U.S. patent application number 12/570859 was filed with the patent office on 2010-04-01 for fluoro substituted cycloalkanoindoles, compositions containing such compounds and methods of treatment.
Invention is credited to Carl Berthelette, Nicolas Lachance, Lianhai Li, Claudio Sturino, Zhaoyin Wang.
Application Number | 20100081696 12/570859 |
Document ID | / |
Family ID | 27613492 |
Filed Date | 2010-04-01 |
United States Patent
Application |
20100081696 |
Kind Code |
A1 |
Berthelette; Carl ; et
al. |
April 1, 2010 |
FLUORO SUBSTITUTED CYCLOALKANOINDOLES, COMPOSITIONS CONTAINING SUCH
COMPOUNDS AND METHODS OF TREATMENT
Abstract
Fluoro substituted cycloalkanoindole derivatives are antagonists
of prostaglandins, and as such are useful for the treatment of
prostaglandin mediated diseases.
Inventors: |
Berthelette; Carl;
(Ste-Dorothee Laval, CA) ; Lachance; Nicolas;
(Pierrefonds, CA) ; Li; Lianhai; (Pierrefonds,
CA) ; Sturino; Claudio; (L'ile-Bizard, CA) ;
Wang; Zhaoyin; (Kirkland, CA) |
Correspondence
Address: |
MERCK AND CO., INC
P O BOX 2000
RAHWAY
NJ
07065-0907
US
|
Family ID: |
27613492 |
Appl. No.: |
12/570859 |
Filed: |
September 30, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11880557 |
Jul 23, 2007 |
7618994 |
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12570859 |
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10502380 |
Jan 28, 2005 |
7317036 |
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PCT/CA03/00084 |
Jan 22, 2003 |
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11880557 |
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60351384 |
Jan 24, 2002 |
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Current U.S.
Class: |
514/356 |
Current CPC
Class: |
A61P 7/02 20180101; A61P
15/00 20180101; A61P 29/00 20180101; A61P 19/10 20180101; A61P
25/04 20180101; A61P 13/08 20180101; A61P 11/06 20180101; A61P
37/08 20180101; A61P 15/06 20180101; A61P 11/00 20180101; A61P
19/08 20180101; A61P 27/02 20180101; A61P 37/06 20180101; C07D
209/80 20130101; A61P 25/20 20180101; A61P 9/10 20180101; A61P
35/04 20180101; A61P 27/16 20180101; A61P 35/00 20180101; A61P 9/08
20180101; A61P 19/02 20180101; A61P 11/02 20180101; A61P 29/02
20180101; A61P 27/06 20180101; A61P 9/04 20180101; A61P 19/00
20180101; A61P 25/06 20180101; A61P 3/10 20180101; A61P 43/00
20180101; A61P 37/02 20180101; C07D 209/88 20130101 |
Class at
Publication: |
514/356 |
International
Class: |
A61K 31/44 20060101
A61K031/44 |
Claims
1. A pharmaceutical composition comprising a compound of formula I:
##STR00026## and pharmaceutically acceptable salts thereof, wherein
n is 0 or 1; m is 1, 2 or 3; R.sub.1 is H, C.sub.1-C.sub.3 alkyl,
halogenated C.sub.1-C.sub.3 alkyl or cyclopropyl; R.sub.2 is
4-chlorophenyl or 2,4,6-trichlorophenyl, and nicotinic acid and a
pharmaceutically acceptable carrier.
2. The composition of claim 1 wherein n is 0.
3. The composition of claim 1 wherein n is 1.
4. The composition of claim 1 wherein m is 1.
5. The composition of claim 1 wherein m is 2.
6. The composition of claim 1 wherein R.sub.1 is H.
7. The compound composition of claim 1 wherein R.sub.1 is
CH.sub.3.
8. The composition of claim 1 wherein R.sub.2 is
4-chloro-phenyl.
9. The composition of claim 1 wherein R.sub.2 is
2,4,6-trichlorophenyl.
10. The composition of claim 1 wherein the compound of Formula I
has the stereoconfiguration shown below: ##STR00027##
11. The composition of claim 10 wherein n is 0.
12. The composition of claim 10 wherein n is 1.
13. The composition of claim 10 wherein in is 1.
14. The composition of claim 10 wherein m is 2.
15. The composition of claim 10 wherein R.sub.1 is H.
16. The composition of claim 10 wherein R.sub.1 is CH.sub.3.
17. The composition of claim 10 wherein R.sub.2 is
4-chloro-phenyl.
18. The composition of claim 10 wherein R.sub.2 is
2,4,6-trichlorophenyl.
19. (canceled)
20. (canceled)
21. (canceled)
22. (canceled)
23. (canceled)
24. (canceled)
25. (canceled)
26. (canceled)
27. (canceled)
28. (canceled)
29. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to compounds and methods for
treating prostaglandin mediated diseases, and certain
pharmaceutical compositions thereof. More particularly, the
compounds of the invention are structurally different from
steroids, antihistamines or adrenergic agonists, and are
antagonists of the nasal and pulmonary congestion effects of D-type
prostaglandins.
[0002] Two review articles describe the characterization and
therapeutic relevance of the prostanoid receptors as well as the
most commonly used selective agonists and antagonists: Eicosanoids:
From Biotechnology to Therapeutic Applications, Folco, Samuelsson,
Maclouf, and Velo eds, Plenum Press, New York, 1996, chap. 14,
137-154 and Journal of Lipid Mediators and Cell Signalling, 1996,
14, 83-87. An article from T. Tsuri et al. published in 1997 in
Journal of Medicinal Chemistry, vol 40, pp. 3504-3507 states that
"PGD2 is considered to be an important mediator in various allergic
diseases such allergic rhinitis, atopic asthma, allergic
conjunctivitis and atopic dermatitis." More recently, an article by
Matsuoka et al. in Science (2000), 287:2013-7, describes PGD2 as
being a key mediator in allergic asthma. In addition, patents such
as U.S. Pat. No. 4,808,608 refer to prostaglandin antagonists as
useful in the treatment of allergic diseases, and explicitly
allergic asthma. PGD2 antagonists are described in, for example,
European Patent Application 837,052 and PCT Application WO98/25919,
as well as WO99/62555.
[0003] U.S. Pat. No. 4,808,608 discloses
tetrahydrocarbazole-1-alkanoic acid derivatives as prostaglandin
antagonists.
[0004] PCT Application WO0179169 discloses PGD2 antagonists having
the formula:
##STR00001##
[0005] European Patent Application 468,785 discloses the compound
4-[(4-chlorophenyl)methyl]-1,2,3,4-tetrahydro-7-(2-quinolinylmethoxy)-cyc-
lopent[b]indole-3-acetic acid, which is a species of a genus said
to be leukotriene biosynthesis inhibitors.
[0006] U.S. Pat. No. 3,535,326 discloses antiphlogistic compounds
of the formula:
##STR00002##
SUMMARY OF THE INVENTION
[0007] The present invention provides novel compounds which are
prostaglandin receptor antagonists; more particularly, they are
prostaglandin D2 receptor (DP receptor) antagonists. Compounds of
the present invention are useful for the treatment of various
prostaglandin-mediated diseases and disorders; accordingly the
present invention provides a method for the treatment of
prostaglandin-mediated diseases using the novel compounds described
herein, as well as pharmaceutical compositions containing them.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The present invention relates to compounds of formula I:
##STR00003##
and pharmaceutically acceptable salts thereof, wherein n is 0 or 1;
m is 1, 2 or 3; R.sub.1 is H, C.sub.1-C.sub.3 alkyl, halogenated
C.sub.1-C.sub.3 alkyl or cyclopropyl; R.sub.2 is 4-chlorophenyl or
2,4,6-trichlorophenyl.
[0009] In one embodiment of formula I are compounds wherein n is
0.
[0010] In another embodiment of formula I are compounds wherein n
is 1.
[0011] In another embodiment of formula I are compounds wherein m
is 1.
[0012] In another embodiment of formula I are compounds wherein m
is 2.
[0013] In another embodiment of formula I are compounds wherein
R.sub.1 is H.
In another embodiment of formula I are compounds wherein R.sub.1 is
CH.sub.3.
[0014] In another embodiment of formula I are compounds wherein
R.sub.2 is 4-chlorophenyl.
[0015] In another embodiment of formula I are compounds wherein
R.sub.2 is 2,4,6-trichlorophenyl.
[0016] In another embodiment of formula I are compounds having the
stereoconfiguration shown below (i.e. the chiral center has the R
configuration):
##STR00004##
[0017] In another aspect of the present invention there is provided
pharmaceutical compositions comprising a compound of formula I, and
a pharmaceutically acceptable carrier.
[0018] In one embodiment, the pharmaceutical compositions further
comprises a second active ingredient selected from an
antihistamine, a leukotriene antagonist, leukotriene biosynthesis
inhibitor, prostaglandin receptor antagonists or biosynthesis
inhibitors, corticosteroids, cytokine modulators, anti-IgE,
anti-cholinergics or NSAIDS.
[0019] In another aspect of the present invention there is provided
a method for the treatment or prevention of prostaglandin D2
mediated diseases which comprises administering to a patient in
need of treatment a therapeutically effective amount of a compound
of formula I.
[0020] In one embodiment of the invention is a method of treating
or preventing a prostaglandin D2 mediated disease comprising
administering to a mammalian patient in need of such treatment a
compound of formula I in an amount which is effective for treating
or preventing a prostaglandin D2 mediated disease, wherein the
prostaglandin mediated disease is nasal congestion, rhinitis
including seasonal allergic rhinitis and perennial allergic
rhinitis, and asthma including allergic asthma.
