Title of Invention

PROCESS FOR THE PREPARATION OF ISOOXAZOLE COMPOUNDS AND 2-ISOOXAZOLINES

Abstract The invention discloses a process for the preparation of a compound of the formula (I), wherein R1, Y and Z are as defined in the specification. the process comprising: contacting an oxime of the formula III with an oxidizing agent and reacting the resulting nitrile oxide with an alkyne of the formula IV The invention is also for 2-isooxazolines of formula (IX). wherein R1, Y and Z are as defined in the specification and process for its preparation.
Full Text PROCESS FOR THE PREPARATION OF ISOOXAZOLE
COMPOUNDS AND 2-ISOOXAZOLINES
This application claims the benefit of the priority of United States Provisional
Patent Application No. 60/328,901, filed October 12, 2001, the disclosure of which is
hereby incorporated by reference as if fully set forth herein.
The present invention relates to substituted isoxazoles and 2-isoxazolines, and
processes for their preparation. In addition the invention relates to compounds that serve
as useful intermediates in the preparation of these heterocycles. Substituted isoxazoles
are useful in the treatment of inflammation and inflammation-related disorders, including
arthritis.
Selective inhibitors of cyclooxygenase-2 (COX-2) have demonstrated effective
anti-inflammatory activity. Other antiinflammatory agents, e.g., NSAIDs, inhibit both
the constitutive form of cyclooxygenase (COX-1), and the inducible form of the enzyme,
COX-2.
COX-1 is a constitutive cyclooxygenase isoform and is mainly responsible for the
synthesis of cytoprotective prostaglandins in the GI tract and the synthesis of
thromboxane which triggers platelet aggregation in blood platelets. COX-2 is inducible
and short-lived except in the case of certain tumors where it is constitutively activated.
COX-2 expression is stimulated in response to endotoxins, cytokines, hormones, growth
factors and mitogens. These observations suggest that COX-1 and COX-2 serve
different physiological and pathophysiological functions. It has been suggested that
COX-2 activity is mainly responsible for the pathological effects of prostaglandins where
induction of the enzyme occurs in response to inflammatory agents, hormones, growth
factors and cytokines. United States Patent No. 5,604,253, incorporated herein by
reference, for a discusses the advantages of selective COX-2 inhibition. Principally, a
selective COX-2 inhibitor is expected to possess similar antiinflammatory, antipyretic
and analgesic properties to conventional NSAIDs but with reduced potential for
gastrointestinal toxicity, and a reduced potential for renal side effects.
A particularly effective structural class of selective COX-2 inhibitors are the 3,4-
diaryl-substituted isoxazoles. For example, the compound, 4-[5-methyl-3-phenyl-
isoxazol-l-yl]benzenesulfonamide (also known as Valdecoxib®) is useful for the
treatment of a number of inflammation disorders, including osteoarthritis and rheumatoid
arthritis. In addition, the sodium salt of N-[[(5-methyl-3-phenylisoxazol-4-yl)-

phenyl]sulfonyl]propanamide (also known as Parecoxib®), a prodrug of Valdecoxib®, is
particularly effective in parenteral compositions for acute pain management.

Talley et al. (United States Patent No. 5,932,598 and J. Med. Chem. 2000, 43,
775-777) disclose the preparation of Valdecoxib® and related derivatives from
deoxybenzoin. In the preparation, deoxybenzoin is treated with hydroxylamine, and the
resulting oxime is deprotonated and condensed with an ester, e.g., ethyl acetate, to form
an isoxazoline intermediate. The isoxazoline intermediate is converted to Valdecoxib®
by treatment with chlorosulphonic acid, followed by aqueous ammonia. Parecoxib
sodium® can be prepared by acylation of Valdecoxib® with propionic anhydride (Talley
et al., J. Med. Chem. 2000, 43, 1661-1663).
Also of interest for their COX-2 inhibitory activity and antiinflammatory activity
are closely related analogs of Valdecoxib®, as well as processes for their preparation.
Summary of the Invention
In one embodiment, the invention relates to a process for the preparation of a
compound of the formula I
wherein R1 is selected from the group consisting of hydrogen, trihalomethyl, preferably
trifluoromethyl; C1-C6 alkyl, preferably C1-C3 alkyl, most preferably methyl; and a group
of the formula II


wherein R3 and R4 are independently selected from the group consisting of
hydrogen; amino; halogen; preferably chlorine, fluorine and bromine;
hydroxyl; nitro; C1-C6 alkyl, preferably C1-C3 alkyl; C1-C6 alkoxy, preferably
C1-C3 alkoxy; carboxy; C1-C6 trihaloalkyl, preferably trihalomethyl, most
preferably trifluoromethyl; cyano; alkylsulfonyl; sulfamyl; phosphonato; and
hydroxyalkyl, preferably C1-C6 hydroxyalkyl;
Y is a group of the formula
wherein
R2 is selected from the group consisting of C1-C6 alkyl, preferably C1-C3 alkyl;
C1-C6 alkanoylamino; and amino; and
R5 is selected from the group consisting of hydrogen; amino; halogen; preferably
chlorine, fluorine and bromine; hydroxyl; nitro; C1-C6 alkyl, particularly C1-C3 alkyl; C1-C6 alkoxy, particularly C1-C3 alkoxy, preferably methoxy;
carboxy; C1-C6 trihaloalkyl, preferably trihalomethyl, most preferably
trifluoromethyl; cyano, phosphonato, and hydroxyalkyl, preferably C1-C6
hydroxyalkyl; and
Z is selected from the group consisting of substituted and unsubstituted aryl.
The process has the step of contacting an oxime of the formula III

with an oxidizing agent and reacting the resulting nitrile oxide with an alkyne of the
formula IV
In another embodiment, the invention relates to a compound of the formula IX


and pharmaceutically acceptable salts thereof, wherein R1 is selected from the group
consisting of hydrogen; trihalomethyl, preferably trifluoromethyl; C1-C6 alkyl, preferably
C1-C3 alkyl, most preferably methyl; and a group of the formula II

wherein R3 and R4 are independently selected from the group consisting of
hydrogen; amino; halogen, preferably chlorine, fluorine and bromine;
hydroxyl; nitro; C1-C6 alkyl, preferably C1-C3 alkyl; C1-C6 alkoxy, preferably
C1-C3 alkoxy; carboxy; C1-C6 trihaloalkyl, preferably trihalomethyl, most
preferably trifluoromethyl; cyano; alkylsulfonyl; sulfamyl; phosphonato; and
hydroxyalkyl;
Y is a group of the formula
wherein
R2 is selected from the group consisting of C1-C6 alkyl, preferably C1-C3 alkyl;
t
C1-C5 alkanoylamino; and amino; and
R5 is selected from the group consisting of hydrogen; amino; halogen; preferably
chlorine, fluorine and bromine; hydroxyl; nitro; C1-C6 alkyl, particularly C1-
C3 alkyl; C1-C6 alkoxy, particularly C1-C3 alkoxy, preferably methoxy;
carboxy; C1-C6 trihaloalkyl, preferably trihalomethyl, most preferably
trifluoromethyl; cyano; phosphonato, and hydroxyalkyl, preferably C1-C6
hydroxyalkyl; and
Z is selected from the group consisting of substituted and unsubstituted aryl.
In preferred embodiments of the compound of formula DC, R2 is amino. In
particularly preferred embodiments, R2 is amino or propionylamino, R1 is methyl, R5 is
hydrogen and Z is phenyl.
In other preferred embodiments of the compound of formula IX, R is C1-C6
alkanoylamino, preferably n-propionylamino. In particularly preferred embodiments, R2
is propionylamino, Rl is methyl, R5 is hydrogen and Z is phenyl.

