addition of excess saturated Rochelle's salt solution (potassium sodium 
tartrate tetrahydrate). The organic layer was isolated, washed with brine 
(2.times.), dried over anhydrous sodium sulfate, filtered, and 
concentrated to an oil on a rotary evaporator. No further purification was 
done and the product was used directly in the next step. 
Acylation of Secondary Amine 
##STR18## 
Preparation of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)-acetylamino]-2-(N-triphenylmethylamin 
o)propane 
To a stirring solution of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)amino]-2-(N-triphenylmethylanmino)prop 
ane (0.404 mol) in anhydrous tetrahydrofuran (1.2 L) under a nitrogen 
atmosphere at 0.degree. C. was added triethylamine (66.5 ml, 0.477 mol) 
and acetic anhydride (45.0 ml, 0.477 mol). After 4 hours, the mixture was 
concentrated on a rotary evaporator, redissolved in methylene chloride and 
ethyl acetate, washed with water (2.times.) and brine (2.times.), dried 
over anhydrous sodium sulfate, filtered, and concentrated to a solid on a 
rotary evaporator. The resulting solid was dissolved in chloroform and 
loaded onto silica gel 60 (230-400 mesh) and eluted with a 1:1 mixture of 
ethyl acetate and hexanes. The product was then crystallized from an ethyl 
acetate/hexanes mixture. The resulting product of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-(N-triphenylmethylamino 
)propane was crystallized and isolated over three crops giving 208.97 grams 
(87% yield) of analytically pure material. 
Analysis for C.sub.40 H.sub.39 N.sub.3 O.sub.2 : 
Theory: C, 80.91; H, 6.62; N, 7.08. 
Found: C, 81.00; H, 6.69; N, 6.94. 
Deprotection 
##STR19## 
Preparation of (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane dihydrochloride 
A stirring solution of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-(N-triphenylmethylamino 
)propane in two volumes of methylene chloride was cooled to between 
-40.degree. C. and -50.degree. C. Anhydrous hydrogen chloride gas was 
added at such a rate that the temperature of the reaction mixture did not 
exceed 0.degree. C. The reaction mixture was stirred for 30 minutes to one 
hour at 0-10.degree. C. 
To this reaction mixture was added two volumes of methyl t-butyl ether and 
the resulting mixture was allowed to stir for 30 minutes to one hour at 
0-10.degree. C. The resulting crystalline solid was removed by filtration 
and then washed with methyl t-butyl ether. The reaction product was dried 
under vacuum at 50.degree. C. (Yield &gt;98%) 
Analysis for C.sub.21 H.sub.25 N.sub.3 O.sub.2 .multidot.2 HCl: 
Theory: C, 59.44; H, 6.41; N, 9.90. 
Found: C, 60.40; H, 6.60; N, 9.99. 
Preparation of 2-((4-cyclohexyl)piperazin-1-yl)acetic acid potassium salt 
hydrate 
Cyclohexylpiperazine (10.0 g, 0.059 mol) was added to ten volumes of 
methylene chloride at room temperature. To this mixture was added sodium 
hydroxide (36 ml of a 2 N solution, 0.072 mol) and tetrabutylammonium 
bromide (1.3 g, 0.004 mol). After the addition of the sodium hydroxide and 
tetrabutylammonium bromide, methyl bromoacetate (7.0 ml, 0.073 mol) was 
added and the reaction mixture was stirred for four to six hours. The 
progress of the reaction was monitored by gas chromatography. 
The organic fraction was separated and the aqueous phase was back-extracted 
with methylene chloride. The organic phases were combined and washed twice 
with deionized water, once with saturated sodium bicarbonate solution, and 
then with brine. The organic phase was dried over magnesium sulfate and 
the solvents were removed in vacuo to yield methyl 
2-((4-cyclohexyl)piperazin-1-yl)acetate as a yellowish oil. 
The title compound was prepared by dissolving the methyl 
2-((4-cyclohexyl)piperazin-1-yl)acetate (10.0 g, 0.042 mol) in ten volumes 
of diethyl ether. This solution was cooled to 15.degree. C. and then 
potassium trimethylsilanoate (5.9 g, 0.044) was added. This mixture was 
then stirred for four to six hours. The reaction product was removed by 
filtration, washed twice with five volumes of diethyl ether, then washed 
twice with five volumes of hexanes, and then dried in a vacuum oven for 
12-24 hours at 50.degree. C. 
