AU1192699A - Method of using cyclooxygenase-2 inhibitors in maintaining the fetal ductus ateriosus during treatment and prevention of preterm labor - Google Patents

Description

WO 99/22720 PCT/US98/22246 1 METHOD OF USING CYCLOOXYGENASE-2 INHIBITORS IN MAINTAINING THE FETAL DUCTUS ATERIOSUS DURING TREATMENT AND PREVENTION OF PRETERM LABOR 5 Field of the Invention This invention is in the field of the prevention and treatment of preterm labor. More specifically, this invention relates to the use of cyclooxygenase-2 10 inhibitors or derivatives thereof in preventing and treating preterm labor. Background of the Invention 15 Prostaglandins play a major role in the inflammation process and the inhibition of prostaglandin production, especially production of PGG2, PGH2 and PGE2, has been a common target of anti-inflammatory drug discovery. However, common non-steroidal anti 20 inflammatory drugs (NSAID's) that are active in reducing the prostaglandin-induced pain and swelling associated with the inflammation process are also active in affecting other prostaglandin-regulated processes not associated with the inflammation process. Thus, use of 25 high doses of most common NSAID's can produce severe side effects, including life threatening ulcers, that limit their therapeutic potential. An alternative to NSAID's is the use of corticosteroids, which also produce adverse effects, especially when long term 30 therapy is involved. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 2 NSAIDs have been found to prevent the production of prostaglandins by inhibiting enzymes in the human arachidonic acid/prostaglandin pathway, including the enzyme 5 cyclooxygenase (COX). The recent discovery of an inducible enzyme associated with inflammation (named "cyclooxygenase-2 (COX-2)" or "prostaglandin G/H synthase II") provides a viable target of inhibition which more 10 effectively reduces inflammation and produces fewer and less drastic side effects. Spontaneous preterm labor during pregnancy is an important and increasing problem confronting the medical 15 community. Few advances have been made in the understanding of causes of preterm labor, in the early detection of preterm labor and in its general management. The ability to safely stop preterm labor and thereby to allow a pregnancy to advance towards term has 20 thus far eluded the medical and scientific community. Preterm delivery accounts for a major proportion of perinatal deaths and significant proportion of postnatal and childhood defects and therefore, maintaining the fetus in utero is preferred to allowing preterm 25 delivery. Preterm labor also has proven to be a limiting factor for types of fetal intervention. The onset of labor appears to depend on multiple factors. Normal progression of pregnancy until the term 30 requires relaxation of uterine smooth muscle until parturition, but the mechanism that maintains uterine SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 3 relaxation during pregnancy is unknown. Normal parturition typically begins with labor. Labor consists of a series of rhythmic, progressive contractions of the uterus that cause effacement and dilation of the uterine 5 cervix. In normal pregnancy, labor usually begins within two weeks before estimated delivery. Once preterm labor is diagnosed, the risks and benefits of labor inhibition must be weighed against 10 those of allowing delivery to occur. The risks from labor inhibition are primarily related to the side effects of the labor inhibiting drugs. Once preterm labor is diagnosed and the gestational age is established as appropriate for labor inhibition, 15 contraindications such as eclampsia, preeclampsia, ruptured placenta, dead or anomalous fetus, fetal distress or chorioammionitis to premature delivery is determined and the particular available tocolytic agent is selected. 20 Different pharmacological approaches using the above tocolytic drugs have been tried to control preterm labor. Currently used tocolytic agents most often used include p-adrenoreceptor stimulants such as epinephrine 25 or its synthetic analogs and derivatives salbutamol, terbutaline, isoxsuprine, ritodrine, and fenoterol, magnesium sulfate, prostaglandin inhibitors such as aspirin, indomethacin and naproxen, ethanol and calcium channel-blocking agents such as nipedifine or 30 nicardipine. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 4 Even the best tocolytic regimen available currently is unsatisfactory for prevention or inhibition of preterm labor. Additionally to proving ineffective, such standard tocolytic regimen had potentially serious 5 harmful effects on both mother and fetus. Halogenated inhalation anesthesia needed to achieve uterine relaxation had been shown to produce significant myocardial depression in both mother and fetus. Finally, it is becoming obvious that the aggressive treatment of 10 postoperative labor with maximal doses of magnesium and betamimetics is quite toxic for the mother and attempts to avoid maternal pulmonary edema in this clinical setting led to maternal hypovolemia with documented reversal of diastolic flow in the uterine arteries. 15 NSAIDs have been studied in the treatment and prevention of preterm labor. Specifically, indomethacin and sulindac have been clinically evaluated. However, use of these compounds is significantly limited because 20 od side effects including constriction of the fetal ductus arteriosus, and tricuspid regurgitation which can lead to significant right-heart failure in the fetus, among others. Such side effects limit the use of NSAIDs, especially in the all important last trimester. 25 Recently, an increase of cyclooxygenase-2 has been observed during labor (Zuo et al. J. Clin. Endoc. Metab., 79, 894-9 (1994), Slater et al., Am. J. Obstet. Gynecol., 172, 77-82 (1995)). In addition, COX-2 plays 30 a role in spontaneous abortion or preterm labor caused by maternal infection (Silver et al., J. Clin. Invest., SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 5 95, 725-31 (1995)). Sawdy et al. described the use of nimesulide to prevent preterm delivery (The Lancet, 350, 265-6 (1997)). W094/26731, published November 24, 1994, describes the use of thiophene COX-2 inhibitors for the 5 treating premature labor. W097/31631, published Sep. 4, 1997 describes the use of COX-2 inhibitors for managing labor and uterine contractions. Prostaglandins have been indicated in the control 10 of the closure of the ductus arteriosus during the last trimester. Compounds which selectively inhibit cyclooxygenase-2 have been described in U.S. 15 patents 5,380,738, 5,344,991, 5,393,790, 5,434,178, 5,474,995, 5, 510,368 and WO documents W096/06840, W096/03388, W096/03387, W096/25405, W095/15316, W094/15932, W094/27980, W095/00501, W094/13635, W094/20480, and W094/26731. 20 [Pyrazol-1-yl]benzenesulfonamide have been described as inhibitors of cyclooxygenase-2 and have shown promise in the treatment of inflammation, arthritis, and pain, with minimal side effects in pre 25 clinical and clinical trials. Their use for treating inflammation has been described in U.S. Patent No. 5,466,823. However, their use for treating or preventing preterm labor has not been previously described. 30 The present invention is the use of compounds that selectively inhibit COX-2 to treat and prevent preterm SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 6 labor while maintaining circulatory flow through the fetal ductus arteriosus. Detailed Description of the Invention 5 The present invention provides a method for treating or preventing preterm labor while maintaining circulatory flow through the fetal ductus arteriosus in a subject in need of such treatment or prevention, the 10 method comprises treating the subject having or susceptible to said preterm labor with a therapeutically-effective amount of a compound of Formula I R R 15 R3 wherein A is a 5- or 6-member ring substituent selected from partially unsaturated or unsaturated heterocyclo and carbocyclic rings; 20 wherein R1 is at least one substituent selected from heterocyclo, cycloalkyl, cycloalkenyl and aryl, wherein R 1 is optionally substituted at a substitutable position with one or more radicals selected from alkyl, haloalkyl, cyano, carboxyl, 25 alkoxycarbonyl, hydroxyl, hydroxyalkyl, haloalkoxy, amino, alkylamino, arylamino, nitro, alkoxyalkyl, alkylsulfinyl, halo, alkoxy and alkylthio; wherein R 2 is selected from alkyl, and amino; and wherein R 3 is a radical selected from halo, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 7 