The invention is also directed to isolated optical isomers of compounds according
to formulas IX. By "isolated" means a compound which has been substantially purified
from the corresponding optical isomer(s) of the same formula. The isomers can be
purified by techniques that are well known in the art. For example, optical isomers can
be separated by formation of diastereomeric addition salts with homochiral amines or
acids. Alternatively, optical isomers can be separated by chiral chromatography on
columns packed with chiral packing materials. Preferably, the isolated isomer is at least
about 80%, more preferably, at least 90% pure, even more preferably at least 98% pure,
most preferably at least about 99% pure, by weight. Preferably, the stereoisomer isolated
is the one possessing the more potent antiinflammatory activity.
The invention is also directed to a pharmaceutical composition of one or more
compounds of formula IX in combination with a pharmaceutically acceptable carrier.
According to another embodiment of the invention, a method for treating a
cyclooxygenase-mediated disease is provided, that includes the step of administering an
effective amount of a compound of the formula IX to an animal in need of such
treatment. The terms "animal", "subject" and "patient" include human beings.
In another embodiment of the invention, use of a compound of the formula IX for
the treatment of a patient having a cyclooxygenase-mediated disorder, such as
inflammation, an inflammation-mediated disorder, neoplasia or an angiogenesis-
mediated disorder, is provided.
In another embodiment, the invention relates to a use of a compound of the
formula IX in the manufacture of a medicament for treating a patient having
cyclooxygenase-mediated disorder, such as inflammation, an inflammation-mediated
disorder, neoplasia or an angiogenesis-mediated disorder.
The compounds of the formula IX are prepared by a process that includes the step
of contacting an oxime of the formula III

with an oxidizing agent and reacting the resulting nitrile oxide with an alkene of the
formula X

wherein Y, Z and R1 are as defined above.

In the processes and compounds of the invention, the aryl group Z includes
phenyl and heteroaryl, which may be substituted or unsubstituted. By "substituted" is
meant any level of substitution, although mono- di- and tri-substitution are preferred.
The substituents are independently selected. The substituents are preferably selected
from the group consisting of halogen, particularly chlorine, fluorine and bromine;
hydroxyl; amino; nitro; C1-C6 alkyl, preferably C1-C3 alkyl, most preferably methyl; C1-
C6 alkoxy, preferably C1-C3 alkoxy, most preferably methoxy; carboxy; C1-C6
trihaloalkyl, preferably trihalomethyl, most preferably trifluoromethyl; and cyano.
Although mono-, di- and tri-substitution is preferred, full substitution,
particularly when the aryl group is phenyl, is possible.
According to certain embodiments of the processes, Z is substituted or
unsubstituted heteroaryl. Such heteroaryl radicals include, for example, pyridyl,
particularly 2-, 3- and 4-pyridyl; thienyl, particularly 2- and 3-thienyl; furyl, particularly
2- and 3-furyl; indolyl, particularly 3-, 4-, 5-, 6- and 7-indolyl; benzothienyl, particularly
3-, 4-, 5-, 6- and 7-benzothienyl; benzofuryl, particularly 3-, 4-, 5-, 6- and 7-benzofuryl;
imidazolyl, particularly 2- and 5-imidazolyl; pyrazolyl, particularly 3- and 5-pyrazolyl;
2-thiazolyl; 2-benzothiazolyl; quinolinyl, particularly 2-, 3- and 4-quinolinyl; and 4-(2-
benzyloxazolyl). In some preferred embodiments, Z is 3-indolyl. Representative
preferred substituted heteroaryl groups include 6-methyl-2-pyridyl, 5-halo-2-thienyl, 5-
methyl-2-thienyl, 5-halo-2-furyl, 5-halo-3-furyl, 2,5-dimethyl-3-thienyl and 2,5-
dimethyl-3-furyl.
In other embodiments of the processes, Z is selected from the group consisting of
unsubstituted phenyl, mono-, di- and trisubstituted phenyl. Preferred radicals wherein Z
is substituted phenyl include, for example, one or more of amino, halogen, hydroxyl,
nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl and cyano.
In preferred embodiments of the processes, R1 is methyl, R2 is amino or n-
propionylamino, R5 is hydrogen and Z is phenyl.
In another aspect, the processes of the invention include preparations of the
alkyne of the formula IV

wherein R1 is hydrogen, trihalomethyl, C1-C6 alkyl and a group of the formula II.

In other embodiments, the processes of the invention include preparations of the
alkene of the formula X

wherein R1 is hydrogen, trihalomethyl, C1-C6 alkyl and a group of the formula II.
In other aspects, the invention relates to processes for preparing a compound of
the formula Ib

wherein R1 and R5 are as described above and R6 is C1-C5 alkyl, preferably C1-C3, more
preferably ethyl; and their corresponding alkali metal salts (formed from the
deprotonation of the alkanamide moieties).
In another aspect, the invention relates to a compound of the formula


wherein R1 is hydrogen, trihalomethyl, C1 to C6 lower alkyl or a group of the formula
II
wherein

R3 and R4 are independently selected from the group consisting of hydrogen,
amino, halogen, hydroxyl, nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6
trihaloalkyl, cyano, alkylsulfonyl, sulfamyl, phosphonato and hydroxyalkyl;
R2 is selected from the group consisting of amino, C1-C6 alkanoylamino or C1-C6
lower alkyl; and
R5 is selected from the group consisting of hydrogen, amino, halogen, hydroxyl,
nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl, cyano,
phosphonato, and hydroxyalkyl.
Brief Description of the Drawings
Figure 1 depicts some embodiments of the process for the preparation of the
compound of the formula I.
Figure 2 depicts some embodiments of the process for the preparation of the
compound of the formula IX.
Detailed Description of the Invention
The following terms shall have, for the purposes of this application, the
respective meanings set forth below.
"Alkanoylamino" includes linear and branched alkanoylamino groups, e.g., acetamido-,
propionylamido-, pivaloylamido-, and the like.
"Alkoxy" includes linear and branched alkoxy groups, e.g., methoxy, ethoxy, t-butyloxy,
and the like.
"Alkyl" includes linear and branched alkyl groups, e.g., methyl, ethyl, t-butyl, and the
like.
"Aryl" alone or in combination, includes carbocylic aromatic systems or a heterocyclic
aromatic systems (also known as heteroaryl). The systems may contain one, two
or three rings wherein such ring may be attached together in a pendent manner or
may be fused.
"Chlorophosphate reagent" includes dialkyl chlorophosphates (e.g., dimethyl and diethyl
chlorophosphates) and diaryl chlorophosphates (e.g., diphenyl chlorophosphate).
"Effective amount" will be recognized by clinicians but includes an amount effective to
reduce, ameliorate or eliminate one or more symptoms with any disorder

characterized by undesirable prostaglandin production resulting from
cyclooxygenase activity, particularly COX-2 activity ("cyclooxygenase-mediated
disorder").
"Inert organic solvent" means any organic solvent or combination of solvents that is
unreactive in the reaction being conducted, and is a solvent for the reactants.
Examples of such solvents used in the various reactions of this invention are
identified in the discussion of the reaction schemes and in the examples.
"Strong base" means a non aqueous base such as sodium-, potassium-, lithium
hexamethyldisilazide, lithium diisopropyl amide, and the like.
"Trialkylamine" includes triethylamine, N,N-dimethylethylamine, N,N-
diisopropylethylamine, and the like.
In accordance with the present invention, novel processes and synthetic
intermediates for the preparation of substituted isoxazoles of the formula I

are provided. In addition the invention provides substituted 2-isoxazolines of the
formula IX

and processes for their preparation. The 2-isoxazoline compounds of the formula IX are
structurally similar to the isoxazole compounds of the formula I as the isoxazoline
compounds are 4,5-dihydro analogs of the isoxazole compounds. In addition to their
structural similarity, their synthetic preparations share analogous reaction pathways and
certain common synthetic intermediates. The processes of the invention have been
developed from readily available and inexpensive starting materials. In addition, the
processes provide high yields of substituted isoxazoles and 2-isoxazolines.
Substituted Isoxazoles (Compound of the Formula I)
In one embodiment of the invention, the compound of the formula I