[0021] In another embodiment of the present invention is a method
for the treatment of nasal congestion in a patient in need of such
treatment which comprises administering to said patient a
therapeutically effective amount of a compound of formula I.
[0022] In yet another embodiment of the present invention is a
method for the treatment of asthma, including allergic asthma, in a
patient in need of such treatment which comprises administering to
said patient a therapeutically effective amount of a compound of
formula I.
[0023] In yet another embodiment of the present invention is a
method for the treatment of allergic rhinitis (seasonal and
perennial) in a patient in need of such treatment which comprises
administering to said patient a therapeutically effective amount of
a compound of formula I.
[0024] The numbering of the core tricyclic ring system when m is 1
is as shown below:
##STR00005##
[0025] The numbering of the core tricyclic ring system when m is 2
is as shown below:
##STR00006##
Optical Isomers--Diastereomers--Tautomers
[0026] Compounds of formula I contain one or more asymmetric
centers and can thus occur as racemates and racemic mixtures,
single enantiomers, diastereomeric mixtures and individual
diastereomers. The present invention is meant to comprehend all
such isomeric forms of the compounds of formula I.
[0027] Some of the compounds described herein may exist with
different points of attachment of hydrogen, referred to as
tautomers. Such an example may be a ketone and its enol form known
as keto-enol tautomers. The individual tautomers as well as mixture
thereof are encompassed with compounds of formula I.
[0028] Compounds of formula I may be separated into
diastereoisomeric pairs of enantiomers by, for example, fractional
crystallization from a suitable solvent, for example methanol or
ethyl acetate or a mixture thereof. The pair of enantiomers thus
obtained may be separated into individual stereoisomers by
conventional means, for example by the use of an optically active
acid or base as a resolving agent, or by chiral separation
techniques such as separation by HPLC using a chiral column.
[0029] Alternatively, any enantiomer of a compound of the general
formula I or Ia may be obtained by stereospecific synthesis using
optically pure starting materials or reagents of known
configuration.
Salts
[0030] The term "pharmaceutically acceptable salts" refers to salts
prepared from pharmaceutically acceptable non-toxic bases including
inorganic bases and organic bases. Salts derived from inorganic
bases include aluminum, ammonium, calcium, copper, ferric, ferrous,
lithium, magnesium, manganic salts, manganous, potassium, sodium,
zinc, and the like. Particularly preferred are the ammonium,
calcium, magnesium, potassium, and sodium salts. Salts derived from
pharmaceutically acceptable organic non-toxic bases include salts
of primary, secondary, and tertiary amines, substituted amines
including naturally occurring substituted amines, cyclic amines,
and basic ion exchange resins, such as arginine, betaine, caffeine,
choline, N,N'-dibenzylethylenediamine, diethylamine,
2-diethyl-aminoethanol, 2-dimethylaminoethanol, ethanolamine,
ethylenediamine, N-ethyl-morpholine, N-ethylpiperidine, glucamine,
glucosamine, histidine, hydrabamine, isopropylamine, lysine,
methylglucamine, morpholine, piperazine, piperidine, polyamine
resins, procaine, purines, theobromine, triethylamine,
trimethylamine, tripropylamine, tromethamine, and the like.
[0031] When the compound of the present invention is basic, salts
may be prepared from pharmaceutically acceptable non-toxic acids,
including inorganic and organic acids. Such acids include acetic,
benzenesulfonic, benzoic, camphorsulfonic, citric, ethanesulfonic,
fumaric, gluconic, glutamic, hydrobromic, hydrochloric, isethionic,
lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric,
pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric,
p-toluenesulfonic acid, and the like. Particularly preferred are
citric, hydrobromic, hydrochloric, maleic, phosphoric, sulfuric,
and tartaric acids.
[0032] It will be understood that, unless otherwise specified,
references to the compound of formula I are meant to also include
the pharmaceutically acceptable salts.
Utilities
[0033] Compounds of formula I are antagonists of prostaglandin D2.
The ability of compounds of formula Ito interact with prostaglandin
D2 receptor makes them useful for preventing or reversing
undesirable symptoms caused by prostaglandins in a mammalian,
especially human subject. The antagonism of the actions of
prostaglandin D2 indicates that the compounds and pharmaceutical
compositions thereof are useful to treat, prevent, or ameliorate in
mammals and especially in humans: respiratory conditions, allergic
conditions, pain, inflammatory conditions, mucus secretion
disorders, bone disorders, sleep disorders, fertility disorders,
blood coagulation disorders, trouble of the vision as well as
immune and autoimmune diseases. In addition, such a compound may
inhibit cellular neoplastic transformations and metastic tumor
growth and hence can be used in the treatment of cancer. Compounds
of formula I may also be of use in the treatment and/or prevention
prostaglandin D2 mediated proliferation disorders such as may occur
in diabetic retinopathy and tumor angiogenesis. Compounds of
formula I may also inhibit prostanoid-induced smooth muscle
contraction by antagonizing contractile prostanoids or mimicking
relaxing prostanoids and hence may be use in the treatment of
dysmenorrhea, premature labor and eosinophil related disorders.
[0034] Accordingly, another aspect of the invention provides a
method of treating or preventing a prostaglandin D2 mediated
disease comprising administering to a mammalian patient in need of
such treatment a compound of formula I in an amount which is
effective for treating or preventing said prostaglandin D2 mediated
disease. Prostaglandin D2 mediated diseases include, but are not
limited to, allergic rhinitis, nasal congestion, rhinorrhea,
perennial rhinitis, nasal inflammation, asthma including allergic
asthma, chronic obstructive pulmonary diseases and other forms of
lung inflammation; pulmonary hypotension; sleep disorders and
sleep-wake cycle disorders; prostanoid-induced smooth muscle
contraction associated with dysmenorrhea and premature labor;
eosinophil related disorders; thrombosis; glaucoma and vision
disorders; occlusive vascular diseases, such as for example
atherosclerosis; congestive heart failure; diseases or conditions
requiring a treatment of anti-coagulation such as post-injury or
post surgery treatment; rheumatoid arthritis and other inflammatory
diseases; gangrene; Raynaud's disease; mucus secretion disorders
including cytoprotection; pain and migraine; diseases requiring
control of bone formation and resorption such as for example
osteoporosis; shock; thermal regulation including fever; rejection
in organ transplant and by-pass surgery, and immune disorders or
conditions in which immunoregulation is desirable. More
particularly the disease to be treated is one mediated by
prostaglandin D2 such as nasal congestion, allergic rhinitis,
pulmonary congestion, and asthma including allergic asthma.
Dose Ranges
[0035] The magnitude of prophylactic or therapeutic dose of a
compound of formula I will, of course, vary with the nature and the
severity of the condition to be treated and with the particular
compound of formula I and its route of administration. It will also
vary according to a variety of factors including the age, weight,
general health, sex, diet, time of administration, rate of
excretion, drug combination and response of the individual patient.
In general, the daily dose from about 0.001 mg to about 100 mg per
kg body weight of a mammal, preferably 0.01 mg to about 10 mg per
kg. On the other hand, it may be necessary to use dosages outside
these limits in some cases.
[0036] The amount of active ingredient that may be combined with
the carrier materials to produce a single dosage form will vary
depending upon the host treated and the particular mode of
administration. For example, a formulation intended for the oral
administration of humans may contain from 0.05 mg to 5 g of active
agent compounded with an appropriate and convenient amount of
carrier material which may vary from about 5 to about 99.95 percent
of the total composition. Dosage unit forms will generally contain
between from about 0.1 mg to about 0.4 g of an active ingredient,
typically 0.5 mg, 1 mg, 2 mg, 5 mg, 10 mg, 25 mg, 50 mg, 100 mg,
200 mg, or 400 mg.
Pharmaceutical Compositions
[0037] Another aspect of the present invention provides
pharmaceutical compositions comprising a compound of formula I with
a pharmaceutically acceptable carrier. The term "composition", as
in pharmaceutical composition, is intended to encompass a product
comprising the active ingredient(s), and the inert ingredient(s)
(pharmaceutically acceptable excipients) that make up the carrier,
as well as any product which results, directly or indirectly, from
combination, complexation or aggregation of any two or more of the
ingredients, or from dissociation of one or more of the
ingredients, or from other types of reactions or interactions of
one or more of the ingredients. Accordingly, the pharmaceutical
compositions of the present invention encompass any composition
made by admixing a compound of Formula I, additional active
ingredient(s), and pharmaceutically acceptable excipients.
[0038] For the treatment of any of the prostanoid mediated diseases
compounds of formula I may be administered orally, by inhalation
spray, topically, parenterally or rectally in dosage unit
formulations containing conventional non-toxic pharmaceutically
acceptable carriers, adjuvants and vehicles. The term parenteral as
used herein includes subcutaneous injections, intravenous,
intramuscular, intrasternal injection or infusion techniques. In
addition to the treatment of warm-blooded animals such as mice,
rats, horses, cattle, sheep, dogs, cats, etc., the compound of the
invention is effective in the treatment of humans.