Analysis for C.sub.12 H.sub.21 KN.sub.2 O.sub.2.1.5 H.sub.2 O: 
Theory: C, 49.63; H, 7.98; N, 9.65. 
Found: C, 49.54; H, 7.72; N, 9.11. 
Preparation of (R)-2-[N-(2-((4cyclohexyl)piperazin-1-yl)acetyl)amino]-3-(1 
H-indol-3-yl)- 1-[N-(2-methoxybenzyl)acetylamino]propane 
##STR20## 
The title compound was prepared by first cooling 
2-((4-cyclohexyl)piperazin-1-yl)acetic acid potassium salt to a 
temperature between -8.degree. C. and -15.degree. C. in 5 volumes of 
anhydrous methylene chloride. To this su e was added isobutyichioroformate 
at a rate such that the temperature did not exceed -8.degree. C. The 
resulting reaction mixture was stirred for about 1 hour, the temperature 
being maintained between -8.degree. C. and -15.degree. C. 
To this mixture was then added (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane dihydrochloride at 
such a rate that the temperature did not exceed 0.degree. C. Next added to 
this mixture was N-methyl morpholine at a rate such that the temperature 
did not exceed 0.degree. C. This mixture was then stirred for about 1 hour 
at a temperature between -15.degree. C. and -8.degree. C. 
The reaction was quenched by the addition of 5 volumes of water. The 
organic layer was washed once with a saturated sodium bicarbonate 
solution. The organic phase was then dried over anhydrous potassium 
carbonate and filtered to remove the drying agent. To the filtrate was 
then added 2 equivalents of concentrated hydrochloric acid, followed by 1 
volume of isopropyl alcohol. The methylene chloride was then exchanged 
with isopropyl alcohol under vacuum by distillation. 
The final volume of isopropyl alcohol was then concentrated to three 
volumes by vacuum. The reaction mixture was cooled to 20.degree. C. to 
25.degree. C. and the product was allowed to crystallize for at least one 
hour. The desired product was then recovered by filtration and washed with 
sufficient isopropyl alcohol to give a colorless filtrate. The crystal 
cake was then dried under vacuum at 50.degree. C. MS 560 (M+1.sup.+). 
.sup.1 NMR (CDCl.sub.3).delta. 1.09-1.28 (m, 5 H), 1.64 (d, J=10 Hz, 1H), 
1.80-1.89 (m, 4 H), 2.10 (s, 3 H), 2.24-2.52 (m, 9 H), 2.90 (s, 2 H), 2.95 
(d, J=7 Hz, 1 H), 3.02 (d, J=7 Hz, 1H), 3.12 (dd, J=5, 14 Hz, 1 H), 3.77 
(s, 3 H), 4.01 (dd, J=10, 14 Hz, 1 H), 4.49 (ABq, J=17 Hz, 43 Hz, 2 H), 
4.56 (m, 1 H), 6.79-6.87 (m, 3 H), 7.05-7.24 (m, 4 H), 7.34-7.41 (m, 2 H), 
7.67 (d, J=8 Hz, 1 H), 8.22 (s, 1 H). 
Analysis for C.sub.33 H.sub.45 N.sub.5 O.sub.3 : 
Theory: C, 70.81; H, 8.10; N, 12.51. 
Found: C, 70.71; H, 8.21; N, 12.42. 
Preparation of 2-(4-(piperidin-1-yl)piperidin-1-yl)acetic acid, potassium 
salt 
##STR21## 
4-(Piperidin-1-yl)piperidine (1.20 kg, 7.13 mol) was added to methylene 
chloride (12.0 L) under a nitrogen atmosphere. Tetrabutylammonium bromide 
(0.150 kg, 0.47 mol) and sodium hydroxide (1.7 L of a 5 N solution, 8.5 
mol) were then added. The reaction mixture was cooled to 10-15.degree. C. 
and methyl bromoacetate (1.17 kg, 7.65 mol) was added and the resulting 
mixture was stirred for a minimum of 16 hours. 
Deionized water (1.2 L) was then added to the mixture and the layers 
separated. The aqueous layer was back-extracted with methylene chloride 
(2.4 L). The organic fractions were combined and washed with deionized 
water (3.times.1.2 L), a saturated sodium bicarbonate solution (1.1 L) and 
a saturated sodium chloride solution (1.1 L). The organic fraction was 
then dried over anhydrous magnesium sulfate and concentrated to an oil on 
a rotary evaporator to yield 1.613 kg (93.5%) of methyl 
2-(4-(piperidin-1-yl)piperidin-1-yl)acetate. 