Kl
wherein R1, Y and Z are as described above in the summary.
The nitrile oxide is generally generated in situ from the oxime of the formula III
by oxidation with a suitable oxidizing agent, e.g. N-chloro-p-toluenesulfonamide,
sodium salt; alkaline sodium hypochlorite; chlorine; N-bromosuccinimide; lead
tetraacetate, in an alcohol solvent, e.g., methanol. The nitrile oxide (isolated after water
workup) is added directly to the alkyne of the formula IV in an alcohol solvent, e.g.,
ethanol, and the reaction mixture is heated to about 70 °C to about 80 °C for about 30
minutes to about 6 h, preferably about 3 h to give the desired isoxazole. Preferably,
equimolar amounts of the nitrile oxide and the alkyne of the formula IV are used. After
water workup the organic layer is concentrated to isolate the crude substituted isoxazole
of the formula I. The compound of the formula I can be further purified by
recrystallization in suitable solvents such as ethanol.
In certain embodiments, particularly wherein R1 is a group of the formula II
(phenyl or substituted phenyl) in the alkyne of the formula III, the cycloaddition step
may result in mixtures of regioisomers. As will be apparent to those of ordinary skill in
the art, these mixture can be separated by well-known separation techniques, e.g.,
chromatography, recrystallization, and the like, to obtain the desired regioisomer.
Various acid addition salts of the compound of the formula I can be prepared by
treatment with an organic or inorganic acid. Preferably, the acid addition salts formed
are pharmaceutically acceptable salts, such as those described in United States Patent No.
5,563,165, the disclosure of which is herein incorporated by reference. Suitable base
addition salts of the compound of formula I, wherein the phenyl group at the 5-position
of the pyrazole ring incorporates a carboxy or hydroxyl substituent. Base addition salts

include metallic addition salts, e.g., sodium, potassium, and organic base addition salts,
e.g, organic amines. Other pharmaceutically acceptable acid addition salts are detailed in
United States Patent No. 5,563,165.
Preparation of Alkvnes of the Formula IV. wherein R1 is Cj-C$ Alkyl or Hydrogen
In embodiments of the invention where R1 is C1-C6 alkylj, the alkyne of the
formula IV

can be obtained by deprotonation of a methyl ketone of the formula V

wherein Y is as described above, with a strong base, e.g., lithium diisopropylamide, in an
anhydrous ethereal solvent, e.g. tetrahydrofuran, at a temperature below 5 °C, preferably
about 0 °C. Typically, a slight molar excess of the strong base is used in the
deprotonation step, preferably about 5 to 10% molar excess. The deprotonation is
carried out for a period of about 15 to 45 minutes, preferably about 30 minutes. A
chlorophosphate reagent, preferably diethyl chlorophosphate, is subsequently added to
the reaction mixture to form a phosphonate intermediate that is typically not isolated.
The solution containing the phosphonate intermediate is then treated with at least two
molar equivalents of strong base, e.g., lithium diisopropylamide, at a temperature of
about -10 °C to about 10 °C, preferably about 0 °C. An alkylating agent of the formula
VI
R1-Q (VI)
wherein Q is a leaving group, e.g., halide, mesylate, tosylate and the like, can be added to
the reaction mixture, and the resulting mixture is heated to provide the alkyne of formula
IV. A cosolvent such as hexamethylphosphoramide (HMPA) can be added to the
reaction mixture to enhance the efficiency of the alkyne formation. The alkyne of the
formula IV is typically used directly in the [3+2] cycloaddition step without isolation. In
preferred embodiments, wherein R1 is methyl, methyl iodide is a preferred alkylating
agent.

In embodiments of the process wherein Y is phenyl substituted by a group of the
formula—SO2R2, wherein R2 is C1-C6 alkyl, the methyl ketones of the formula V can be
prepared by methods well known to those of ordinary skill in the art. For example,
acetophenone can be reacted with alkyl sulfonyl halides e.g., CH3SO2F, in Friedel-Craft
type reactions. Alternatively, methyl ketones containing alkyl sulfonyl substituents can
be prepared by oxidation of phenyl alkyl thioethers.
In other preferred embodiments of the process, wherein Y is phenyl substituted
by a group of the formula—SO2R2, wherein R2 is amino, the methyl ketones of the
formula V can be prepared by treating the acetophenone of the formula XV, with
ammonium hydroxide at room temperature as depicted in the preparation of 4-
sulfamylacetophenone (Va) in Scheme 1. The sulfonamido moiety can be acylated with
an acylating agent of the formula XIX, wherein R6 is C1-C5 alkyl, preferably C1-C3 alkyl,
in the presence of a trialkylamine base, e.g. triethylamine, to give the compound of the
formula XXI, wherein R6 is C1-C5 alkyl.
Scheme 1

Preparation of Alkynes of the Formula IV. wherein R1 is Trifluoromethyl
The alkyne of the formula IV wherein R1 is trifluoromethyl can be prepared from
a substituted phenyl acetylene of the formula VII

wherein Y is as described above, by forming the corresponding acetylide using a strong
base, e.g., n-butyl lithium, in an ethereal solvent, e.g., tetrahydrofuran, and then
alkylating the acetylide with a trifluoromethyl alkylating reagent such as S-
(trifluoromethyl)phenyl-4-fluorophenyl-3-nitrophenylsulfonium triflate (prepared as
described in Yang et. al. J. Org. Chem. 1998, 63,2656) to give the alkyne of the formula
IVb


The reaction is typically conducted at temperatures of -80 °C to 25 °C, preferably about -
-78 °C for about 2 to about 5 hours.
Preparation of Alkynes of the Formula IV Wherein R1 is a Group of the Formula II

wherein R3 and R4 are as described above, can be obtained by the method depicted in
Scheme 2. An alkene of the formula Xb (obtained by the method described below) is
first treated with bromine in a suitable inert organic solvent, e.g., chloroform, at room
temperature for a sufficient amount of time to form a dibromo intermediate at about
room temperature. The dibromo intermediate is subsequently treated with a base, such
as an alkali metal hydroxide, e.g., potassium, sodium, or lithium hydroxide, in an alcohol
solvent, e.g., ethanol, at temperatures of about 60 to about 100 °C to effect elimination of
HBr and provide the alkyne of formula IVa. The alkyne of the formula IVa can be
further purified by, for example, by recrystallization from suitable solvents, e.g.,
alcohols, when the compound is a solid. Alternatively, the compound of the formula IVa
can be purified by techniques such as chromatography or distillation (in the case of
liquids).
In an alternative procedure, the alkyne of the formula IV, wherein R1 is a group
of the formula II can be obtained by treating a substituted phenyl acetylene of the
formula VII