alkyl, alkenyl, alkynyl, oxo, cyano, carboxyl, cyanoalkyl, heterocyclooxy, alkyloxy, alkylthio, alkylcarbonyl, cycloalkyl, aryl, haloalkyl, heterocyclo, cycloalkenyl, aralkyl, 5 heterocycloalkyl, acyl, alkylthioalkyl, hydroxyalkyl, alkoxycarbonyl, arylcarbonyl, aralkylcarbonyl, aralkenyl, alkoxyalkyl, arylthioalkyl, aryloxyalkyl, aralkylthioalkyl, aralkoxyalkyl, alkoxyaralkoxyalkyl, 10 alkoxycarbonylalkyl, aminocarbonyl, aminocarbonylalkyl, alkylaminocarbonyl, N arylaminocarbonyl, N-alkyl-N-arylaminocarbonyl, alkylaminocarbonylalkyl, carboxyalkyl, alkylamino, N-arylamino, N-aralkylamino, N-alkyl-N 15 aralkylamino, N-alkyl-N-arylamino, aminoalkyl, alkylaminoalkyl, N-arylaminoalkyl, N aralkylaminoalkyl, N-alkyl-N-aralkylaminoalkyl, N alkyl-N-arylaminoalkyl, aryloxy, aralkoxy, arylthio, aralkylthio, alkylsulfinyl, 20 alkylsulfonyl, aminosulfonyl, alkylaminosulfonyl, N-arylaminosulfonyl, arylsulfonyl, N-alkyl-N arylaminosulfonyl; or a pharmaceutically acceptable salt thereof. 25 The invention would be useful for, but not limited to treatment and prevention of preterm labor. The invention also would be useful for, but not limited to prevention of closure of the ductus 30 arteriosus and maintaining circulatory flow through the fetal ductus arteriosus during preterm labor therapy. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 8 Besides being useful for human treatment, these compounds are also useful for veterinary treatment of mammals, including companion animals 5 and farm animals, such as, but not limited to, horses, dogs, cats, cows, sheep and pigs. The term "treatment" includes partial or total inhibition of the preterm labor. 10 The term "prevention" includes either preventing the onset of clinically evident preterm labor altogether or preventing the onset of a preclinically evident stage of preterm labor in individuals at risk. 15 The phrase "therapeutically-effective" is intended to qualify the amount of each agent which will achieve the goal of improvement in severity and the frequency of incidence over treatment of each agent by itself, while 20 avoiding adverse side effects typically associated with alternative therapies. The term "subject" for purposes of treatment includes any human or animal subject who is experiencing 25 preterm labor, and preferably is a human subject. For methods of prevention, the subject is any human or animal subject, and preferably is a human subject who is currently pregnant and at risk for experiencing preterm labor. 30 SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 9 Inhibitors of the cyclooxygenase pathway in the metabolism of arachidonic acid used in the prevention and treatment of preterm labor may inhibit enzyme activity through a variety of 5 mechanisms. By the way of example, the inhibitors used in the methods described herein may block the enzyme activity directly by acting as a substrate for the enzyme. The use of cyclooxygenasse-2 selective inhibitors is highly 10 advantageous in that they minimize the gastric side effects that can occur with non-selective NSAID's, especially where prolonged prophylactic treatment is expected. 15 The term "cyclooxygenase-2 inhibitor" denotes a compound able to inhibit cyclooxygenase-2 without significant inhibition of cyclooxygenase-1. Preferably, it includes compounds which have a cyclooxygenase-2 IC 50 of 20 less than about 0.2 pM, and also have a selectivity ratio of cyclooxygenase-2 inhibition over cyclooxygenase-1 inhibition of at least 50, and more preferably of at least 100. Even more preferably, the compounds have a cyclooxygenase-1 25 IC50 of greater than about 1 pM, and more preferably of greater than 10 pM. The present invention provides a novel method for control, treatment, management and prevention of preterm 30 labor while maintaining circulatory flow through the fetal ductus. The method comprises administering to a SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 10 pregnant woman experiencing preterm labor a composition consisting essentially of a compound of Formula I, alone or in combination with other tocolytic agents in an amount effective to inhibit or counter the onset of 5 uterine contractions. Such tocolytic agents include p adrenoreceptor stimulants such as epinephrine or its synthetic analogs and derivatives salbutamol, terbutaline, isoxsuprine, ritodrine, and