A solution of methyl 2-[4-(piperidin-1-yl)piperidin-1-yl]acetate (2.395 kg, 
9.96 mol) in methanol (2.4 L) was added to a solution of potassium 
hydroxide (0.662 kg, 10.0 mol @ 85% purity) in methanol (10.5 L) under a 
nitrogen atmosphere. The reaction mixture was heated to 45-50.degree. C. 
for a minimum of 16 hours. 
A solvent exchange from methanol to acetone (15.0 L) was performed on the 
solution on a rotary evaporator. This solution was slowly cooled to room 
temperature over 16 hours. The resulting solids were filtered, rinsed with 
acetone (5.0 L) and then dried to yield 2.471 kg (93.8%) of 
2-(4-(piperidin-1-yl)piperidin-1-yl)acetic acid, potassium salt. MS 265 
(M.sup.+1) 
Preparation of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-y 
l)piperidin-1-yl)acetyl)amino]propane dihydrochloride trihydrate 
##STR22## 
Under a nitrogen atmosphere 2-(4-(piperidin-1-yl)piperidin-1-yl)acetic 
acid, potassium salt (0.75 kg, 2.84 mol) was added to methylene chloride 
(7.5 L). The resulting mixture was cooled to -15 to -8.degree. C. and 
isobutyl chloroformate (0.29 kg, 2.12 mol) was added at such a rate so as 
to maintain the temperature of the reaction mixture below -8.degree. C. 
After the addition the resulting reaction mixture was stirred for 90 
minutes between -15 and -8.degree. C. 
The reaction mixture was then cooled to -35.degree. C. and solid 
(R)-2-amino-3-(1 H-indol-3-yl)-1-[N-(2-methoxybenzyl)amino]propane 
dihydrochloride (0.60 kg, 1.14 mol) was added at such a rate that the 
reaction temperature was maintained at less than -20.degree. C. After the 
addition, the reaction mixture was stirred for about one hour with the 
temperature being maintained between -37.degree. C. and -20.degree. C. The 
reaction was quenched by the addition of deionized water (7.5 L). The 
reaction mixture was basified to pH 12.8-13.2 by the addition of 5 N 
sodium hydroxide. The aqueous fraction was removed and retained. 
Additional deionized water (3.75 L) was added to the organic fraction as 
was sufficient 5 N sodium hydroxide to re-adjust the pH to 12.8-13.2. 
The two aqueous fractions were combined, back-extracted with methylene 
chloride (1.5 L) and then discarded. The organic fractions were combined 
and washed with deionized water (4.times.3.5 L). These extracts were 
combined, back-extracted with methylene chloride (1.5 L), and then 
discarded. The two organic layers were combined and washed with a 
saturated sodium chloride solution (3.7 L). 
The organic fraction was dried over anhydrous magnesium sulfate, filtered, 
and solvent exchanged from methylene chloride to acetone (3.75 L) on a 
rotary evaporator. An aqueous solution of hydrochloric acid (0.48 L of 6 N 
solution, 2.88 mol) and seed crystals (2 g) were added and mixture was 
stirred for 30-90 minutes. Acetone (13.2 L) was then added and the slurry 
stirred for one hour. The resulting solid was then filtered, washed with 
acetone (2-1.4 L), and dried to yield 633 g (90%) of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-y 
l)piperidin-1-yl)acetyl)amino]propane dihydrochloride trihydrate. 
Preparation of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-y 
l)piperidin-1-yl)acetyl)amino]propane dioxalate 
##STR23## 
Into a 500 ml jacketed round bottom flask was placed 
2-(4-(piperidin-1-yl)piperidin-1-yl)acetic acid, potassium salt (25.0 g, 
94.5 mmol) and 375 ml of N,N-dimethylformamide. The resulting slurry was 
cooled to -19.degree. C. and isobutylchloroformate (12.9 g, 94.5 mmol) was 
added over five minutes. The resulting mixture was stirred for twenty 
minutes and then (R)-2-amino-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]propane dihydrochloride 
(25.0 g, 58.1 mmol), dissolved in 75 ml of anhydrous 
N,N-dimethylformamide, was added over ten minutes. 
The resulting mixture is then cooled to 0.degree. C., stirred for about ten 
minutes, and then permitted to warm to room temperature. The progress of 
the reaction was monitored by chromatography. High performance liquid 
chromatography showed 99% conversion of the reactants after ninety 
minutes. 