[0039] The pharmaceutical compositions containing the active
ingredient may be in a form suitable for oral use, for example, as
tablets, troches, lozenges, aqueous or oily suspensions,
dispersible powders or granules, emulsions, hard or soft capsules,
or syrups or elixirs. Compositions intended for oral use may be
prepared according to any method known to the art for the
manufacture of pharmaceutical compositions and such compositions
may contain one or more agents selected from the group consisting
of sweetening agents, flavouring agents, colouring agents and
preserving agents in order to provide pharmaceutically elegant and
palatable preparations. Tablets contain the active ingredient in
admixture with non-toxic pharmaceutically acceptable excipients
which are suitable for the manufacture of tablets. These excipients
may be for example, inert diluents, such as calcium carbonate,
sodium carbonate, lactose, calcium phosphate or sodium phosphate;
granulating and disintegrating agents, for example, corn starch, or
alginic acid; binding agents, for example starch, gelatin or
acacia, and lubricating agents, for example, magnesium stearate,
stearic acid or talc. The tablets may be uncoated or they may be
coated by known techniques to delay disintegration and absorption
in the gastrointestinal tract and thereby provide a sustained
action over a longer period. For example, a time delay material
such as glyceryl monostearate or glyceryl distearate may be
employed. They may also be coated by the technique described in the
U.S. Pat. Nos. 4,256,108; 4,166,452; and 4,265,874 to form osmotic
therapeutic tablets for control release.
[0040] Formulations for oral use may also be presented as hard
gelatin capsules wherein the active ingredient is mixed with an
inert solid diluent, for example, calcium carbonate, calcium
phosphate or kaolin, or as soft gelatin capsules wherein the active
ingredients is mixed with water-miscible solvents such as propylene
glycol, PEGs and ethanol, or an oil medium, for example peanut oil,
liquid paraffin, or olive oil.
[0041] Aqueous suspensions contain the active material in admixture
with excipients suitable for the manufacture of aqueous
suspensions. Such excipients are suspending agents, for example
sodium carboxymethylcellulose, methylcellulose, hydroxypropyl
methylcellulose, sodium alginate, polyvinylpyrrolidone, gum
tragacanth and gum acacia; dispersing or wetting agents may be a
naturally-occurring phosphatide, for example lecithin, or
condensation products of an alkylene oxide with fatty acids, for
example polyoxyethylene stearate, or condensation products of
ethylene oxide with long chain aliphatic alcohols, for example
heptadecaethyleneoxy-cetanol, or condensation products of ethylene
oxide with partial esters derived from fatty acids and a hexitol
such as polyoxyethylene sorbitol monooleate, or condensation
products of ethylene oxide with partial esters derived from fatty
acids and hexitol anhydrides, for example polyethylene sorbitan
monooleate. The aqueous suspensions may also contain one or more
preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate,
one or more colouring agents, one or more flavouring agents, and
one or more sweetening agents, such as sucrose, saccharin or
aspartame.
[0042] Oily suspensions may be formulated by suspending the active
ingredient in a vegetable oil, for example arachis oil, olive oil,
sesame oil or coconut oil, or in mineral oil such as liquid
paraffin. The oily suspensions may contain a thickening agent, for
example beeswax, hard paraffin or cetyl alcohol. Sweetening agents
such as those set forth above, and flavouring agents may be added
to provide a palatable oral preparation. These compositions may be
preserved by the addition of an anti-oxidant such as ascorbic
acid.
[0043] Dispersible powders and granules suitable for preparation of
an aqueous suspension by the addition of water provide the active
ingredient in admixture with a dispersing or wetting agent,
suspending agent and one or more preservatives. Suitable dispersing
or wetting agents and suspending agents are exemplified by those
already mentioned above. Additional excipients, for example
sweetening, flavouring and colouring agents, may also be
present.
[0044] The pharmaceutical compositions of the invention may also be
in the form of an oil-in-water emulsion. The oily phase may be a
vegetable oil, for example olive oil or arachis oil, or a mineral
oil, for example liquid paraffin or mixtures of these. Suitable
emulsifying agents may be naturally-occurring phosphatides, for
example soy bean, lecithin, and esters or partial esters derived
from fatty acids and hexitol anhydrides, for example sorbitan
monooleate, and condensation products of the said partial esters
with ethylene oxide, for example polyoxyethylene sorbitan
monooleate. The emulsions may also contain sweetening and
flavouring agents.
[0045] Syrups and elixirs may be formulated with sweetening agents,
for example glycerol, propylene glycol, sorbitol or sucrose. Such
formulations may also contain a demulcent, a preservative and
flavouring and colouring agents. The pharmaceutical compositions
may be in the form of a sterile injectable aqueous or oleagenous
suspension. This suspension may be formulated according to the
known art using those suitable dispersing or wetting agents and
suspending agents which have been mentioned above. The sterile
injectable preparation may also be a sterile injectable solution or
suspension in a non-toxic parenterally-acceptable diluent or
solvent, for example as a solution in 1,3-butane diol. Among the
acceptable vehicles and solvents that may be employed are water,
Ringer's solution and isotonic sodium chloride solution. Cosolvents
such as ethanol, propylene glycol or polyethylene glycols may also
be used. In addition, sterile, fixed oils are conventionally
employed as a solvent or suspending medium. For this purpose any
bland fixed oil may be employed including synthetic mono- or
diglycerides. In addition, fatty acids such as oleic acid find use
in the preparation of injectables.
[0046] Compounds of formula I may also be administered in the form
of suppositories for rectal administration of the drug. These
compositions can be prepared by mixing the drug with a suitable
non-irritating excipient which is solid at ambient temperatures but
liquid at the rectal temperature and will therefore melt in the
rectum to release the drug. Such materials are cocoa butter and
polyethylene glycols.
[0047] For topical use, creams, ointments, gels, solutions or
suspensions, etc., containing the compound of formula I are
employed. (For purposes of this application, topical application
shall include mouth washes and gargles.) Topical formulations may
generally be comprised of a pharmaceutical carrier, cosolvent,
emulsifier, penetration enhancer, preservative system, and
emollient.
Combinations with Other Drugs
[0048] For the treatment and prevention of prostaglandin mediated
diseases, compound of formula I may be co-administered with other
therapeutic agents. Thus in another aspect the present invention
provides pharmaceutical compositions for treating prostaglandin D2
mediated diseases comprising a therapeutically effective amount of
a compound of formula I and one or more other therapeutic agents.
Suitable therapeutic agents for combination therapy with a compound
of formula I include: (1) a prostaglandin receptor antagonist; (2)
a corticosteroid such as triamcinolone acetonide; (3) a
.beta.-agonist such as salmeterol, formoterol, terbutaline,
metaproterenol, albuterol and the like; (4) a leukotriene modifier,
such as a leukotriene antagonist or a lipooxygenase inhibitor such
as montelukast, zafirlukast, pranlukast, or zileuton; (5) an
antihistamine (histamine H1 antagonist) such as bromopheniramine,
chlorpheniramine, dexchlorpheniramine, triprolidine, clemastine,
diphenhydramine, diphenylpyraline, tripelennamine, hydroxyzine,
methdilazine, promethazine, trimeprazine, azatadine,
cyproheptadine, antazoline, pheniramine, pyrilamine, astemizole,
norastemizole, terfenadine, loratadine, cetirizine, levocetirizine,
fexofenadine, desloratadine, and the like; (6) a decongestant
including phenylephrine, phenylpropanolamine, pseudophedrine,
oxymetazoline, ephinephrine, naphazoline, xylometazoline,
propylhexedrine, or levo-desoxyephedrine; (7) an antiitussive
including codeine, hydrocodone, caramiphen, carbetapentane, or
dextramethorphan; (8) another prostaglandin ligand including
prostaglandin F agonist such as latanoprost; misoprostol,
enprostil, rioprostil, ornoprostol or rosaprostol; (9) a diuretic;
(10) non-steroidal antiinflammatory agents (NSAIDs) such as
propionic acid derivatives (alminoprofen, benoxaprofen, bucloxic
acid, carprofen, fenbufen, fenoprofen, fluprofen, flurbiprofen,
ibuprofen, indoprofen, ketoprofen, miroprofen, naproxen, oxaprozin,
pirprofen, pranoprofen, suprofen, tiaprofenic acid, and
tioxaprofen), acetic acid derivatives (indomethacin, acemetacin,
alclofenac, clidanac, diclofenac, fenclofenac, fenclozic acid,
fentiazac, furofenac, ibufenac, isoxepac, oxpinac, sulindac,
tiopinac, tolmetin, zidometacin, and zomepirac), fenamic acid
derivatives (flufenamic acid, meclofenamic acid, mefenamic acid,
niflumic acid and tolfenamic acid), biphenylcarboxylic acid
derivatives (diflunisal and flufenisal), oxicams (isoxicam,
piroxicam, sudoxicam and tenoxican), salicylates (acetyl salicylic
acid, sulfasalazine) and the pyrazolones (apazone, bezpiperylon,
feprazone, mofebutazone, oxyphenbutazone, phenylbutazone); (11)
cyclooxygenase-2 (COX-2) inhibitors such as celecoxib and
rofecoxib, etoricoxib and valdecoxib; (12) inhibitors of
phosphodiesterase type IV (PDE-IV) e.g. Ariflo, roflumilast; (13)
antagonists of the chemokine receptors, especially CCR-1, CCR-2,
and CCR-3; (14) cholesterol lowering agents such as HMG-CoA
reductase inhibitors (lovastatin, simvastatin and pravastatin,
fluvastatin, atorvastatin, and other statins), sequestrants
(cholestyramine and colestipol), nicotinic acid, fenofibric acid
derivatives (gemfibrozil, clofibrat, fenofibrate and benzafibrate),
and probucol; (15) anti-diabetic agents such as insulin,
sulfonylureas, biguanides (metformin), .alpha.-glucosidase
inhibitors (acarbose) and glitazones (troglitazone, pioglitazone,
englitazone, rosiglitazone and the like); (16) preparations of
interferon beta (interferon beta-1a, interferon beta-1b); (17)
anticholinergic agents such as muscarinic antagonists (ipratropium
bromide and tiotropium bromide), as well as selective muscarinic M3
antagonists; (18) steroids such as beclomethasone,
methylprednisolone, betamethasone, prednisone, dexamethasone, and
hydrocortisone; (19) triptans commonly used for the treatment of
migraine such as sumitriptan and rizatriptan; (20) alendronate and
other treatments for osteoporosis; (21) other compounds such as
5-aminosalicylic acid and prodrugs thereof, antimetabolites such as
azathioprine and 6-mercaptopurine, cytotoxic cancer
chemotherapeutic agents, bradykinin (BK2 or BK1) antagonists, TP
receptor antagonists such as seratrodast, neurokinin antagonists
(NK1/NK2), VLA-4 antagonists such as those described in U.S. Pat.