Ul

wherein Y is as described above, with a copper (II) salt, and reacting the resulting copper
acetylide with a compound of the formula VIII

wherein Q' is chloro, bromo or iodo, preferably iodo. Typically, the corresponding
copper acetylide of the substituted phenyl acetylene of the formula VII is generated by
reaction with the copper II salt, e.g., copper sulfate in the presence of aqueous ammonia
and hydroxylamine.
Substituted 2-Isoxazolines (Compound of the Formula IX)
The invention also relates to compounds of the formula IX

wherein R1, Y and Z are as described above in the summary section.
The compounds of the formula IX preferably are characterized by a selectivity
ratio for COX-2 inhibition over cyclooxygenase-1 (COX-1) inhibition of at least about
50, more preferably at least about 100. COX inhibition may be determined in vitro by
enzyme assays well-known to those skilled in the art, such as the enzyme assay method
described later herein.
The compounds of the present invention may take the form of pharmaceutically
acceptable salts. The term "pharmaceutically acceptable salts", embraces salts
commonly used to form alkali metal salts and to form addition salts of free acids or free
bases. Where reference is made to "compound of formula IX (including IXb)", it is
understood that pharmaceutically acceptable salts are also included. The nature of the
salt is not critical, provided that it is pharmaceutically-acceptable. Suitable
pharmaceutically acceptable acid addition salts may be prepared from an inorganic acid
or from an organic acid. Examples of such inorganic acids are hydrochloric,
hydrobromic, hydroiodic, nitric, carbonic, sulfuric and phosphoric acid. Appropriate
organic acids may be selected from aliphatic, cycloaliphatic, aromatic, araliphatic,

heterocyclic, carboxylic and sulfonic classes of organic acids, exjample of which are
formic, acetic, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric,
ascorbic, glucuronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic,
mesylic, salicyclic, 4-hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic),
methanesulfonic, ethanesulfonic, benzenesulfonic, pantothenic, 2-
hydroxyethanesulfonic, toluenesulfonic, sulfanilic, cyclohexylaminosulfonic, stearic,
algenic, beta- hydroxybutyric, galactaric and galacturonic acid. Suitable
pharmaceutically acceptable base addition salts of compounds of formula IX (including
IXb) include metallic salts made from calcium, lithium, magnesium, potassium, sodium
and zinc or organic salts made from N,N'-dibenzylethylenediamine, chloroprocaine,
choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and
procaine. All of these salts can be prepared by conventional means from the
corresponding compound of formula IX by reacting, for example, the appropriate acid or
base with the compound of formula IX.
The compounds of the formula IX may be administered in the form of a
pharmaceutical composition, in combination with a pharmaceutically acceptable carrier.
The active ingredient in such formulations can comprise from 0.1 to 99.99 weight
percent. By "pharmaceutically acceptable carrier" is meant any carrier, diluent or
excipient which is compatible with the other ingredients of the formulation and is not
) deleterious to the recipient.
The compounds of the formula IX may be administered to individuals (animals,
most particularly mammals including humans) afflicted with any disorder characterized
by undesirable prostaglandin production resulting from cyclooxygenase activity,
particularly COX-2 activity ("cyclooxygenase-mediated disorder"). In particular, the
compounds of the formula IX are believed useful in treating inflammation and
inflammation-related disorders, by administering to a subject having or susceptible to
i
such inflammation or inflammation-related disorder an effective amount of a compound
according to formula IX. Inflammation is associated with a variety of disease conditions.
For a list of such disease conditions treatable by cyclooxygenase inhibitors, and COX-2
inhibitors in particular, see United States Patent Nos. 5,604,253 and 5,908,852, the entire
disclosures of which are incorporated herein by reference. Such conditions include, for
example, arthritis, including but not limited to rheumatoid arthritis,
spondyloarthropathies, gouty arthritis, osteoarthritis, systemic lupus erythematosus and

juvenile arthritis. Such conditions further include rheumatic fever, symptoms associated
with influenza or other viral infections, common cold, lower back and neck pain,
dysmenorrhea, headache, toothache, sprains and strains, myositis, neuralgia, synovitis,
gout and ankylosing spondylitis, bursitis, and following surgical and dental procedures.
The compounds of the formula IX are believed useful as analgesics for treating or
alleviating all forms of pain. The compounds are believed useful in the treatment of
other disorders including asthma, bronchitis, tendinitis, bursitis; skin related conditions
such as psoriasis, eczema, bums and dermatitis; gastrointestinal conditions such as
inflammatory bowel disease, Crohn's disease, gastritis, irritable bowel syndrome and
ulcerative colitis and for the prevention of colorectal cancer; the treatment of
inflammation in such diseases as vascular diseases, migraine headaches, periarteritis
nodosa, thyroiditis, aplastic anemia, Hodgkin's disease, sclerodoma, type I diabetes,
myasthenia gravis, sarcoidosis, nephrotic syndrome, Behcet's syndrome, polymyositis,
gingivitis, hypersensitivity, conjunctivitis, swelling occurring after injury, myocardial
ischemia, and the like. The compounds of the formula DC are believed useful as
antipyretics for the treatment of fever.
In addition, compounds of the formula IX may be useful in the treatment of
Alzheimer's disease and mild cognitive impairment.
In addition, compounds of the formula IX may inhibit cellular neoplastic
transformations and metastatic tumor growth and hence can be used in the treatment of
cancer. In particular, the present invention provides a method for treating or preventing a
neoplasia that produces a prostaglandin in a subject in need of such treatment or
prevention, the method includes treating the subject with a therapeutically effective
amount of a compound of formula IX. The term "neoplasia" includes neoplasias that
produce prostaglandins or express a cyclooxygenase, including both benign and
cancerous tumors, growths and polyps. Neoplasias believed treatable with
cyclooxygenase inhibitors are discussed in United States Patent No. 5,972,986, the entire
disclosure of which is incorporated herein by reference. The compounds may be used to
inhibit the growth of an established neoplasm, i.e., to induce regression, or to prevent or
delay the onset of the neoplasm.
According to United States Patent No. 5,972,986, neoplasias that produce
prostaglandins, and which are therefore believed treatable with the compounds of the
invention, include brain cancer, bone cancer, epithelial cell-derived neoplasia (epithelial

carcinoma) such as basal cell carcinoma, adenocarcinoma, gastrointestinal cancer such as
lip cancer, mouth cancer, esophageal cancer, small bowel cancer and stomach cancer,
colon cancer, liver cancer, bladder cancer, pancreatic cancer, ovarian cancer, cervical
cancer, lung cancer, breast cancer and skin cancer, such as squamous cell and basal cell
cancers, prostate cancer, renal cell carcinoma, and other known cancers that effect
epithelial cells throughout the body.
The compounds of the formula IX may also be useful in the treatment of
angiogenesis-mediated disorders. Thus, a method for treating, inhibiting or delaying the
onset of an angiogenesis-mediated disorder in a subject is provided comprising
administering to a subject in need of such treatment an effective amount of a compound
according to the present invention. Angiogenesis-mediated disorders which may be
treatable with cyclooxygenase inhibitors are discussed in United States Patent No.
6,025,353, the entire disclosure of which is incorporated herein by reference. According
to United States Patent No. 6,025,353, such disorders include, for example, metastasis,
corneal graft rejection, ocular neovascularization, retinal neovascularization, diabetic
retinopathy, retrolental fibroplasia, neovascular glaucoma, gastric ulcer, infantile
hemaginomas, angiofibroma of the nasopharynx, avascular necrosis of bone, and
endometriosis.
The compounds may be administered by any route, including oral and parenteral
administration. Parenteral administration includes, for example, intravenous,
intramuscular, intraarterial, intraperitoneal, intranasal, rectal, or subcutaneous
administration. The active agent is preferably administered with a pharmaceutically
acceptable carrier selected on the basis of the selected route of administration and
standard pharmaceutical practice.
The active agent may be formulated into dosage forms according to standard
practices in the field of pharmaceutical preparations. See Alphonso Gennaro, ed.,
Remington's Pharmaceutical Sciences, 18th Ed., (1990) Mack Publishing Co., Easton,
PA. Suitable dosage forms may include, for example, tablets, capsules, solutions,
parenteral solutions, troches, suppositories, or suspensions.
For parenteral administration, the active agent may be mixed with a suitable
carrier or diluent such as water, an oil, saline solution, aqueous dextrose (glucose) and
related sugar solutions, or a glycol such as propylene glycol or polyethylene glycol.
Solutions for parenteral administration preferably contain a water soluble salt of the