The reaction mixture was partitioned between ethyl acetate (375 ml) and a 
saturated sodium bicarbonate solution (375 ml). The aqueous layer was back 
extracted with 375 ml of ethyl acetate. The organic fractions were 
combined, washed with water (3.times.375 ml), and then dried over 
magnesium sulfate. Potassium hydroxide is then added to the aqueous 
fraction from above and this resulting basified solution is extracted with 
ethyl acetate. This organic fraction is then dried over magnesium sulfate. 
The combined dried organic fractions are then treated with a concentrated 
oxalic acid solution. The resulting solids are filtered and dried at 
50.degree. C. om a vacuum oven to yield 23.5 grams of the desired 
intermediate. 
As would be appreciated by a skilled practitioner the mixed anhydride 
process will work in a number of organic solvents, in addition to the 
anhydrous N,N-dimethylformamide depicted above. Representative examples of 
solvents which may be employed include acetonitrile, tetrahydrofuran, 
dichloromethane. The mixed anhydride process can be performed at 
temperatures below 0.degree. C. 
The oxalate can be isolated from ethyl acetate as well as from other 
solvents, probably including acetone, acetonitrile, and t-butyl methyl 
ether. The use of oxalic acid is, however, very important for the 
precipitation as a large number of acids do not give a precipitate. Among 
those acids attempted, but found not satisfactory for the processes of the 
present invention, are citric, anhydrous hydrochloric, tartaric, mandelic, 
trifluoroacetic, p-nitrobenzoic, phenoxyacetic, maleic, fumaric, glutaric, 
adipic, methanesulfonic, p-toluenesulfonic, pamoic, trans-1,2-cyclohexane 
dicarboxylic, succinic, phthalic, 
trans-1,2-diaminocyclohexane-N,N,N',N'-naphthalenedisulfonic, and 
5-sulfosalicylic acids. Only oxalic acid and 1,5-naphthalene disulfonic 
acid reproducibly produced a solid. 
Preparation of (R)-3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-y 
l)piperidin-1-yl)acetyl)amino]propane dihydrochloride trihydrate 
##STR24## 
Into a large beaker were added (R)-3-(1 
H-indol-3-yl)1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-yl 
)piperidin-1-yl)acetyl)amino]propane dioxalate (13.4 g, 18.1 mmol), 
methylene chloride (58.16 ml, 78.51 g), and water (118.59 ml). The 
resulting mixture was stirred and the pH of the reaction mixture was 
adjusted to 10-12 using 50% caustic. 
The phases were separated and the organic phase was back extracted with 
water (101.44 ml). The organic fraction was transferred to a jacketed 
round bottom flask and a solvent exchange was performed using about 23 
volumes of acetone. Portions of the acetone were added to the product 
solution and the amount added was distilled away. The progress of the 
solvent exchange was monitored by NMR. The amount of desired product was 
monitored by high performance liquid chromatography. 
Enough water was added to bring the water concentration to eleven percent 
and the resulting mixture was heated to 55.degree. C. Enough concentrated 
hydrochloric acid was added to lower the pH to 2.0 and the reaction 
mixture was then permitted to cool to 37.degree. C. over 45 minutes. 
The product solution was seeded and permitted to stir for 10-30 minutes. 
The product solution was cooled to 19.degree. C. over two hours and 
acetone (ten equivalent volumes) was added over three hours, after which 
time the reaction mixture was stirred for one to three hours, maintaining 
the temperature at 19.degree. C. The product solution was filtered and the 
residue was washed with 6.67 equivalents of acetone. The residue was then 
dried in a vacuum oven at 42.degree. C. to give the desired title product. 
The other compounds of Formula I may be prepared essentially as described 
above, employing corresponding starting materials. 
The biological efficacy of a compound believed to be effective as a 
tachykinin receptor antagonist may be confirmed by employing an initial 
screening assay which rapidly and accurately measured the binding of the 
tested compound to known NK-1 and NK-2 receptor sites. Assays useful for 
evaluating tachykinin receptor antagonists are well known in the art. See. 
e.g., J. Jukic, et al., Life Sciences 49:1463-1469 (1991); N. Kucharczyk, 
et al., Journal of Medicinal Chemistry, 36:1654-1661 (1993); N. Rouissi, 
et al., Biochemical and Biophysical Research Communications 176:894-901 
(1991). 