fenoterol, magnesium sulfate, ethanol, activin antagonists, cardiac 10 antiarrhythmics such as lidocaine or ocainide, nitric oxide donors such as S-nitroso-N-acetylpenicillamine, nitric oxide nucleophiles and adducts, nitroglycerin, hydroxylamine, sodium azide, diethylamino nitric oxide and analogs, and nitric oxide precursors such as L 15 arginine, and calcium channel-blocking agents such as nipedifine or nicardipine. Derivatives are intended to encompass any compounds which are structurally related to the cyclooxygenase-2 20 inhibitors or which possess the substantially equivalent biologic activity. By way of example, such inhibitors may include, but are not limited to, prodrugs thereof. A preferred class of compounds which inhibit 25 cyclooxygenase-2 consists of compounds of Formula I wherein A is selected from oxazolyl, isoxazolyl, thienyl, dihydrofuryl, furyl, pyrrolyl, pyrazolyl, thiazolyl, imidazolyl, isothiazolyl, cyclopentenyl, phenyl, and pyridyl; wherein R is selected from 30 5- and 6-membered heterocyclo, lower cycloalkyl, lower cycloalkenyl and aryl selected from phenyl, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 11 biphenyls and naphthyl, wherein R1 is optionally substituted at a substitutable position with one or more radicals selected from lower alkyl, lower haloalkyl, cyano, carboxyl, lower alkoxycarbonyl, 5 hydroxyl, lower hydroxyalkyl, lower haloalkoxy, amino, lower alkylamino, phenylamino, nitro, lower alkoxyalkyl, lower alkylsulfinyl, halo, lower alkoxy and lower alkylthio; wherein R 2 is selected from lower alkyl and amino; and wherein R 3 is a 10 radical selected from halo, lower alkyl, oxo, cyano, carboxyl, lower cyanoalkyl, heteroaryloxy, lower alkyloxy, lower cycloalkyl, phenyl, lower haloalkyl, 5- or 6-membered heterocyclo, lower hydroxylalkyl, lower aralkyl, acyl, phenylcarbonyl, 15 lower alkoxyalkyl, heteroaryloxy, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, alkylamino, aminoalkyl, alkylaminoalkyl, aryloxy, and aralkoxy; or a pharmaceutically-acceptable salt thereof. 20 A more preferred class of compounds which inhibit cyclooxygenase-2 consists of compounds of Formula I wherein A is selected from oxazolyl, isoxazolyl, dihydrofuryl, imidazolyl, and pyrazolyl; wherein R1 is selected from 5- and 6 25 membered heterocyclo, lower cycloalkyl, lower cycloalkenyl and aryl selected from phenyl, biphenyl and naphthyl, wherein R1 is optionally substituted at a substitutable position with one or more radicals selected from lower alkyl, lower 30 haloalkyl, cyano, carboxyl, lower alkoxycarbonyl, hydroxyl, lower hydroxyalkyl, lower haloalkoxy, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 12 amino, lower alkylamino, phenylamino, nitro, lower alkoxyalkyl, lower alkylsulfinyl, halo, lower alkoxy and lower alkylthio; wherein R 2 is amino; and wherein R 3 is a radical selected from oxo, 5 cyano, carboxyl, lower alkoxycarbonyl, lower carboxyalkyl, lower cyanoalkyl, halo, lower alkyl, lower alkyloxy, lower cycloalkyl, phenyl, lower haloalkyl, 5- or 6-membered heterocyclo, lower hydroxylalkyl, lower aralkyl, acyl, phenylcarbonyl, 10 lower alkoxyalkyl, 5- or 6-membered heteroaryloxy, aminocarbonyl, lower alkylaminocarbonyl, lower alkylamino, lower aminoalkyl, lower alkylaminoalkyl, phenyloxy, and lower aralkoxy; or a pharmaceutically-acceptable salt thereof. 15 An even more preferred class of compounds which inhibit cyclooxygenase-2 consists of compounds of Formula I wherein A is selected from oxazolyl, isoxazolyl, imidazolyl, and pyrazolyl; 20 wherein R1 is phenyl optionally substituted at a substitutable position with one or more radicals selected from methyl, ethyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, 25 dichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl, fluoromethyl, difluoroethyl, difluoropropyl, dichloroethyl, dichloropropyl, cyano, carboxyl, methoxycarbonyl, hydroxyl, hydroxymethyl, trifluoromethoxy, amino, N 30 methylamino, N,N-dimethylamino, N-ethylamino, N,N dipropylamino, N-butylamino, N-methyl-N-ethylamino, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 13 phenylamino, nitro, methoxymethyl, methylsulfinyl, fluoro, chloro, bromo, methoxy, ethoxy, propoxy, n butoxy, pentoxy, and methylthio; wherein R 2 is amino; and wherein R 3 is a radical selected from 5 