No. 5,510,332, WO97/03094, WO97/02289, WO96/40781, WO96/22966,
WO96/20216, WO96/01644, WO96/06108, WO95/15973 and WO96/31206.
[0049] In addition, the invention encompasses a method of treating
prostaglandin D2 mediated diseases comprising: administering to a
patient in need of such treatment a therapeutically effective
amount of the compound of formula I, co-administered with one or
more of such ingredients as listed immediately above. The amounts
of active ingredients may be those commonly used for each active
ingredient when it is administered alone, or in some instances the
combination of active ingredients may result in lower dosage for
one or more of the active ingredients.
Abbreviations Used
[0050] Ac acetyl
[0051] AcOH acetic acid
[0052] DDQ 2,3-dichloro-5,6-dicyano-1,4-benzoquinone
[0053] DMF dimethylformamide
[0054] eq. equivalents)
[0055] Et ethyl
[0056] EtOAc ethyl acetate
[0057] EtOH ethanol
[0058] HPLC high pressure liquid chromatography
[0059] IPA isopropyl alcohol
[0060] IPAc isopropyl acetate
[0061] Me methyl
[0062] MeOH methanol
[0063] MHz megahertz
[0064] MTBE methyl t-butyl ether
[0065] NMP N-methyl-2-pyrrolidinone
[0066] NMR nuclear magnetic resonance
[0067] THF tetrahydrofuran
[0068] TLC thin-layer chromatography
Methods of Synthesis
[0069] Compounds of Formula I of the present invention can be
prepared according to the synthetic routes outlined in Schemes 1 to
5 and by following the methods described herein.
[0070] Intermediate compounds of Formula IV may be prepared by the
method presented in Scheme 1 from an appropriately substituted
phenyl hydrazine II. Reaction of II with an appropriate
cycloalkanone III (where R is ester group such as an alkyl group)
under Fisher Indole or similar conditions gives IV.
##STR00007##
[0071] Compounds of Formula IV may alternatively be prepared by the
method presented in Scheme 2 from an appropriately substituted
aniline V. Condensation of V with an appropriate cycloalkanone III
followed by the cyclization under Heck or similar metal catalysis
conditions leads to indole IV.
##STR00008##
[0072] Compounds of Formula III may be prepared by the method
presented in Scheme 3 from an appropriately substituted silyl enol
ether VI or an appropriately substituted enamine VII. Addition of
an appropriate electrophile such as Y--CH.sub.2CO.sub.2R (wherein Y
represents a halogen or a leaving group) in the presence of a base
such as an alkyl lithium or a Lewis acid such as silver
trifluoroacetate with the silyl enol ether VI gives the
cycloalkanone III. The compound of formula III may alternatively be
prepared from the addition of Y--CH.sub.2CO.sub.2R on an
appropriately substituted enamine VII under Stork Enamine or
similar conditions.
##STR00009##
[0073] Intermediate compounds of Formula VIII may be prepared by
the method presented in Scheme 4 from an appropriately substituted
indole IV. Bromination of IV may be accomplished with bromine or a
brominating agent such as pyridium tribromide, under basic
condition in a polar solvent, for example, by carrying out the
reaction in pyridine or in a solvent such as dichloromethane in the
presence of pyridine followed by the mono reduction of a dibromo
intermediate under acid and reducing metal conditions to generate
the bromoindole VIII.
##STR00010##
[0074] Compounds of Formula I may be prepared by the method
presented in Scheme 5 from an appropriately substituted bromoindole
VIII. Alkylation of VIII with the appropriate electrophile such as
(R.sub.1)(R.sub.2)CH--Y in the presence of a base and in a suitable
solvent such as DMF gives N-alkylated indole IX. Coupling of IX
with a methanesulfinate such as sodium methanesulfinate in the
presence of Cu(I) salts leads to compounds of formula I, following
ester hydrolysis. The bromoindole acid (IX, R.dbd.H) may
alternatively first react with a suitable metallation agent, such
as n-BuLi, followed by trapping with an electrophile such as methyl
disulfide to give the corresponding methyl sulfide, which upon
oxidation with for example hydrogen peroxide/sodium tungstate
provides compound IA. The steps of alkylation of the bromoindole
VIII followed by sulfonylation may also be reversed; thus
sulfonylation of the bromoindole VIII provides the compound X,
which is alkylated using similar conditions as described before or
by using Mitsunobu reaction conditions to provide compound of
formula IA following ester hydrolysis.
##STR00011##
[0075] Compound IB may be prepared from protected IA, for example
an ester of IA, by oxidation using a suitable oxidant followed by
hydrolysis, as illustrated in Scheme 6.
##STR00012##
Alternatively, IB can be prepared, as illustrated in Scheme 7, by
oxidizing IX with a suitable oxidizing agent, such as DDQ, followed
by methylsulfonylation as described in Scheme 5 followed by
hydrolysis.
##STR00013##
Assays for Determining Biological Activity
[0076] Compounds of formula I can be tested using the following
assays to determine their prostanoid antagonist or agonist activity
in vitro and in vivo and their selectivity. The prostaglandin
receptor activities demonstrated are DP, EP.sub.1, EP.sub.2,
EP.sub.3, EP.sub.4, FP, IP and TP.
Stable Expression of Prostanoid Receptors in the Human Embryonic
Kidney (HEK) 293(ebna) Cell Line
[0077] Prostanoid receptor cDNAs corresponding to full length
coding sequences are subcloned into the appropriate sites of
mammalian expression vectors and transfected into HEK 293(ebna)
cells. HEK 293(ebna) cells expressing the individual cDNAs are
grown under selection and individual colonies are isolated after
2-3 weeks of growth using the cloning ring method and subsequently
expanded into clonal cell lines.
Prostanoid Receptor Binding Assays
[0078] HEK 293(ebna) cells are maintained in culture, harvested and
membranes are prepared by differential centrifugation, following
lysis of the cells in the presence of protease inhibitors, for use
in receptor binding assays. Prostanoid receptor binding assays are
performed in 10 mM MES/KOH (pH 6.0) (EPs, FP and TP) or 10 mM
HEPES/KOH (pH 7.4) (DP and IP), containing 1 mM EDTA, 10 mM
divalent cation and the appropriate radioligand. The reaction is
initiated by addition of membrane protein. Ligands are added in
dimethylsulfoxide which is kept constant at 1% (v/v) in all
incubations. Non-specific binding is determined in the presence of
1 .mu.M of the corresponding non-radioactive prostanoid.
Incubations are conducted for 60 min at room temperature or
30.degree. C. and terminated by rapid filtration. Specific binding
is calculated by subtracting non specific binding from total
binding. The residual specific binding at each ligand concentration
is calculated and expressed as a function of ligand concentration
in order to construct sigmoidal concentration-response curves for
determination of ligand affinity.
Prostanoid Receptor Agonist and Antagonist Assays
[0079] Whole cell second messenger assays measuring stimulation
(EP2, EP4, DP and IP in HEK 293(ebna) cells) or inhibition (EP3 in
human erythroleukemia (HEL) cells) of intracellular cAMP
accumulation or mobilization of intracellular calcium (EP.sub.1, FP
and TP in HEK 293(ebna) cells stably transfected with apo-aequorin)
are performed to determine whether receptor ligands are agonists or
antagonists. For cAMP assays, cells are harvested and resuspended
in HBSS containing 25 mM HEPES, pH 7.4. Incubations contain 100
.mu.M RO-20174 (phosphodiesterase type IV inhibitor, available from
Biomol) and, in the case of the EP.sub.3 inhibition assay only, 15
.mu.M forskolin to stimulate cAMP production. Samples are incubated
at 37.degree. C. for 10 min, the reaction is terminated and cAMP
levels are then measured. For calcium mobilization assays, cells
are charged with the co-factors reduced glutathione and
coelenterazine, harvested and resuspended in Ham's F12 medium.
Calcium mobilization is measured by monitoring luminescence
provoked by calcium binding to the intracellular photoprotein
aequorin. Ligands are added in dimethylsulfoxide which is kept
constant at 1% (v/v) in all incubations. For agonists, second
messenger responses are expressed as a function of ligand
concentration and both EC.sub.50 values and the maximum response as
compared to a prostanoid standard are calculated. For antagonists,
the ability of a ligand to inhibit an agonist response is
determined by Schild analysis and both KB and slope values are
calculated.
Prevention of PGD2 or Allergen Induced Nasal Congestion in Allergic
Sheep
[0080] Animal preparation: Healthy adult sheeps (18-50 kg) are
used. These animals are selected on the basis of a natural positive
skin reaction to an intradermal injection of Ascaris suum
extract.