NK-1 Receptor Binding Assay 
Radioreceptor binding assays were performed using a derivative of a 
previously published protocol. D. G. Payan, et al., Journal of Immunology, 
133:3260-3265 (1984). In this assay an aliquot of IM9 cells 
(1.times.10.sup.6 cells/tube in RPMI 1604 medium supplemented with 10% 
fetal calf serum) was incubated with 20 pM .sup.125 I-labeled substance P 
in the presence of increasing competitor concentrations for 45 minutes at 
4.degree. C. 
The IM9 cell line is a well-characterized cell line which is readily 
available to the public. See. e.g., Annals of the New York Academy of 
Science, 190: 221-234 (1972); Nature (London), 251:443-444 (1974); 
Proceedings of the National Academy of Sciences (USA) 71:84-88 (1974). 
These cells were routinely cultured in RPMI 1640 supplemented with 50 
.mu.g/ml gentamicin sulfate and 10% fetal calf serum. 
The reaction was terminated by filtration through a glass fiber filter 
harvesting system using filters previously soaked for 20 minutes in 0.1% 
polyethylenimine. Specific binding of labeled substance P was determined 
in the presence of 20 nM unlabeled ligand. 
Many of the compounds employed in the methods of the present invention are 
also effective antagonists of the NK-2 receptor. 
NK-2 Receptor Binding Assay 
The CHO-hNK-2R cells, a CHO-derived cell line transformed with the human 
NK-2 receptor, expressing about 400,000 such receptors per cell, were 
grown in 75 cm.sup.2 flasks or roller bottles in minimal essential medium 
(alpha modification) with 10% fetal bovine serum. The gene sequence of the 
human NK-2 receptor is given in N. P. Gerard, et al., Journal of 
Biological Chemistry 265:20455-20462 (1990). 
For preparation of membranes, 30 confluent roller bottle cultures were 
dissociated by washing each roller bottle with 10 ml of Dulbecco's 
phosphate buffered saline (PBS) without calcium and magnesium, followed by 
addition of 10 ml of enzyme-free cell dissociation solution (PBS-based, 
from Specialty Media, Inc.). After an additional 15 minutes, the 
dissociated cells were pooled and centrifuged at 1,000 RPM for 10 minutes 
in a clinical centrifuge. Membranes were prepared by homogenization of the 
cell pellets in 300 ml 50 mM Tris buffer, pH 7.4 with a Tekmar.RTM. 
homogenizer for 10-15 seconds, followed by centrifugation at 12,000 RPM 
(20,000 .times.g) for 30 minutes using a Beckman JA-14.RTM. rotor. The 
pellets were washed once using the above procedure. and the final pellets 
were resuspended in 100-120 ml 50 mM Tris buffer, pH 7.4, and 4 ml 
aliquots stored frozen at -70.degree. C. The protein concentration of this 
preparation was 2 mg/ml. 
For the receptor binding assay, one 4-ml aliquot of the CHO-hNK-2R membrane 
preparation was suspended in 40 ml of assay buffer containing 50 mM Tris, 
pH 7.4, 3 mM manganese chloride, 0.02% bovine serum albumin (BSA) and 4 
.mu.g/ml chymostatin. A 200 .mu.l volume of the homogenate (40 .mu.g 
protein) was used per sample. The radioactive ligand was [.sup.125 
I]iodohistidyl-neurokinin A (New England Nuclear, NEX-252), 2200 Ci/mmol. 
The ligand was prepared in assay buffer at 20 nCi per 100 .mu.l; the final 
concentration in the assay was 20 pM. Non-specific binding was determined 
using 1 .mu.M eledoisin. Ten concentrations of eledoisin from 0.1 to 1000 
n-M were used for a standard concentration-response curve. 
All samples and standards were added to the incubation in 10 .mu.l 
dimethylsulfoxide (DMSO) for screening (single dose) or in 5 .mu.l DMSO 
for IC.sub.50 determinations. The order of additions for incubation was 
190 or 195 .mu.assay buffer, 200 .mu.l homogenate, 10 or 5 .mu.l sample in 
DMSO, 100 .mu.l radioactive ligand. The samples were incubated 1 hr at 
room temperature and then filtered on a cell harvester through filters 
which had been presoaked for two hours in 50 mM Tris buffer, pH 7.7, 
containing 0.5% BSA. The filter was washed 3 times with approximately 3 ml 
of cold 50 mM Tris buffer, pH 7.7. The filter circles were then punched 
into 12.times.75 mm polystyrene tubes and counted in a gamma counter. 