active agent. Stabilizing agents, antioxidizing agents and preservatives may also be
added. Suitable antioxidizing agents include sulfite, ascorbic acid, citric acid and its
salts, and sodium EDTA. Suitable preservatives include benzalkonium chloride, methyl-
or propyl-paraben, and chlorbutanol.
For oral administration, the active agent may be combined with one or more solid
inactive ingredients for the preparation of tablets, capsules, or other suitable oral dosage
forms. For example, the active agent may be combined with carboxymethylcellulose
calcium, magnesium stearate, mannitol and starch, and then formed into tablets by
conventional tableting methods.
The specific dose of compound according to the invention to obtain therapeutic
benefit will, of course, be determined by the particular circumstances of the individual
patient including, the size, weight, age and sex of the patient, the nature and stage of the
disease, the aggressiveness of the disease, and the route of administration. For example,
a daily dosage of from about 0.01 to about 150 mg/kg/day may be utilized. Higher or
lower doses are also contemplated.
The compounds of the formula IX contain two chiral carbon atoms at positions 4
and 5 of the isoxazoline nucleus. The present invention is meant to comprehend all
stereoisomers of the compound of the formula IX including isolated optical isomers,
isolated diastereoisomers and mixtures thereof (including pharmaceutically acceptable
salts thereof). In addition, other chiral carbon atoms may also be present in the
i
compound.
Diastereoisomers can be isolated by well-known techniques including
chromatography and recrystallization techniques. Isolated optical isomers may be
purified from racemic mixtures by well-known chiral separation techniques. According
to one such method, a racemic mixture of a compound having the structure of formula IX
or chiral intermediate thereof, is separated into 99% wt.% pure optical isomers by HPLC
using a suitable chiral column, such as a column containing a packing of chiral phase
material bonded to silica gel.
The compound of the formula IX


wherein R1, Y and Z are as described above in the summary section, can be obtained by a
[3+2] cycloaddition of a nitrile oxide obtained from the oxidation of the oxime of the
formula III
and an alkene of the formula X
The nitrile oxide is generated from the oxime as described above in the synthesis of the
isoxazole compound of the formula I. The nitrile oxide is typically mixed with the
alkene of the formula X in an alcohol solvent, e.g., ethanol, and the resulting mixture is
heated to about 50 °C to about 100 °C for about 30 minutes to about 6 hours, preferably
about 3 hours to give the desired substituted-2-isoxazoline. Preferably, equimolar
amounts of the nitrile oxide and the alkene of the formula X are used. After water
workup, the organic layer is concentrated to isolate the compound of the formula IX.
The compound of the formula IX can be further purified by recrystallization in suitable
solvents such as methanol.
In certain embodiments, particularly wherein R1 is a group of the formula II
(substituted or unsubstituted phenyl) in the alkene of the formula X, the cycloaddition
step may result in mixtures of regioisomers. As will be apparent to those of ordinary
skill in the art, these mixtures can be separated by well-known separation techniques,
e.g, chromatography, recrystallization, and the like, to obtain the desired regioisomer.
Various acid addition salts of the compound of the formula IX can be prepared by
treatment with an organic or inorganic acid. Preferably, the acid addition salts formed
are pharmaceutically acceptable salts, such as those described in United States Patent No.
5,563,165, the disclosure of which is herein incorporated by reference. Suitable base
addition salts of the compound of formula I, wherein the phenyl group at the 5-position
of the pyrazole ring incorporates a carboxy or hydroxyl substituent. Base addition salts
include metallic addition salts, e.g, sodium, potassium, and organic base addition salts,
e.g, organic amines. Other pharmaceutically acceptable acid addition salts are detailed in
United States Patent No. 5,563,165.

Preparation of Alkenes of the Formula X (General Methods)
The alkene of the formula X

wherein R1 is hydrogen, C1-C6 alkyl, trihalomethyl or a group of the formula II can be
prepared by a number of processes known in the art. For example, a Wittig reaction can
be conducted with a substituted phenyl aldehyde of the formula XI
Y-CHO PQ),
wherein Y is as described above, and a compound of the formula XIII
Ph3P-CHR1 (XIII)
to give the alkene of the formula X. The compound of the formula XIII can be generated
from the corresponding phosphonium salt
Ph3P-CH2R1 + I- (or Br-)
by reaction with a strong base, e.g., n-butyllithium, in a suitable organic solvent, e.g.,
diethyl ether. The phosphonium salts, in turn, are either readily commercially available
(e.g., Aldrich Chemical Co., Milwaukee, WI), or can be generated from the
corresponding alkyl iodides or bromides by reaction with triphenylphosphine.
i
Preparation of Alkenes of the Formula X (wherein R1 is C1-C6 alkyl)
In addition to Wittig-type condensations, additional procedures are also useful for
the preparation of certain alkenes of the formula X, wherein R1 is C1-C6 alkyl. For
example, a Knoevenagel-type condensation of an aldehyde of the formula XI
Y-CHO (XI)
with nitromethane yields a nitroalkene of the formula XII

(as described in Liu et al. (Tetrahedron Lett. 2001, 42, 6147-6150). Typically, the
condensation is conducted in acetic acid with added ammonium acetate at between about
75-118 °C from about 3 hours to about 24 hours. The resulting nitroalkene is then
treated with at least 3 molar equivalents of triethylborane (preferably about 4
equivalents) to give the alkene of the formula X wherein R1 is ethyl. To prepare alkenes
of the formula X, wherein R1 is other than ethyl, the corresponding alkyl iodide (i.e., R1-

1,6-20 equivalents) can be added to the reaction mixture in addition to triethylborane.
The reaction of the nitroalkene with triethylborane or triethylborane / alkyl iodide is
conveniently conducted, for example, as a one-pot process by addition of diethyl ether
and water to the Knoevenagel condensation reaction mixture. Alternatively, the
intermediate nitroalkene can be isolated, and then subjected to the alkylation procedure
in an ethereal solvent, e.g. tetrahydrofuran, at about room temperature (Liu et al. J. Org.
Chem. 2001, 42, 6147-6150).
Preparation of Alkenes of the Formula X (wherein R1 is a Group of the Formula II)
In another embodiment, a procedure for preparing an alkene of the formula X,
wherein R1 is a group of the formula II

is provided. In the procedure a substituted phenyl aldehyde of the formula XI
Y-CHO (XI),
wherein Y is as described above, is condensed with a substituted or unsubstituted phenyl
acetic acid of the formula XVII

In one typical procedure, the condensation reaction is conducted using a base, e.g.,
piperidine, without added solvent. Alternatively, the condensation can be conducted in
acetic anhydride using triethylamine. The reaction temperatures for the condensations
are about 120 °C to about 140 °C from about 8 to about 12 hours.
Preparation of Alkenes of the Formula X (wherein R1 is Trifluoromethyl)

Another procedure provides a method for preparing an alkene of the formula X,
wherein R1 is trifluoromethyl. In this procedure, an alkyne of the formula VII

is treated with iodine (about 1 to 1.8 equivalents) to form a diiodo alkene of the formula

The diiodo compound of the formula XIV is then reacted with a slight molar
excess of a reagent of the formula
FSO2CF2CO2CH3
in the presence of a catalytic amount of copper iodide in a suitable organic solvent, e.g.,
dimethylformamide, at 60 to about 100 °C, preferably about 75 to 80 °C to give an iodo-
trifluoromethyl substituted alkene intermediate XVI
1
1
The trifluoromethylating reagent can be prepared according to procedures described in
Wiamers et al. J. Am. Chem. Soc. 1986,108, 832. The intermediate XVI can then be
reduced using, for example, about 3 to about 4 equivalents of zinc, a catalytic amount of
silver acetate and acetic acid in dimethylformamide at 15 to about 35 °C for about 1 to
about 24 hours. After water workup, the alkene of the formula Xa

is isolated, for example, by distillation or chromatography. This procedure is
exemplified in Duan et al., J. Org. Chem. 1998, 63, 9486-9489.
Alternatively, an alkene of the formula Xa can be obtained through controlled
catalytic hydrogenation of the alkyne of the formula IVb (prepared as described above)

using, for example, a selective hydrogenation catalyst, e.g., Lindlar's catalyst, a nickel-
boride catalyst, to give the alkene in a suitable inert organic solvent, e.g, ethanol.