[0081] Measurements of nasal congestion: The experiment is
performed on conscious animals. They are restained in a cart in a
prone position with their heads immobilized. Nasal airway
resistance (NAR) is measured using a modified mask rhinometry
technique. A topical anaesthesia (2% lidocaine) is applied to the
nasal passage for the insertion of a nasotracheal tube. The maximal
end of the tube is connected to a pneumotachograph and a flow and
pressure signal is recorded on an oscilloscope linked to a computer
for on-line calculation of NAR. Nasal provocation is performed by
the administration of an aerosolized solution (10 puffs/nostril).
Changes in the NAR congestion are recorded prior to and for 60-120
minutes post-challenge.
Prevention of PGD2 and Allergen Induced Nasal Obstruction in
Cynomolgus Monkey
[0082] Animal preparation: Healthy adult male cynomologus monkeys
(4-10 kg) are used. These animals are selected on the basis of a
natural positive skin reaction to an intradermal injection of
Ascaris suum extract. Before each experiment, the monkey selected
for a study is fasted overnight with water provided at libitum. The
next morning, the animal is sedated with ketamine (10-15 mg/kg
i.m.) before being removed from its home cage. It is placed on a
heated table (36.degree. C.) and injected with a bolus dose (5-12
mg/kg i.v.) of propofol. The animal is intubated with a cuffed
endotracheal tube (4-6 mm I.D.) and anaesthesia is maintained via a
continuous intravenous infusion of propofol (25-30 mg/kg/h). Vital
signs (heart rate, blood pressure, respiratory rate, body
temperature) are monitored throughout the experiment.
[0083] Measurements of nasal congestion: A measurement of the
animal respiratory resistance is taken via a pneumotachograph
connected to the endotracheal tube to ensure that it is normal. An
Ecovision accoustic rhinometer is used to evaluate nasal
congestion. This technique gives a non-invasive 2D echogram of the
inside of the nose. The nasal volume and the minimal
cross-sectional area along the length of the nasal cavity are
computed within 10 seconds by a laptop computer equipped with a
custom software (Hood Laboratories, Mass, U.S.A.). Nasal challenge
is delivered directly to the animal's nasal cavity (50 .mu.L
volume). The changes in nasal congestion are recorded prior to and
for 60-120 minutes post-challenge. If nasal congestion occurs, it
will translate into a reduction in the nasal volume.
Pulmonary Mechanics in Trained Conscious Squirrel Monkeys
[0084] The test procedure involves placing trained squirrel monkeys
in chairs in aerosol exposure chambers. For control purposes,
pulmonary mechanics measurements of respiratory parameters are
recorded for a period of about 30 minutes to establish each
monkey's normal control values for that day. For oral
administration, compounds are dissolved or suspended in a 1%
methocel solution (methylcellulose, 65HG, 400 cps) and given in a
volume of 1 mL/kg body weight. For aerosol administration of
compounds, a DeVilbiss ultrasonic nebulizer is utilized.
Pretreatment periods vary from 5 minutes to 4 hours before the
monkeys are challenged with aerosol doses of either PGD2 or Ascaris
suum antigen; 1:25 dilution.
[0085] Following challenge, each minute of data is calculated by
computer as a percent change from control values for each
respiratory parameter including airway resistance (R.sub.L) and
dynamic compliance (C.sub.dyn). The results for each test compound
are subsequently obtained for a minimum period of 60 minutes post
challenge which are then compared to previously obtained historical
baseline control values for that monkey. In addition, the overall
values for 60 minutes post-challenge for each monkey (historical
baseline values and test values) are averaged separately and are
used to calculate the overall percent inhibition of mediator or
Ascaris antigen response by the test compound. For statistical
analysis, paired t-test is used. (References: McFarlane, C. S. et
al., Prostaglandins, 28, 173-182 (1984) and McFarlane, C. S. et
al., Agents Actions, 22, 63-68 (1987).)
Prevention of Induced Bronchoconstriction in Allergic Sheep
[0086] Animal Preparation: Adult sheep with a mean weight of 35 kg
(range, 18 to 50 kg) are used. All animals used meet two criteria:
a) they have a natural cutaneous reaction to 1:1,000 or 1:10,000
dilutions of Ascaris suum extract (Greer Diagnostics, Lenois,
N.C.); and b) they have previously responded to inhalation
challenge with Ascaris suum with both an acute bronchoconstriction
and a late bronchial obstruction (W. M. Abraham et al., Am. Rev.
Resp. Dis., 128, 839-44 (1983)).
[0087] Measurement of Airway Mechanics: The unsedated sheep are
restrained in a cart in the prone position with their heads
immobilized. After topical anesthesia of the nasal passages with 2%
lidocaine solution, a balloon catheter is advanced through one
nostril into the lower esophagus. The animals are then intubated
with a cuffed endotracheal tube through the other nostril using a
flexible fiberoptic bronchoscope as a guide. Pleural pressure is
estimated with the esophageal balloon catheter (filled with one mL
of air), which is positioned such that inspiration produces a
negative pressure deflection with clearly discernible cardiogenic
oscillations. Lateral pressure in the trachea is measured with a
sidehole catheter (inner dimension, 2.5 mm) advanced through and
positioned distal to the tip of the nasotracheal tube.
Transpulmonary pressure, the difference between tracheal pressure
and pleural pressure, is measured with a differential pressure
transducer (DP45; Validyne Corp., Northridge, Calif.). For the
measurement of pulmonary resistance (R.sub.L), the maximal end of
the nasotrachel tube is connected to a pneumotachograph (Fleisch,
Dyna Sciences, Blue Bell, Pa.). The signals of flow and
transpulmonary pressure are recorded on an oscilloscope (Model
DR-12; Electronics for Medicine, White Plains, N.Y.) which is
linked to a PDP-11 Digital computer (Digital Equipment Corp.,
Maynard, Mass.) for on-line calculation of R.sub.L from
transpulmonary pressure, respiratory volume obtained by integration
and flow. Analysis of 10-15 breaths is used for the determination
of R.sub.L. Thoracic gas volume (V.sub.tg) is measured in a body
plethysmograph, to obtain specific pulmonary resistance
(SR.sub.L=R.sub.LV.sub.tg).
[0088] The following examples are provided to illustrate the
invention and are not to be construed as limiting the scope of the
invention in any manner. In the examples, unless otherwise stated,
[0089] all the end products of the formula I were analyzed by NMR,
TLC and elementary analysis or mass spectroscopy; [0090]
intermediates were analyzed by NMR and TLC; [0091] most compounds
were purified by flash chromatography on silica gel,
recrystallization and/or swish (suspension in a solvent followed by
filtration of the solid); [0092] the course of reactions was
followed by thin layer chromatography (TLC) and reaction times are
given for illustration only; [0093] the enantiomeric excess was
measured on normal phase HPLC with a chiral column: ChiralPak AD;
250.times.4.6 mm.
[0094] The following intermediates were prepared according to
literature procedures or purchased from the following vendor:
[0095] Ethyl 2-(2-oxocyclopentyl)acetate: Acros/Fisher Scientific.
[0096] 4-fluoro-2-iodoaniline: Beugelmans, R.; Chbani, M. Bull.
Soc. Chim. Fr. 1995, 132, 306-313.
Example 1
(3R)-[4-(4-chlorobenzyl)-7-fluoro-5-(methanesulfonyl)-1,2,3,4-tetrahydrocy-
clopenta[b]indol-3-yl]acetic acid
##STR00014##
[0097] Step 1:
(+/-)-(7-Fluoro-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl)acetic
acid ethyl
##STR00015##
[0099] A solution of 10.00 g of 4-fluoro-2-iodoaniline, 6.57 g of
ethyl 2-(2-oxocyclopentyl)acetate and 121 mg of p-toluenesulfonic
acid in 100 ml of benzene was refluxed with a Dean-Stark trap under
a N.sub.2 atmosphere for 24 h. After this time, the benzene was
removed under distillation. Then, 60 ml of DMF was added and the
solution was degassed before 19 ml of Hunig's base followed by 405
mg of Pd(OAc).sub.z were added successively. The solution was
heated to 115.degree. C. for 3 h, then cooled to room temperature.
To quench the reaction, 300 ml of 1 N HCl and 200 ml of ethyl
acetate were added and the mixture was filtered through Celite. The
phases were separated and the acidic phase was extracted twice with
200 ml of ethyl acetate. The organic layers were combined, washed
with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered through
Celite and concentrated. The crude material was further purified by
flash chromatography eluting with 100% toluene to provide 5.36 g of
the title compound as a yellow solid.
[0100] .sup.1H NMR (acetone-d.sub.6) .delta. 9.76 (br s, 1H), 7.34
(dd, 1H), 7.03 (d, 1H), 6.78 (td, 1H), 4.14 (q, 2H), 3.57 (m, 1H),
2.85-2.55 (m, 5H), 2.15 (m, 1H), 1.22 (t, 3H).
Step 2:
(+/-)-(7-Fluoro-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl)acetic
acid
##STR00016##
[0102] To a solution of 1.24 g of the ester from Step 1 in 14 mL of
tetrahydrofuran (THF) at room temperature, 7 mL of MeOH followed by
7 mL of 2N NaOH were added. After 2.5 h, the reaction mixture was
poured into a separatory funnel containing ethyl acetate (EtOAc)/1
N HCl. The phases were separated and the acidic phase was extracted
twice with EtOAc. The organic layers were combined, washed with
brine, dried over anhydrous Na.sub.2SO.sub.4 and evaporated to
dryness to yield 1.08 g of a crude and unstable waxy brown oil that
was used as such in the next step (>90% purity).