The compounds of Formula I are useful in treating sleep apnea. The 
effectiveness of a compound employed in the present invention may be 
demonstrated using standard techniques. U.S. Pat. No. 5,422,374, issued 
Jun. 6, 1995, the entire contents of which are herein incorporated by 
reference, describes a typical study to examine the effectiveness of a 
compound in treating sleep apnea. 
Sleep Study Example 1 
Ten patients of sleep apnea are given a soft capsule containing 10 mg of 
(R)3-(1 
H-indol-3-yl)-1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperidin-1-y 
l)piperidin-1-yl)acetyl)amino]propane dihydrochloride trihydrate before 
bed. Observation of the patients during sleep reveals no apneic symptoms. 
Moreover, no feelings of mailaise in daytime are observed. 
Sleep Study Example 2 
The patients who have been diagnosed with sleep apnea are given soft 
capsules, each containing 10 mg of 
(R)-3-(lH-indol-3-yl)1-[N-(2-methoxybenzyl)acetylamino]-2-[N-(2-(4-(piperi 
din-1-yl)piperidin-1-yl)acetyl)amino]propane dihydrochloride trihydrate at 
a dose of one capsule after supper for period of days. Clinical symptoms 
of the patients are observed, and apnea index (times/hour) are also 
measured before and after administration. 
While it is possible to administer a compound employed in the methods of 
this invention directly without any formulation, the compounds are usually 
administered in the form of pharmaceutical compositions comprising a 
pharmaceutically acceptable excipient and at least one active ingredient. 
These compositions can be administered by a variety of routes including 
oral, rectal, transdermal, subcutaneous, intravenous, intramuscular, and 
intranasal. Many of the compounds employed in the methods of this 
invention are effective as both injectable and oral compositions. Such 
compositions are prepared in a manner well known in the pharmaceutical art 
and comprise at least one active compound. See, e.g., REMINGTON'S 
PHARMACEUTICAL SCIENCES, (16th ed. 1980). 
In making the compositions employed in the present invention the active 
ingredient is usually mixed with an excipient, diluted by an excipient or 
enclosed within such a carrier which can be in the form of a capsule, 
sachet, paper or other container. When the excipient serves as a diluent, 
it can be a solid, semi-solid, or liquid material, which acts as a 
vehicle, carrier or medium for the active ingredient. Thus, the 
compositions can be in the form of tablets, pills, powders, lozenges, 
sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, 
aerosols (as a solid or in a liquid medium), ointments containing for 
example up to 10% by weight of the active compound, soft and hard gelatin 
capsules, suppositories, sterile injectable solutions, and sterile 
packaged powders. 
In preparing a formulation, it may be necessary to mill the active compound 
to provide the appropriate particle size prior to combining with the other 
ingredients. If the active compound is substantially insoluble, it 
ordinarily is milled to a particle size of less than 200 mesh. If the 
active compound is substantially water soluble, the particle size is 
normally adjusted by milling to provide a substantially uniform 
distribution in the formulation, e.g. about 40 mesh. 
Some examples of suitable excipients include lactose, dextrose, sucrose, 
sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, 
tragacanth, gelatin, calcium silicate, microcrystalline cellulose, 
polyvinylpyrrolidone, cellulose, water, syrup, and methyl cellulose. The 
formulations can additionally include: lubricating agents such as talc, 
magnesium stearate, and mineral oil; wetting agents; emulsifying and 
suspending agents; preserving agents such as methyl- and 
propylhydroxybenzoates; sweetening agents; and flavoring agents. The 
compositions of the invention can be formulated so as to provide quick, 
sustained or delayed release of the active ingredient after administration 
to the patient by employing procedures known in the art. 
The compositions are preferably formulated in a unit dosage form, each 
dosage containing from about 0.05 to about 100 mg, more usually about 1.0 
to about 30 mg, of the active ingredient. The term "unit dosage form" 
refers to physically discrete units suitable as unitary dosages for human 
subjects and other mammals, each unit containing a predetermined quantity 
of active material calculated to produce the desired therapeutic effect, 
in association with a suitable pharmaceutical excipient. 