oxo, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, carboxypropyl, carboxymethyl, carboxyethyl, cyanomethyl, fluoro, chloro, bromo, methyl, ethyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, fluoromethyl, 10 difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl, fluoromethyl, difluoroethyl, difluoropropyl, dichloroethyl, dichloropropyl, methoxy, ethoxy, propoxy, n-butoxy, pentoxy, 15 cyclohexyl, phenyl, pyridyl, thienyl, thiazolyl, oxazolyl, furyl, pyrazinyl, hydroxylmethyl, hydroxylpropyl, benzyl, formyl, phenylcarbonyl, methoxymethyl, furylmethyloxy, aminocarbonyl, N methylaminocarbonyl, N,N-dimethylaminocarbonyl, 20 N,N-dimethylamino, N-ethylamino, N,N-dipropylamino, N-butylamino, N-methyl-N-ethylamino, aminomethyl, N,N-dimethylaminomethyl, N-methyl-N ethylaminomethyl, benzyloxy, and phenyloxy; or a pharmaceutically-acceptable salt thereof. 25 A family of specific compounds of particular interest within Formula I consists of compounds and pharmaceutically-acceptable salts thereof as follows: 30 3-(3,4-difluorophenyl)-4-(4-methylsulfonylphenyl) 2-(5H)-furanone; SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 14 3-phenyl-4-4-methylsulfonylphenyl)-2-(5H)-furanone; 4- [5- (4--chlorophenyl) -3- (trifluoromethyl) -1H pyrazol-1-yllbenzenesulfonamide; 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H 5 pyrazol-1-yl]benzenesulfonamide; 4-[5-(3-fluoro-4-methoxyphenyl)-3-(difluoromethyl) 1H-pyrazol-i-yl]benzenesulfonamide; 3-[1-[4-(methylsulfonyl)phenyl]-4-trifluoromethyl 1H-imidazol-2-yl]pyridine; 10 2-methyl-5-[1-[4-(methylsulfonyl)phenyl]-4 trifluoromethyl-1H-imidazol-2-yl]pyridine; 4-[2-(5-methylpyridin-3-yl)-4-(trifluoromethyl)-1H imidazol-1-yl]benzenesulfonamide; 4-[5-methyl-3-phenylisoxazol-4 15 yl]benzenesulfonamide; 4-[5-hydroxyethyl-3-phenylisoxazol-4 yl]benzenesulfonamide; [2-trifluoromethyl-5-(3,4-difluorophenyl)-4 oxazolyl]benzenesulfonamide; 20 4-[2-methyl-4-phenyl-5-oxazolyl]benzenesulfonamide; and 4-[5-(3-fluoro-4-methoxyphenyl-2-trifluoromethyl) 4-oxazolyl]benzenesulfonamide. 25 Within Formula I there is a subclass of compounds of high interest represented by Formula II: R 6

R

5 SN N4 H2N - R 2 SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 15 wherein R 4 is selected from hydrido, alkyl, haloalkyl, alkoxycarbonyl, cyano, cyanoalkyl, carboxyl, aminocarbonyl, alkylaminocarbonyl, 5 cycloalkylaminocarbonyl, arylaminocarbonyl, carboxyalkylaminocarbonyl, carboxyalkyl, aralkoxycarbonylalkylaminocarbonyl, aminocarbonylalkyl, alkoxycarbonylcyanoalkenyl and hydroxyalkyl; wherein R 5 is selected from hydrido, alkyl, cyano, 10 hydroxyalkyl, cycloalkyl, alkylsulfonyl and halo; and wherein R 6 is selected from aralkenyl, aryl, cycloalkyl, cycloalkenyl and heterocyclic; wherein R 4 is optionally substituted at a substitutable position with one or more radicals selected from halo, alkylthio, 15 alkylsulfonyl, cyano, nitro, haloalkyl, alkyl, hydroxyl, alkenyl, hydroxyalkyl, carboxyl, cycloalkyl, alkylamino, dialkylamino, alkoxycarbonyl, aminocarbonyl, alkoxy, haloalkoxy, sulfamyl, heterocyclic and amino; or a pharmaceutically-acceptable salt or 20 derivative thereof. A class of compounds of particular interest consists of those compounds of Formula II wherein R 4 is selected from lower haloalkyl; wherein R 5 is hydrido; 25 and wherein R 6 is phenyl optionally substituted at a substitutable position with one or more radicals selected from halo, lower alkyl, and lower alkoxy; or a pharmaceutically-acceptable salt or derivative thereof. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 16 A class of compounds of more particular interest consists of those compounds of Formula II wherein R 4 is selected from trifluoromethyl and difluoromethyl; wherein R 5 is hydrido; and wherein R 6 is phenyl 5 optionally substituted at a substitutable position with one or more radicals selected from fluoro, chloro, methyl, and methoxy; or a pharmaceutically-acceptable salt or derivative thereof. A family of specific compounds of particular 10 interest within Formula II consists of compounds, pharmaceutically-acceptable salts and derivatives thereof as follows: 4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1 15 yl]benzenesulfonamide; 4-[5-phenyl-3-(trifluoromethyl)-lH-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-fluorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 