[0103] .sup.1H NMR (acetone-d.sub.6) .delta. 10.90 (br s, 1H), 9.77
(br s, 1H), 7.34 (dd, 1H), 7.04 (dd, 1H), 6.79 (td, 1H), 3.56 (m,
1H), 2.90-2.50 (m, 5H), 2.16 (m, 1H). MS (-APCI) m/z 232.2
(M-H).sup.-.
Step 3:
(+/-)-(5-bromo-7-fluoro-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl)-
acetic acid
##STR00017##
[0105] To a solution of 2.20 g of the acid from Step 2 (>90%
purity) in 30 mL of pyridine, 6.85 g of pyridinium tribromide (90%
purity) was added at -40.degree. C. The suspension was stirred for
10 min at 0.degree. C. and warmed to room temperature for 30 min.
Then, the solvent was removed without heating under high vacuum.
The crude material was dissolved in 40 mL of AcOH and 2.88 g of Zn
dust was added portion wise to the cold solution at 0.degree. C.
The suspension was stirred for 15 min at 15.degree. C. and warmed
to room temperature for an additional 15 min. At this time, the
reaction mixture was quenched by the addition of 1 N HCl and this
mixture was poured into a separatory funnel containing brine/EtOAc.
The layers were separated and the organic layer was washed with
water, brine, dried over anhydrous Na.sub.2SO.sub.4 and
concentrated. This material was used without further purification
in the next step.
[0106] .sup.1H NMR (acetone-d.sub.6) .delta. 10.77 (br s, 1H), 9.84
(br s, 1H), 7.09 (m, 2H), 3.60 (m, 1H), 2.95-2.65 (m, 4H), 2.56
(dd, 1H), 2.19 (m, 1H).
Step 4:
(+/-)-[5-bromo-4-(4-chlorobenzyl)-7-fluoro-1,2,3,4-tetrahydrocyclo-
penta[b]-indol-3-yl]acetic acid
##STR00018##
[0108] To a solution of 2.13 g of the acid from Step 3 in 10 mL of
THF, a solution of diazomethane in ether was added in excess until
complete consumption of the acid as monitored on TLC. Then, the
solvents were removed under vacuum. To a solution of the crude
methyl ester thus formed in 20 mL of DMF, 539 mg of a NaH
suspension (60% in oil) was added at -78.degree. C. The suspension
was stirred for 10 min at 0.degree. C., cooled again to -78.degree.
C. and treated with 1.70 g of 4-chlorobenzyl bromide. After 5 min,
the temperature was warmed to 0.degree. C. and the mixture was
stirred for 20 min. At this time, the reaction was quenched by the
addition of 2 mL of AcOH and this mixture was poured into a
separatory funnel containing 1 N HCl/EtOAc. The layers were
separated and the organic layer was washed with brine, dried over
anhydrous Na.sub.2SO.sub.4 and concentrated. The alkylated material
was hydrolyzed using the procedure described in Step 2. The crude
material was further purified by trituration with EtOAc/hexanes to
yield 2.35 g of the title compound as a pale brown solid.
[0109] .sup.1H NMR (acetone-d.sub.6) .delta. 10.70 (br s, 1H), 7.31
(d, 2H), 7.18 (d, 1H), 7.06 (d, 1H), 6.92 (d, 2H), 5.90 (d, 1H),
5.74 (d, 1H), 3.61 (m, 1H), 3.00-2.70 (m, 3H), 2.65 (dd, 1H), 2.39
(dd, 1H), 2.26 (m, 1H). MS (-APCI) m/z 436.3, 434.5
(M-H).sup.-.
Step 5:
(+)-[5-bromo-4-(4-chlorobenzyl)-7-fluoro-1,2,3,4-tetrahydrocyclope-
nta[b]-indol-3-yl]acetic acid
##STR00019##
[0111] To a solution of 2.35 g of the acid of Step 4 in 130 mL of
EtOH at 80.degree. C., was added 780 .mu.L of
(S)-(-)-1-(1-naphthyl)ethylamine. The solution was cooled to room
temperature and stirred overnight. The salt recovered (1.7 g) was
recrystallized again with 200 mL of EtOH. After filtration, the
white solid salt obtained was neutralized with 1 N HCl and the
product was extracted with EtOAc. The organic layer was washed with
brine, dried over anhydrous Na.sub.2SO.sub.4 and concentrated. The
material was filtered over a pad of SiO.sub.2 by eluting with EtOAc
to yield 500 mg of the title enantiomer as a white solid. Retention
times of the two enantiomers were respectively 7.5 min and 9.4 min
[ChiralPak AD column, hexane/2-propanol/acetic acid (95:5:0.1)].
The more polar enantiomer was in 98% ee. ee=98%; Retention time=9.4
min [ChiralPak AD column: 250.times.4.6 mm,
hexanes/2-propanol/acetic acid (75:25:0.1)];
[.alpha.].sub.D.sup.21=+39.2.degree. (c 1.0, MeOH).
Step 6:
(3R)-[4-(4-chlorobenzyl)-7-fluoro-5-(methanesulfonyl)-1,2,3,4-tetr-
ahydro-cyclopenta[b]indol-3-yl}acetic acid and sodium salt
[0112] The acid from Step 5 (15.4 g) was first esterified with
diazomethane. The sulfonylation was accomplished by mixing the
ester thus formed with 16.3 g of methanesulfinic acid sodium salt
and 30.2 g of CuI (I) in N-methylpyrrolidinone. The suspension was
degassed under a flow of N.sub.2, heated to 150.degree. C. and
stirred for 3 h, then cooled to room temperature. To quench the
reaction, 500 ml of ethyl acetate and 500 ml of hexanes were added
and the mixture was filtered through a pad of SiO.sub.2 by eluting
with EtOAc. The organic phases were concentrated. The crude oil was
dissolved with EtOAc, washed three times with water one time with
brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and
concentrated. The crude material was further purified by flash
chromatography eluting with a gradient from 100% toluene to 50%
toluene in EtOAc to provide 14 g of the sulfonated ester, which was
hydrolyzed using the procedure described in Step 2. The title
compound (9.8 g) was obtained as a white solid after two successive
recrystallizations: isopropyl acetate/heptane followed by
CH.sub.2Cl.sub.2/hexanes.
[0113] .sup.1H NMR (500 MHz acetone-d.sub.6) .delta. 10.73 (br s,
1H), 7.57 (d, 2H, J=8.8 Hz), 7.31 (m, 1H), 7.29 (m, 1H), 6.84 (d,
2H, J=8.8 Hz), 6.29 (d, 1H, J.sub.AB=17.8 Hz), 5.79 (d, 1H,
J.sub.AB=17.8 Hz), 3.43 (m, 1H), 2.98 (s, 3H), 2.94 (m, 1H),
2.85-2.65 (m, 3H), 2.42 (dd, 1H, J.sub.1=16.1 Hz, J.sub.2=10.3 Hz),
2.27 (m, 1H). .sup.13C NMR (125 MHz acetone-d.sub.6) .delta. 173.0,
156.5 (d, J.sub.CF=237 Hz), 153.9, 139.2, 133.7, 133.3, 130.0 (d,
J.sub.CF=8.9 Hz), 129.6, 128.2, 127.5 (d, J.sub.CF=7.6 Hz), 122.2
(d, J.sub.CF=4.2 Hz), 112.3 (d, J.sub.CF=29.4 Hz), 111.0 (d,
J.sub.CF=22.6 Hz), 50.8, 44.7, 38.6, 36.6, 36.5, 23.3. MS (-APCI)
m/z 436.1, 434.1 (M-H).sup.-.
[0114] ee=97%; Retention time=15.3 min [ChiralCel OD column:
250.times.4.6 mm, hexanes/2-propanol/ethanol/acetic acid
(90:5:5:0.2)]; [.alpha.].sub.D.sup.21=-29.3.degree. (c 1.0, MeOH).
Mp 175.0.degree. C.
[0115] The sodium salt was prepared by the treatment of 6.45 g
(14.80 mmol) of the above acid compound in EtOH (100 mL) with 14.80
mL of an aqueous 1N NaOH solution. The organic solvent was removed
under vacuum and the crude solid was dissolved in 1.2 L of
isopropyl alcohol under reflux. The final volume was reduced to 500
mL by distillation of the solvent. The sodium salt crystallized by
cooling to rt. The crystalline sodium salt was suspended in
H.sub.2O, frozen with a dry ice bath and lyophilized under high
vacuum to give 6.00 g of the title compound as the sodium salt.
[0116] .sup.1H NMR (500 MHz DMSO-d.sub.6) .delta. 7.63 (dd, 1H,
J.sub.1=8.5 Hz, J.sub.2=2.6 Hz), 7.47 (dd, 1H, J.sub.1=9.7 Hz,
J.sub.2=2.6 Hz), 7.33 (d, 2H, J=8.4 Hz), 6.70 (d, 2H, J=8.4 Hz),
6.06 (d, 1H, J.sub.AB=17.9 Hz), 5.76 (d, 1H, J.sub.AB=17.9 Hz),
3.29 (m, 1H), 3.08 (s, 3H), 2.80 (m, 1H), 2.69 (m, 1H), 2.55 (m,
1H), 2.18 (m, 2H), 1.93 (dd, 1H, J.sub.1=14.4 Hz, J.sub.2=9.7
Hz).