The active compounds are generally effective over a wide dosage range. For 
examples, dosages per day normally fall within the range of about 0.01 to 
about 30 mg/kg of body weight. In the treatment of adult humans, the range 
of about 0.1 to about 15 mg/kg/day, in single or divided dose, is 
especially preferred. However, it will be understood that the amount of 
the compound actually administered will be determined by a physician, in 
the light of the relevant circumstances, including the condition to be 
treated, the chosen route of administration, the actual compound or 
compounds administered, the age, weight, and response of the individual 
patient, and the severity of the patient's symptoms, and therefore the 
above dosage ranges are not intended to limit the scope of the invention 
in any way. In some instances dosage levels below the lower limit of the 
aforesaid range may be more than adequate, while in other cases still 
larger doses may be employed without causing any harmful side effect, 
provided that such larger doses are first divided into several smaller 
doses for administration throughout the day. 
Formulation Preparation 1 
Hard gelatin capsules containing the following ingredients are prepared: 
______________________________________ 
Quantity 
Ingredient (mg/capsule) 
______________________________________ 
Active Ingredient(s) 
30.0 
Starch 305.0 
______________________________________ 
The above ingredients are mixed and filled into hard gelatin capsules in 
340 mg quantities. 
Formulation Preparation 2 
A tablet formula is prepared using the ingredients below: 
______________________________________ 
Quantity 
Ingredient (mg/tablet) 
______________________________________ 
Active Ingredient(s) 
25.0 
Cellulose, microcrystalline 200.0 
Colloidal silicon dioxide 10.0 
Stearic acid 5.0 
______________________________________ 
The components are blended and compressed to form tablets, each weighing 
240 mg. 
Formulation Preparation 3 
A dry powder inhaler formulation is prepared containing the following 
components: 
______________________________________ 
Ingredient Weight % 
______________________________________ 
Active Ingredient(s) 
5 
Lactose 95 
______________________________________ 
The active mixture is mixed with the lactose and the mixture is added to a 
dry powder inhaling appliance. 
Formulation Preparation 4 
Tablets, each containing 30 mg of active ingredient, are prepared as 
follows: 
______________________________________ 
Quantity 
Ingredient (mg/tablet) 
______________________________________ 
Active Ingredient(s) 
30.0 mg 
Starch 45.0 mg 
Microcrystalline cellulose 35.0 mg 
Polyvinylpyrrolidone 
(as 10% solution in water) 4.0 mg 
Sodium carboxymethyl starch 4.5 mg 
Magnesium stearate 0.5 mg 
Talc 1.0 mg 
Total 120 mg 
______________________________________ 
The active ingredient, starch and cellulose are passed through a No. 20 
mesh U.S. sieve and mixed thoroughly. The solution of polyvinylpyrrolidone 
is mixed with the resultant powders, which are then passed through a 16 
mesh U.S. sieve. The granules so produced are dried at 50-60.degree. C. 
and passed through a 16 mesh U.S. sieve. The sodium carboxymethyl starch, 
magnesium stearate, and talc, previously passed through a No. 30 mesh U.S. 
sieve, are then added to the granules which, after mixing, are compressed 
on a tablet machine to yield tablets each weighing 120 mg. 
Formulation Preparation 5 
Capsules, each containing 40 mg of medicament are made as follows: 
______________________________________ 
Quantity 
Ingredient (mg/capsule) 
______________________________________ 
Active Ingredient(s) 
40.0 mg 
Starch 109.0 mg 
Magnesium stearate 1.0 mg 
Total 150.0 mg 
______________________________________ 
The active ingredient, cellulose, starch, and magnesium stearate are 
blended, passed through a No. 20 mesh U.S. sieve, and filled into hard 
gelatin capsules in 150 mg quantities. 
Formulation Preparation 6 
Suppositories, each containing 25 mg of active ingredient are made as 
follows: 
______________________________________ 
Ingredient Amount 
______________________________________ 
Active Ingredient(s) 25 mg 
Saturated fatty acid glycerides to 2,000 mg 
______________________________________ 
The active ingredient(s) is passed through a No. 60 mesh U.S. sieve and 
suspended in the saturated fatty acid glycerides previously melted using 
the minimum heat necessary. The mixture is then poured into a suppository 
mold of nominal 2.0 g capacity and allowed to cool. 
Formulation Preparation 7 
Suspensions, each containing 50 mg of medicament per 5.0 ml dose are made 
as follows: 
______________________________________ 
Ingredient Amount 
______________________________________ 
Active Ingredient(s) 50.0 mg 
Xanthan gum 4.0 mg 
Sodium carboxymethyl cellulose (11%) 50.0 mg 
Microcrystalline cellulose (89%) 
Sucrose 1.75 g 
Sodium benzoate 10.0 mg 
Flavor and Color q.v. 