Preparation of N-[[5-Substituted-3-phenvlisoxal-4-yl)phenyl]sulfonvl]alkanamide and
N-[[5-Substituted-3-phenvl-2-isoxalin-4-yl]phenyl]sultbnyl]alkanamides and their Salts
(Compounds of the Formula Ib. Ib'. IXb and IXb'
In another aspect the invention relates to a method of preparing a compound of
the formula Ib
wherein R1 and R5 are as described above and R6 is C1-C5 alkyl, and their corresponding
base addition salts (formed from the deprotonation of the alkanamide moieties). The
process for preparing for the compounds includes the step of preparing the compounds of
the formulas la and IXa using the [3+2] cycloaddition process described above for the
preparation of the compounds of the formula I and IX. The preparation of the isoxazole
compound of the formula Ib and its corresponding base addition salt is shown in Scheme
3. Preferred base addition salts include alkali metal salts (wherein M+ is an alkali metal
cation selected from sodium, potassium and lithium, preferably sodium in Scheme 3)


After the cycloaddition step, the sulfonamide moiety of the compound of the formula la
is acylated with an acylating agent of the formula XIX, wherein R6 is C1-C5 alkyl,
preferably C1-C3 alkyl, in the presence of a trialkylamine base, e.g. triethylamine, to give
the compound of the formula Ib. It will be apparent to those of skill in the art that
alternative acylating reagents can be used for the acylation including acid chlorides,
activated esters, and the like. The corresponding alkali metal salt Ib' can be prepared by
treatment of the compound of the formula Ib with an alkali metal base, e.g., an alkali
metal hydroxide of the formula
M+ OH-,
wherein M+ is an alkali metal cation, preferably sodium cation. Typically the base
treatment is performed using aqueous hydroxide solution.
Alternatively, the compound of the formula Ib can be prepared by preparing an
alkyne of the formula IVd,


having a sulfonamido moiety already in place, and treating the alkyne with a nitrile oxide
in a [3+2] cycloaddition as described above.
The isoxazoline compound of the formula IXb and its corresponding basic
addition salt can be formed using an analogous synthetic route as depicted in Scheme 4.
Scheme 4
E A
Alternatively, the compound of the formula IXb can be prepared by preparing an
alkene of the formula Xd,
i
having a sulfonamido moiety already in place, and treating the alkene with a nitrile oxide
in a [3+2] cycloaddition as described above.
In embodiments of the above processes wherein the substituted or unsubstituted
i phenyl group Y, the aryl group Z, or a group of the formula II


bear substituents such as hydroxyl or carboxy that may interfere or decrease the yield of
certain synthetic steps, suitable protecting groups for these substituents that are well
known in the art, can be used. The protecting groups can be then removed at appropriate
points in the synthetic sequence by known methods. Thus, for example, a hydroxyl
moiety can be protected as a methyl or silyl ether. Similarly, a carboxy moiety can be
protected as an ester if necessary, which can be hydrolyzed in a later synthetic step.
The following examples further illustrate the present invention, but of course,
should not be construed as in any way limiting its scope.
Example 1 - Preparation of 3-(4-ChlorophenylV4-Phenyl Isoxazole (Compound of the
Formula I wherein R1=H. Y=4-phenvl and Z=4-chlorophenvl).

A solution of phenylacetylene (10 mmol), 4-chlorobenzaldoxime (10 mmol) and
chloramine-T (10 mmol, N-chloro-p-toluenesulfoneamide, sodium salt) were dissolved
in methanol (40 mL) and refluxed for 6 h. The contents of the flask were cooled and the
precipitated material, which was a mixture of isoxazole and 4 -toluenesulfonamide, was
filtered and washed with water. The solid material on boiling in hot water kept the
sulfonamide in solution while precipitating the isoxazole. The precipitated isoxazole
was filtered and recrystallized from ethanol, yield (82%), m.p.: 178-180 °C; 1H NMR
(DMSO-d6) 6.75(s, 1H), 7.49-7.55(m, 5H), 7.77-7.82 (m, 4H).
Example 2 - Preparation of 4-[5-methvl-3-phenvl-isoxazol-l-vl1benzenesulfonamide
(Compound of the Formula I wherein R1=CH3,Y=4-sulfamvlphenyl and Z=phenyl).


Preparation of 4-sulfamyl acetophenone (Va):

To a solution of 4-acetylbenzene sulfonyl chloride (XV, 10 mmol) in ether (120
mL), ammonium hydroxide (4 mL) is added. After stirring at room temperature for 5 h,
the solvent is removed, and the residue is stirred with 3 N HC1 (100 mL) for 1 h and
filtered. The solid obtained is washed with water, ether, and then dried under reduced
pressure. The 4-sulfamyl acetophenone obtained is used in the next step without further
purification.
Preparation of l-(4-sulfamvlphenyl)-1-Propvne (Alkvne of the Formula IV. wherein Y is
4-sulfamylphenyl and R1 is methyl. R2=NH2):

A solution of lithium diisopropylamide (5.25 mmol) in THF is charged to a dry
two-necked flask flushed with nitrogen maintained at 0 °C. To this solution, 4-
sulfamylacetophenone (Va, 5 mmol) is added dropwise to the stirred solution with
constant bubbling of the solution with dry nitrogen. The reaction mixture is stirred for
30 min at 0 °C, followed by the addition of diethyl chlorophosphate (5.75 mmol).
A cooled solution of lithium diisopropylamide (12.5 mmol) is added to the stirred
reaction mixture via syringe. To this reaction mixture 3 mL of
hexamethylphosphoramide (HMPA) is added, and the reaction mixture is warmed to 5
°C followed by the addition of 2.5 mL (37.5 mmol) of iodomethane. At this point, the
nitrogen inlet tube is replaced with a reflux condenser. The reaction mixture is refluxed
for 1 h, followed by the addition of 10 mL of saturated ammonium chloride solution.
After 5 minutes of stirring, 20 mL of ether is added. The mixture is shaken, and the ether
layer is separated and evaporated to give l-(4-sulfamylphenyl)-l-propyne.