Example 1A
Alternative procedure for
(+/-)-[5-bromo-4-(4-chlorobenzyl)-7-fluoro-1,2,3,4-tetrahydrocyclopenta[b-
]indol-3-yl]acetic acid (Example 1, Step 4)
Step 1:
(+/-)-7-fluoro-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl)acetic
acid dicyclohexylamine (DCHA) salt
[0117] A 0.526 M solution of 2-bromo-4-fluoroaniline in xylene
along with ethyl (2-oxocyclopentyl)acetate (1.5 eq) and sulfuric
acid (0.02 eq) was heated to reflux for 20 hours. Water was
azeotropically removed with a Dean-Stark apparatus. The reaction
was followed by NMR and after 20 hours, a 80-85% conversion to the
desired imine intermediate was generally observed. The reaction
mixture was washed with 1M sodium bicarbonate (0.2 volumes) for 15
minutes and the organic fraction was evaporated. The remaining
syrup was distilled under vacuum (0.5 mm Hg). Residual xylenes
distilled at 30.degree. C., then excess ketone and unreacted
aniline were recovered in 50-110.degree. C. range; the imine was
recovered in the 110-180.degree. C. fraction as a light brown clear
liquid with 83% purity.
[0118] The imine intermediate was then added to a degased mixture
of potassium acetate (3 eq), tetra-n-butylammonium chloride
monohydrate (1 eq), palladium acetate (0.03 eq) and
N,N-dimethylacetamide (final concentration of imine=0.365 M). The
reaction mixture was heated to 115.degree. C. for 5 hours and
allowed to cool to room temperature. 3N KOH (3 eq) was then added
and the mixture was stirred at room temperature for 1 hour. The
reaction mixture was diluted with water (1.0 volume), washed with
toluene (3.times.0.75 volume). The aqueous phase was acidified to
pH 1 with 3N HCl and extracted with tertbutyl methyl ether
(2.times.0.75 volume). The combined organic fractions were washed
with water (0.75 volume). To the clear light brown solution was
added dicyclohexylamine (1 eq) and the solution was stirred at room
temperature for 16 hours. The salt was filtered, washed with ethyl
acetate, tertbutyl methyl ether and allowed to dry to give the
title compound as a tan solid.
[0119] Assay: 94 A %.
[0120] .sup.1H NMR (500 mHz, CDCl3): .delta. 9.24 (s, 1H),
7.16-7.08 (m, 2H), 6.82 (t, 1H), 6.2 (br, 2H), 3.6-3.5 (m, 1H),
3.04-2.97 (m, 2H), 2.88-2.70 (m, 3H), 2.66 (dd, 1H), 2.45-2.37 (m,
1H), 2.13-2.05 (m, 2.05), 1.83 (d, 4H), 1.67 (d, 2H), 1.55-1.43 (m,
4H), 1.33-1.11 (m, 6H).
Step 2:
(+/-)-(5-bromo-7-fluoro-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl)-
acetic acid
[0121] A slurry of the DCHA salt from Step 1 above in
dichloromethane (0.241 M solution) was cooled to -20 to -15.degree.
C. Pyridine (2 eq.) was added in one shot and to the slurry was
added dropwise bromine (2.5 eq.) over 30 to 45 minutes maintaining
the temperature between -20.degree. C. and -15.degree. C. (At about
1/3 addition of bromine, the reaction mixture was thick and an
efficient stirring was needed. Eventually, at about 1/2 addition of
bromine, the mixture became "loose" again.)
[0122] After completion of the addition, the reaction mixture was
aged for one additional hour at -15.degree. C. Acetic acid (3.04
eq.) was then added over 5 minutes and zinc dust (3.04 eq.) was
added portion wise. (A portion of zinc was added at -15.degree. C.
and the mixture was aged for about 5 minutes to ensure that the
exotherm was going (about -15.degree. C. to -10.degree. C.)). This
operation was repeated with about 5 shots of zinc over about 30
min. When no more exotherm was observed, the remaining zinc was
added faster. The whole operation takes around 30 to 45
minutes.
[0123] After completion of the addition, the batch was warmed to
room temperature, aged 1 hour and concentrated. The reaction
mixture was switched to methyl t-butyl ether (MTBE, 0.8 volume) and
a 10% aqueous acetic acid solution (0.8 volume) was added. The
mixture (crystallization of salts, e.g. pyridium) was aged at room
temperature for 1 hour and filtered through solka-floc. The pad of
solka-floc was rinsed with MTBE (ca. 0.2 volume) and the filtrate
(biphasic, MTBE/aqueous) was transferred into an extractor. The
organic phase was washed with water (0.8 volume). The MTBE extract
was concentrated and switched to isopropyl alcohol (IPA, 0.25
volume) to crystallize the compound. water (0.25 volumes) was added
and the batch was aged for 1 hour. Additional water (0.33 volumes)
was added over 1 hour. After completion of the water addition, the
batch was aged for one additional hour, filtered, and rinse with
30/70 IPA/Water (0.15 volumes). Crystallized bromoacid was dried in
the oven at +45.degree. C.
Step 3:
(+/-)-[5-bromo-4-(4-chlorobenzyl)-7-fluoro-1,2,3,4-tetrahydrocyclo-
penta[b]-indol-3-yl]acetic acid
[0124] The bromoacid of Step 2 was dissolved in dimethylacetamide
(0.416 M solution) and cesium carbonate (2.5 eq.) was added in one
portion. To the slurry was added in one portion 4-chlorobenzyl
chloride (2.5 eq.) and the batch was heated to 50.degree. C. for 20
h. The batch was cooled to r.t. and sodium hydroxide 5N (4.00 eq.)
was added over 5 minutes (temperature rises to +40.degree. C.). The
reaction was aged at 50.degree. C. for ca. 3 hours, cooled to room
temperature and transferred into an L extractor. The solution was
diluted with isopropylacetate (IPAc, 2 volumes) and cooled to
+15.degree. C. The solution was acidified with 5N HCl to
pH.about.2. Layers are separated and the organic layer was washed
with water (2.times.2 volumes). IPAc solution was concentrated and
switched to IPA (0.8 volumes) to crystallize the product. Water (8
L) was added over 2 hours and the batch was filtered to give the
title compound in 88% isolated yield. The batch can be dried in the
oven at +40.degree. C. for 24 hours.
Example 2
(+/-)-{4-[1-(4-chlorophenyl)ethyl]-7-fluoro-5-methanesulfonyl-1,2,3,4-tetr-
ahydro-cyclopenta[B]indol-3-yl}acetic acid
##STR00020##
[0126] To a solution of 1.5 g of the methyl ester of the acid of
Example 1, Step 3 (which was prepared by esterification of the
corresponding acid with diazomethane in tetrahydrofuran), 2.03 g of
1-(1-bromoethyl)-4-chlorobenzene in 50 mL of acetonitrile and 6.01
g of cesium carbonate was added. The resulting mixture was heated
to reflux with rigorous stirring for 3 hr. Then the reaction
mixture was cooled to room temperature, diluted with 50 mL of ethyl
acetate, filtered, and the solvent evaporated. The residue was
purified by flash chromatography (silica gel, 4% EtOAc/hexane) to
afford 1.41 g of desired N-benzylation product as an approximate
1:1 mixture of diastereomers according to .sup.1H NMR analysis.
[0127] To the above ester (1.2 g) dissolved in 80 mL of NMP, 2.63 g
of methanesulfinic acid sodium salt and 3.7 g of Cu(I) Br was added
successively. The resulting suspension was degassed under a flow of
N.sup.2, heated to 140.degree. C. and stirred rigorously for 8 h.
Then the reaction mixture was cooled to room temperature and
diluted with 500 ml of ethyl acetate and 500 ml of hexane. The
resulting mixture was filtered through a pad of silica gel, further
eluted with EtOAc. The filtrate was concentrated to about 300 mL of
volume and washed with water and brine. The organic phase was
separated and dried over anhydrous Na.sub.2SO.sub.4, filtered, and
concentrated. The crude material was further purified by flash
chromatography over silica gel eluting with 30% EtOAc/hexane to
provide 1.0 g of the sulfonated material. It was hydrolyzed to its
corresponding acid using 10 mL of 2 N NaOH in a solvent mixture
composed of 10 mL of THF and 10 mL of MeOH at rt for 3 h. The
reaction mixture was neutralized with 1 M HCl aqueous solution and
extracted with EtOAc. The separated organic phase was dried over
anhydrous sodium sulfate, filtered, and evaporated to afford the
crude acid. The two diastereomers were separated by using
preparative HPLC (Zobax, 30% EtOAC/hexane with 0.2% AcOH) to afford
300 mg of diastereomer A (shorter retention time) and 210 mg of
diastereomer B (longer retention time).
[0128] Diastereomer B: .sup.1H NMR (acetone-d.sub.6) .delta. 10.70
(br s, 1H), 7.66 (dd, 1H), 7.56 (dd, 1H), 7.32 (d, 2H), 6.95 (d,
2H), 6.91 (q, 1H), 3.39 (s, 3H), 3.05-3.00 (m, 1H), 2.90-2.75 (m,
2H), 2.70 (dd, 1H), 2.44 (dd, 1H), 2.43-2.34 (m, 1H), 2.21 (dd,
1H), 2.11 (d, 3H). MS (-APCI) m/z 448.0 (M-H).sup.-.