Purified water to 5.0 ml 
______________________________________ 
The medicament, sucrose and xanthan gum are blended, passed through a No. 
10 mesh U.S. sieve, and then mixed with a previously made solution of the 
microcrystalline cellulose and sodium carboxymethyl cellulose in water. 
The sodium benzoate, flavor, and color are diluted with some of the water 
and added with stirring. Sufficient water is then added to produce the 
required volume. 
Formulation Preparation 8 
Capsules, each containing 15 mg of medicament, are made as follows: 
______________________________________ 
Quantity 
Ingredient (mg/capsule) 
______________________________________ 
Active Ingredient(s) 
15.0 mg 
Starch 407.0 mg 
Magnesium stearate 3.0 mg 
Total 425.0 mg 
______________________________________ 
The active ingredient(s), cellulose, starch, and magnesium stearate are 
blended, passed through a No. 20 mesh U.S. sieve, and filled into hard 
gelatin capsules in 425 mg quantities. 
Formulation Preparation 9 
An intravenous formulation may be prepared as follows: 
______________________________________ 
Ingredient Quantity 
______________________________________ 
Active Ingredient(s) 250.0 mg 
Isotonic saline 1000 ml 
______________________________________ 
Formulation Preparation 10 
A topical formulation may be prepared as follows: 
______________________________________ 
Ingredient Quantity 
______________________________________ 
Active Ingredient(s) 1-10 g 
Emulsifying Wax 30 g 
Liquid Paraffin 20 g 
White Soft Paraffin to 100 g 
______________________________________ 
The white soft paraffin is heated until molten. The liquid paraffin and 
emulsifying wax are incorporated and stirred until dissolved. The active 
ingredient is added and stirring is continued until dispersed. The mixture 
is then cooled until solid. 
Formulation Preparation 11 
Sublingual or buccal tablets, each containing 10 mg of active ingredient, 
may be prepared as follows: 
______________________________________ 
Quantity 
Ingredient Per Tablet 
______________________________________ 
Active Ingredient(s) 
10.0 mg 
Glycerol 210.5 mg 
Water 143.0 mg 
Sodium Citrate 4.5 mg 
Polyvinyl Alcohol 26.5 mg 
Polyvinylpyrrolidone 15.5 mg 
Total 410.0 mg 
______________________________________ 
The glycerol, water, sodium citrate, polyvinyl alcohol, and 
polyvinylpyrrolidone are admixed together by continuous stirring and 
maintaining the temperature at about 90.degree. C. When the polymers have 
gone into solution, the solution is cooled to about 50-55.degree. C. and 
the medicament is slowly admixed. The homogenous mixture is poured into 
forms made of an inert material to produce a drug-containing diffusion 
matrix having a thickness of about 2-4 mm. This diffusion matrix is then 
cut to form individual tablets having the appropriate size. 
Another preferred formulation employed in the methods of the present 
invention employs transdermal delivery devices ("patches"). Such 
transdermal patches may be used to provide continuous or discontinuous 
infusion of the compounds of the present invention in controlled amounts. 
The construction and use of transdermal patches for the delivery of 
pharmaceutical agents is well known in the art. See, e.g., U.S. Pat. No. 
5,023,252, issued Jun. 11, 1991, herein incorporated by reference. Such 
patches may be constructed for continuous, pulsatile, or on demand 
delivery of pharmaceutical agents. 
Frequently, it will be desirable or necessary to introduce the 
pharmaceutical composition to the brain, either directly or indirectly. 
Direct techniques usually involve placement of a drug delivery catheter 
into the host's ventricular system to bypass the blood-brain barrier. One 
such implantable delivery system, used for the transport of biological 
factors to specific anatomical regions of the body, is described in U.S. 
Pat. No. 5,011,472, issued Apr. 30, 1991, which is herein incorporated by 
reference. 
Indirect techniques, which are generally preferred, usually involve 
formulating the compositions to provide for drug latentiation by the 
conversion of hydrophilic drugs into lipid-soluble drugs or prodrugs. 
Latentiation is generally achieved through blocking of the hydroxy, 
carbonyl, sulfate, and primary amine groups present on the drug to render 
the drug more lipid soluble and amenable to transportation across the 
blood-brain barrier. Alternatively, the delivery of hydrophilic drugs may 
be enhanced by intra-arterial infusion of hypertonic solutions which can 
transiently open the blood-brain barrier.