Preparation of 4-f5-methyl-3-phenyl-isoxazol-l-yl]benzenesulfonamide:
A solution of benzaldehyde oxime (5 mmol) in methanol (15 mL) is heated to
30-40 °C. Chloramine-T (5 mmol) is then added and the contents are heated to reflux.
The solvent is removed in vacuo and the residue obtained is extracted with
dichloromethane (100 mL), washed with 1 M NaOH, brine and then dried. Removal of
the dichloromethane under reduced pressure yields the nitrile oxide. The nitrile oxide (5
i
mmol) is added to l-(4-sulfamylphenyl)-l-propyne (5 mmol) in ethanol (50 mL) and the
resulting mixture is refluxed for 3 h. The cooled reaction mixture is filtered, washed
with brine and water. Concentration under reduced pressure gives 4-[5-methyl-3-phenyl-
isoxazol-1 -yl]benzenesulfonamide.
Example 3: Preparation of -Trifluoromethvl-phenvlacetvlene (A'kyne of the Formula
IV wherein R1 is Trifluoromethyl and Y is Phenyl)

A solution of phenylacetylene (10 mmol) in tetrahydrofuran (30 ml) is cooled to -
72 °C and n-butyl lithium in tetrahydrofuran (1 mmol) is added. To this solution is
added a solution of S-(trifluoromethyl)phenyl-4-fluorophenyl-3-nitrophenylsulfonium
triflate (12 mmol) in THF (10 ml). The resulting mixture is stirred under a nitrogen
atmosphere for 5 h. The solvent is removed under reduced pressure and the product is
purified by column chromatography.
Example 4 - Preparation of 2-Isoxazolines (Compounds of the Formula IX).

(5 mmol) in methanol (15 ml) is heated to 30-40 °C. Chloramine-T (1.45 g, 5 mmol) is
then added, and the contents are heated to reflux. The solvent is removed in vacuo and
the residue obtained is extracted with dichloromethane (100 mL), washed with 1M

NaOH, brine and then dried. Removal of the solvent under reduced pressure yields the
nitrile oxide. The nitrile oxide (5 mmol) is added to the alkene of the formula X

(5 mmol) in ethanol (50 ml), and the resulting mixture is refluxed for 3 h. Diethyl ether
is added to the cooled reaction mixture. The resulting mixture is washed with brine and
water. Concentration under reduced pressure gives the compound of the formula IX.
The product can be further purified by recrystallization from suitable recrystallization
solvents, e.g., methanol.
Example 5: Cvclooxvgenase Inhibitory Assay
Cyclooxygenase activity of ovine COX-1 (Oxford Biomedical Research Inc.) and
human recombinant COX-2 (Oxford Biomedical Research Inc.) are assayed by a thin
layer chromatography (TLC) method as follows. All inhibitors are dissolved in dimethyl
sulfoxide to a stock solution of 5mM. Human recombinant COX-2 (3 units) or ovine
COX-1 (15 units) is incubated with inhibitors at several concentrations in a solution
containing 100 mM Tris-HCI, pH 7.8, 500 uM phenol and hematin for 90 to 120 minutes
at room temperature (24°C). In controls, equal volumes of DMSO without drug are
added to the incubation mixture. After incubation for 90-120 minutes, [1-14C]
arachidonic acid (50uM, 51mCi/mmol) (DuPont NEN) is added and incubated at 37 °C
for 2 minutes. The reaction is terminated by extraction with 1 mL of ethyl acetate. The
ethyl acetate layer is transferred into a fresh tube and evaporated to dryness in a vacuum
dryer. The contents of the tubes are reconstituted in 20 mL of ethyl acetate, spotted on a
TLC plate (J.T. Baker, Phillipsburg, NJ) and developed in a mobile phase containing
chloroform/methanol (95:5) at 4°C. Radiolabeled prostanoid compounds (the products
of COX enzymatic reaction with radiolabeled arachidonic acid substrate) are quantitated
with a radioactivity scanner (Fuji, Phosphorimager). The percentage of total products
observed at different inhibitor concentrations is divided by the percentage of the products
observed for protein samples pre incubated for the same time with DMSO.

Example 6: Soft Agar Assay
Compounds of the formula IX are assayed for inhibition of growth of DLD-1
cells in soft agar. DLD1 cells are human colorectal carcinoma cells that overexpress
COX-2. DLD-1 cells grow in soft agar and form tumors in nude mice. The soft agar
assay is performed as follows. A layer of bottom agar (8% noble agar) is placed onto 60
mm2 tissue culture dishes. The tumor cells are trypsinized from normal growth flasks
while in exponential growth. The cells are counted by using a hemacytometer and 1.0 x
105 cells are placed into the top agar mixture containing growth medium, 4% noble agar
and various concentrations of drugs. The concentration range is normally between 10
M to 75 M. The cells are not refed during the assay system; therefore, the cells are
treated with one dose of the agents. The plates are stained 20 days later with a 0.05%
(w/v) nitroblue tetrazolium solution (which stains only viable cells) for 48 hours. A
comparison of the percent of cell colonies remaining in the drug treated cells is made
relative to the untreated cells.
While this invention has been described with an emphasis upon preferred
embodiments, it will be obvious to those of ordinary skill in the art that variations in the
preferred devices and methods may be used and that it is intended that the invention may
be practiced otherwise than as specifically described herein. Accordingly, this invention
includes all modifications encompassed within the spirit and scope of the invention as
defined by the claims that follow.

We claim:
1. A process for the preparation of a compound of the formula

wherein R1 is selected from the group consisting of hydrogen, trihalomethyl, C1-C6 alkyl
and
a group of the formula IT
wherein
R3 and R4 are independently selected from the group consisting of hydrogen, amino,
halogen, hydroxyl, nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl,
cyano, alkylsulfonyl, sulfamyl, phosphonato and hydroxyalkyl;
Y is a group of the formula
wherein
R2 is selected from the group consisting of C1-C6alkyl, C1-C6alkanoylamino and
amino;
and
R5 is selected from the group consisting of hydrogen, amino, halogen, hydroxyl, nitro,
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl, cyano, phosphonato, and
hydroxyalkyl; and
Z is selected from the group consisting of optionally substituted heteroaryl selected from the
group consisting of optionally substituted indolyl, furyl, thienyl, pyridyl, benzofuryl,
benzothienyl, imidazolyl, pyrazolyl, thiazolyl, benzothiazolyl, quinolinyl, and

4-(2-benzyloxazolyl) and phenyl substituted with one or more of amino, halogen, hydroxyl,
nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl and cyano;
the process comprising: contacting an oxime of the formula III

with an oxidizing agent and reacting the resulting nitrile oxide with an alkyne of the
formula IV

2. The process as claimed in claim 1, wherein R1 is methyl, R2 is amino or n-
propionylamino and R5 is hydrogen.
3. A process for the preparation of a compound of the formula Ib'

wherein R1 is selected from the group consisting of hydrogen, trihalomethyl, C1-C6 alkyl and
a group of the formula II
wherein
R3 and R4 are independently selected from the group consisting of hydrogen, amino,
halogen, hydroxyl, nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl,
cyano, alkylsulfonyl, sulfamyl, phosphonato and hydroxyalkyl;
R5 is selected from the group consisting of hydrogen, amino, halogen, hydroxyl, nitro, C1-C6
alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl, cyano, phosphonato, and hydroxyalkyl;
R6 is C1-C5 alkyl;

Z is selected from the group consisting of optionally substituted heteroaryl selected from the
group consisting of optionally substituted indolyl, furyl, thienyl, pyridyl, benzofuryl,
benzothienyl, imidazolyl, pyrazolyl, thiazolyl, benzothiazolyl, quinolinyl, and 4-(2-
benzyloxazolyl) and phenyl substituted with one or more of amino, halogen, hydroxyl, nitro,
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl and cyano; and
M is an alkali metal;
the process comprising:
(a) reacting an oxime of the formula III

with an oxidizing agent selected from the group consisting of N-chloro-p-
toluenesulfonamide, sodium salt, alkaline sodium hypochlorite; chlorine; N-
bromosuccinimide and lead tetraacetate;
(b) reacting the resulting nitrile oxide with an alkyne of the formula IVc

by adding the nitrile oxide to the alkyne of the formula IVc in an alcohol solvent to form a
reaction mixture;
(c) heating the reaction mixture to about 70 °C to about 80 °C for about 30 mintues to
about six hours to provide a compound of the formula