Example 2A
Alternative Synthesis of
(+/-)-4-[1-(4-chlorophenyl)ethyl]-7-fluoro-5-methane-sulfonyl-1,2,3,4-tet-
rahydro-cyclopenta[b]indol-3-yl}acetic acid
[0129] To a solution of 6.52 g of the methyl ester of the acid of
Example 1, Step 3 (which was prepared by esterification of the
corresponding acid with diazomethane in tetrahydrofuran) in 160 mL
of NMP, 10.2 g of methanesulfinic acid sodium salt and 19 g of CuI
was added successively. The resulting suspension was degassed under
a flow of N.sub.2, heated to 150.degree. C. and stirred rigorously
for 4 h. Then the reaction mixture was cooled to room temperature
and diluted with 500 ml of ethyl acetate and 500 ml of hexane. The
resulting mixture was filtered through a pad of silica gel, further
eluted with EtOAc. The filtrate was concentrated to about 300 mL of
volume and washed with water and brine. The organic phase was
separated and dried over anhydrous Na.sub.2SO.sub.4, filtered, and
concentrated. The crude material was further purified by flash
chromatography over silica gel eluting with 30% EtOAc/hexane to
provide 4.7 g of the sulfonated material, which was dissolved in
200 mL of dichloromethane. To the resulting solution, 3.39 g of
4-chlorophenyl methyl carbinol and 5.68 g of triphenylphosphine was
added, followed by the portion-wise addition of 4.99 g of
di-tert-butyl azodicarboxylate. The reaction mixture was stirred at
rt for 3 h and then concentrated. The residue was loaded on a
silica gel column and eluted with 5% EtOAc/hexane to afford 5.1 g
of methyl ester of the title compound as an approximately 1:1
mixture of diastereomers according to .sup.1H NMR analysis.
Following the hydrolysis and purification step described in Example
2, the title acid was afforded.
Example 3
(+/-)-[9-(4-chlorobenzyl)-6-fluoro-8-methanesulfonyl-2,3,4,9-tetrahydro-1H-
-CARBAZOL-1-yl]acetic acid
##STR00021##
[0130] Step 1: (+/-)-ethyl
(8-bromo-6-fluoro-2,3,4,9-tetrahydro-1H-carbazol-1-yl)acetate
##STR00022##
[0132] To a suspension of 7.24 g of
(2-bromo-4-fluorophenyl)hydrazine hydrochloric acid salt in 100 mL
of acetic acid, 5.5 g of ethyl 2-(2-oxocyclohexyl)-acetate was
added. The resulting mixture was heated to reflux for 1 h. Then 10
mL of ethanol was added and the reaction mixture was heated at
reflux overnight. The solvent was evaporated and the residue was
diluted with EtOAc and washed with saturated aqueous NaHCO.sub.3
solution, water, and brine successively. The organic layer was
separated and dried over anhydrous sodium sulfate, filtered, and
evaporated. The residue was purified by flash chromatography over
silica gel (5% EtOAc/hexane) to afford 3.12 g of desired
compound.
[0133] .sup.1H NMR (acetone-d.sub.6) .delta. 9.97 (br s, 1H), 7.34
(dd, 1H), 7.13 (dd, 1H), 7.09 (dd, 1H), 4.16 (q, 2H), 3.43-3.35 (m,
5H), 3.05-2.88 (m, 1H), 2.76-2.53 (m, 3H), 2.10-2.00 (m, 1H),
1.96-1.87 (m, 1H), 1.82-1.72 (m, H), 1.72-1.64 (m, 1H), 1.23 (t,
3H).
Step 2:
(+/-)-Ethyl[8-Bromo-9-(4-chlorobenzyl)-6-fluoro-2,3,4,9-tetrahydro-
-1H-carbazol-1-yl]acetate
##STR00023##
[0135] To a solution of 3.12 g of the ester prepared in step 1 and
3.62 g of 1-bromomethyl-4-chlorobenzene in 30 mL of acetonitrile,
5.74 g of cesium carbonate was added. The resulting mixture was
stirred rigorously at reflux for 3 hr. Then it was cooled to room
temperature, diluted with minimum amount of EtOAc, filtered, and
evaporated. The residue was purified by flash chromatography over
silica gel (50% toluene/hexane) to afford 4.1 g of the title
compound.
[0136] .sup.1H NMR (acetone-d.sub.6) .delta. 7.32 (d, 2H), 7.24
(dd, 1H), 7.13 (dd, 1H), 6.86 (d, 2H), 6.00 and 5.65 (AB q, 2H),
4.15-4.05 (m, 2H), 3.44-3.35 (m, 1H), 2.88-2.76 (m, 1H), 2.65-2.52
(m, 3H), 2.00-1.80 (m, 4H), 1.22 (t, 3H).
Step 3:
(+/-)-[9-(4-Chlorobenzyl)-6-fluoro-8-methanesulfonyl-2,3,4,9-tetra-
hydro-1H-carbazol-1-yl]acetic acid
[0137] To a solution of 478 mg of the ester prepared in step 2 in 8
mL of NMP, 510 mg of methanesulfinic acid sodium salt and 950 mg of
CuI (I) was added successively. The resulting mixture was degassed
under a flow of N.sub.2, then heated at 140.degree. C. for 8 h
under rigorous stirring. The reaction mixture was cooled to room
temperature, diluted with minimum amount of a 1:1 mixture of
EtOAc/hexane. The resulting mixture was filtered through a pad of
silica gel, further eluted with EtOAc. The filtrate was
concentrated to about 50 mL, and washed with water and brine. The
organic phase was collected, dried over anhydrous sodium sulfate,
filtered, and evaporated. The residue was purified by flash
chromatography over silica gel (30% EtOAc/hexane) to afford 320 mg
of desired sulfonated material, which was dissolved in 5 mL of THF
plus 5 mL of methanol. To the resulting solution, 5 mL of 2 N of
NaOH was added and the resulting mixture was stirred at rt for 6 h.
The reaction mixture was neutralized with 1 M HCl aqueous solution
and extracted with EtOAc. The separated organic phase was dried
over anhydrous sodium sulfate, filtered, and evaporated. The
residue was refluxed with hexane under rigorous stirring for 0.5 h.
The resulting mixture was cooled to rt under rigorous stirring, and
filtered to afford 278 mg of desired acid.
[0138] .sup.1H NMR (500 MHz acetone-d.sub.6) .delta. 10.73 (br s,
1H), 7.57 (d, 1H), 7.56 (d, 1H), 7.29 (d, 1H), 6.67 (d, 2H,), 6.47
and 5.61 (AB q, 2H), 3.27-3.21 (m, 1H), 2.98 (s, 3H), 2.85 (dd,
1H), 2.76-2.55 (m, 3H), 2.00-1.84 (m, 3H), 1.82-1.73 (m, 1H). MS
(-APCI) m/z 448.0 (M-H).sup.-.
Example 4
[4-(4-chlorobenzyl)-7-fluoro-5-methanesulfonyl-1-oxo-1,2,3,4-tetrahydrocyc-
lopenta[b]indol-3-yl]acetic acid
##STR00024##
[0139] Step 1:
[5-Bromo-4-(4-chlorobenzyl)-7-fluoro-1-oxo-1,2,3,4-tetrahydro-cyclopenta[-
b]indol-3-yl]acetic acid methyl ester
##STR00025##
[0141] The methyl ester of the compound of Example 1 step 5 (1.00
g, prepared by treating the corresponding acid with excess
diazomethane) in 10 mL of a 9:1 THF/H.sub.2O solution was treated
with 2.52 g of DDQ. The reaction mixture was allowed to stir at
room temperature overnight. The reaction mixture at this time was
poured into a separatory funnel containing EtOAc and brine. The
combined organic layers were washed with water, brine, dried over
anhydrous MgSO.sub.4 and concentrated. The resulting material was
further purified by flash chromatography eluting with 30%
EtOAc/hexane. The chromatography procedure was repeated an
additional two times. 350 mg of the above ketone was obtained as a
grey solid.
Step 2:
[4-(4-chlorobenzyl)-7-fluoro-5-methanesulfonyl-1-oxo-1,2,3,4-tetra-
hydro-cyclopenta[b]indol-3-yl]acetic acid
[0142] The bromide from Step 1 (200 mg) in 4 mL of NMP was treated
with 320 mg of CuI and 175 mg of CH.sub.3 SO.sub.2Na. Nitrogen was
bubbled through the reaction mixture for approximately one minute
and then the mixture was heated for six hours at 130.degree. C. At
this time the reaction mixture was cooled to room temperature,
diluted with EtOAc and filtered through a pad of silica gel, the
residue was rinsed with additional EtOAc. The organic layers were
washed with water, brine, dried over anhydrous MgSO.sub.4 and
concentrated. The resulting oil was purified by flash
chromatography eluting with 50% EtOAc/hexane and obtained 54 mg of
the corresponding methyl sulphone as an off-white solid.
[0143] The above methyl ester in 5 mL of THF/H.sub.2O (1:1) and 5
mL of MeOH was treated with 1 mL of a 1 N HCl solution. This
mixture was stirred at room temperature for two hours. At this time
the reaction mixture was acidified with a 1 N HCl solution and
poured into a separatory funnel containing water and EtOAc. The
layers were separated and the aqueous layer was extracted EtOAc.
The combined organic layers were washed with water, brine, dried
over anhydrous Na.sub.2SO.sub.4 and concentrated. The resulting
material was further purified by flash chromatography eluting with
100% EtOAc containing 1% AcOH and 26 mg of the title acid was
obtained as an off white solid.
[0144] .sup.1H NMR (500 MHz, acetone-d.sub.6) .delta. 11.0 (br,
1H), 7.85 (m, 1H), 7.80 (m, 1H), 7.38 (d, J=8 Hz, 2H), 7.04 (d, J=8
Hz, 2H), 6.42 (d, J.sub.AB=18 Hz, 1H), 6.08 (d, J.sub.AB=18 Hz,
1H), 3.78 (m, 1H), 3.28 (m, 1H), 3.10 (m, 1H), 3.05 (s, 3H), 2.65
(m, 2H). MS (-APCI) m/z 448.2 (M-H)--.
* * * * *