(d) acylating the compound of the formula Ia with an acylating agent of the formula
XIX

(e) reacting the compound of the formula Ib with a alkali metal base such as an alkali
metal hydroxide, to give the compound of the formula Ib'
4. The process as claimed in claim 3, wherein R1 is methyl, R5 is hydrogen, R6 is ethyl, Z
is phenyl and M is sodium.
5. A compound of the formula IX

wherein R1 is selected from the group consisting of hydrogen, trihalomethyl, C1-C6 alkyl, and
a group of the formula II
wherein
R3 and R4 are independently selected from the group consisting of hydrogen,
amino,

halogen,, hydroxyl, nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6
trihaloalkyl,
cyano, alkylsulfonyl, sulfamyl, phosphonato and hydroxyalkyl;
Y is a group of the formula

wherein
R2 is selected from the group consisting of C1-C6 alkyl, C1-C6 alkanoylamino and
amino; and
R5 is selected from the group consisting of hydrogen, amino, halogen, hydroxyl,
nitro
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl, cyano, phosphonato, and
hydroxyalkyl; and
Z is selected from the group consisting of optionally substituted heteroaryl selected from the
group consisting of optionally substituted indolyl, furyl, thienyl, pyridyl, benzofuryl,
benzothienyl, imidazolyl, pyrazolyl, thiazolyl, benzothiazolyl, quinolinyl, and 4-(2-
benzyloxazolyl) and phenyl substituted with one or more of amino, halogen, hydroxyl, nitro,
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl and cyano; or a pharmaceutically
acceptable salt thereof.
6. The compound as claimed in claim 5 wherein R1 is methyl, R2 is amino and R5 is H.
7. The compound as claimed in claim 5, wherein R1 is methyl, R2 is C1-C6 alkanoylamino
and R5 is H.
8. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a
compound according to claim 5, or a pharmaceutically acceptable salt thereof.
9. A process for the preparation of a compound of the formula IX

z

wherein R1 is selected from the group consisting of hydrogen, trihalomethyl, C1-C6 alkyl,
and
a group of the formula II

wherein
R3 and R4 are independently selected from the group consisting of hydrogen,
amino,
halogen,, hydroxyl, nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6
trihaloalkyl,
cyano, alkylsulfonyl, sulfamyl, phosphonato and hydroxyalkyl;
Y is a group of the formula
wherein
R2 is selected from the group consisting of C1-C6 alkyl, C1-C6 alkanoylamino and
amino; and
R5 is selected from the group consisting of hydrogen, amino, halogen, hydroxyl,
nitro,
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl, cyano, phosphonato,
and
hydroxyalkyl; and
Z is selected from the group consisting of optionally substituted heteroaryl selected from the
group consisting of optionally substituted indolyl, furyl, thienyl, pyridyl, benzofuryl,

benzothienyl, imidazolyl, pyrazolyl, thiazolyl, benzothiazolyl, quinolinyl, and 4-(2-
benzyloxazolyl) and phenyl substituted with one or more of amino, halogen, hydroxyl, nitro,
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl and cyano;
(a) reacting an oxime of the formula III

with an oxidizing agent selected from the group consisting of N-chloro-p-
toluenesulfonamide, sodium salt, alkaline sodium hypochlorite; chlorine; N-
bromosuccinimide and lead tetraacetate and reacting the resulting nitrile oxide with an alkene
of the formula X
10. The process as claimed in claim 9, wherein R1 is methyl, R2 is amino or n-
propionylamino and R5 is H.
11. A process for the preparation of a compound of the formula IXb'

wherein R1 is selected from the group consisting of hydrogen, trihalomethyl, C1-C6 alkyl
and
a group of the formula II


wherein
R3 and R4 are independently selected from the group consisting of hydrogen, amino,
halogen, hydroxyl, nitro, C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl,
cyano, alkylsulfonyl, sulfamyl, phosphonato and hydroxyalkyl;
R5 is selected from the group consisting of hydrogen, amino, halogen, hydroxyl, nitro,
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl, cyano, phosphonato, and
hydroxyalkyl;
R6 is C1-C6 alkyl;
Z is selected from the group consisting of optionally substituted heteroaryl selected from the
group consisting of optionally substituted indolyl, furyl, thienyl, pyridyl, benzofuryl,
benzothienyl, imidazolyl, pyrazolyl, thiazolyl, benzothiazolyl, quinolinyl, and 4-(2-
benzyloxazolyl) and phenyl substituted with one or more of amino, halogen, hydroxyl, nitro,
C1-C6 alkyl, C1-C6 alkoxy, carboxy, C1-C6 trihaloalkyl and cyano
and M is an alkali metal,
the process comprising:
(a) reacting an oxime of the formula III

with an oxidizing agent selected from the group consisting of N-chloro-p-
toluenesulfonamide, sodium salt, alkaline sodium hypochlorite; chlorine; N-
bromosuccinimide and lead tetraacetate and reacting the resulting nitrile oxide with an alkene
of the formula Xc



(b) treating the compound of the formula IXa with an acylating agent of the formula
XIX

in the presence of a trialkylamine base to provide a compound of the formula IXb

(c) reacting the compound of the formula IXb with an alkali metal base to give the
compound of the formula IXb1.
12. The process as claimed in claim 11, wherein R1 is methyl, R5 is hydrogen, R6 is ethyl
and M is sodium.

The invention discloses a process for the preparation of a compound of the formula (I), wherein R1, Y
and Z are as defined in the specification.

the process comprising: contacting an oxime of the formula III

with an oxidizing agent and reacting the resulting nitrile oxide with an alkyne of the formula IV

The invention is also for 2-isooxazolines of formula (IX).
wherein R1, Y and Z are as defined in the specification and process for its preparation.

Documents:

605-KOLNP-2004-CORRESPONDENCE.pdf

605-KOLNP-2004-FORM 27.pdf

605-KOLNP-2004-FORM-27-1.pdf

605-kolnp-2004-granted-abstract.pdf

605-kolnp-2004-granted-assignment.pdf

605-kolnp-2004-granted-claims.pdf

605-kolnp-2004-granted-correspondence.pdf

605-kolnp-2004-granted-description (complete).pdf

605-kolnp-2004-granted-drawings.pdf

605-kolnp-2004-granted-examination report.pdf

605-kolnp-2004-granted-form 1.pdf

605-kolnp-2004-granted-form 13.pdf

605-kolnp-2004-granted-form 18.pdf

605-kolnp-2004-granted-form 2.pdf

605-kolnp-2004-granted-form 3.pdf

605-kolnp-2004-granted-form 5.pdf

605-kolnp-2004-granted-gpa.pdf

605-kolnp-2004-granted-reply to examination report.pdf

605-kolnp-2004-granted-specification.pdf


Patent Number 225982
Indian Patent Application Number 605/KOLNP/2004
PG Journal Number 48/2008
Publication Date 05-Dec-2008
Grant Date 03-Dec-2008
Date of Filing 11-May-2004
Name of Patentee ONCONOVA THERAPEUTICS, INC.
Applicant Address P.O. BOX 7693, PRINCETON, NJ 08543
Inventors:
# Inventor's Name Inventor's Address
1 REDDY RAMANA M. V. 921 ST. JOSEPH DRIVE, UPPER DARBY, PA 19082
PCT International Classification Number C07D
PCT International Application Number PCT/US02/32612
PCT International Filing date 2002-10-11
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/328,901 2001-10-12 U.S.A.