20 4-[5-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-chlorophenyl)-3-(difluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 25 yl]benzenesulfonamide; 4-[3-(difluoromethyl)-5-(4-methylphenyl)-1H-pyrazol-1 yl]benzenesulfonamide; 4-[3-(difluoromethyl)-5-phenyl-1H-pyrazol-1 yl]benzenesulfonamide; 30 4-[3-(difluoromethyl)-5-(4-methoxyphenyl)-1H-pyrazol-1 yllbenzenesulfonamide; SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 17 4-[3-(difluoromethyl)-5- (3-fluoro-4-methoxyphenyl)-lH pyrazol-1-yljbenzenesulfonamide; and 4-[5-(3-fluoro-4-methoxyphenyl)-3-(trifluoromethyl)-lH pyrazol-1-yl]benzenesulfonamide. 5 A family of specific compounds of more particular interest within Formula II consists of compounds and pharmaceutically-acceptable salts or derivatives thereof as follows: 10 4-[S-(4-methylphenyl)-3-(trifluoromethyl)-lH-pyrazol-l yl]benzenesulfonamide; 4-[5-(4-chlorophenyl)-3-(difluoromethyl)-lH-pyrazol-l yl]benzenesulfonamide; and 15 4-[5-(3-fluoro-4-methoxyphenyl)-3-(difluoromethyl)-lH pyrazol-1-yllbenzenesulfonamide. The term "hydrido" denotes a single hydrogen atom (H). This hydrido radical may be attached, 20 for example, to an oxygen atom to form a hydroxyl radical or two hydrido radicals may be attached to a carbon atom to form a methylene (-CH2-) radical. Where used, either alone or within other terms such as "haloalkyl", "alkylsulfonyl", "alkoxyalkyl" and 25 "hydroxyalkyl", the term "alkyl" embraces linear or branched radicals having one to about twenty carbon atoms or, preferably, one to about twelve carbon atoms. More preferred alkyl radicals are "lower alkyl" radicals having one to about ten carbon 30 atoms. Most preferred are lower alkyl radicals having one to about six carbon atoms. Examples of SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 18 such radicals include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert butyl, pentyl, iso-amyl, hexyl and the like. The term "alkenyl" embraces linear or branched radicals 5 having at least one carbon-carbon double bond of two to about twenty carbon atoms or, preferably, two to about twelve carbon atoms. More preferred alkenyl radicals are "lower alkenyl" radicals having two to about six carbon atoms. Examples of 10 alkenyl radicals include ethenyl, propenyl, allyl, propenyl, butenyl and 4-methylbutenyl. The term "alkynyl" denotes linear or branched radicals having at least one carbon-carbon triple bond, and having two to about twenty carbon atoms or, 15 preferably, two to about twelve carbon atoms. More preferred alkynyl radicals are "lower alkynyl" radicals having two to about ten carbon atoms. Most preferred are lower alkynyl radicals having two to about six carbon atoms. Examples of such 20 radicals include propargyl, butynyl, and the like. The terms "alkenyl" and "lower alkenyl", embrace radicals having "cis" and "trans" orientations, or alternatively, "E" and "Z" orientations. The term "cycloalkyl" embraces saturated carbocyclic 25 radicals having three to about twelve carbon atoms. More preferred cycloalkyl radicals are "lower cycloalkyl" radicals having three to about eight carbon atoms. Examples of such radicals include cyclopropyl, cyclobutyl, cyclopentyl and 30 cyclohexyl. The term "cycloalkenyl" embraces partially unsaturated carbocyclic radicals having SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 19 three to twelve carbon atoms. More preferred cycloalkenyl radicals are "lower cycloalkenyl" radicals having four to about eight carbon atoms. Examples of such radicals include cyclobutenyl, 5 cyclopentenyl and cyclohexenyl. The term "halo" means halogens such as fluorine, chlorine, bromine or iodine. The term "haloalkyl" embraces radicals wherein any one or more of the alkyl carbon atoms is substituted with halo as defined above. 10 Specifically embraced are monohaloalkyl, dihaloalkyl and polyhaloalkyl radicals. A monohaloalkyl radical, for one example, may have either an iodo, bromo, chloro or fluoro atom within the radical. Dihalo and polyhaloalkyl radicals may 15 have two or more of the same halo atoms or a combination of different halo radicals. "Lower haloalkyl" embraces radicals having one to six carbon atoms. Examples of haloalkyl radicals include fluoromethyl, difluoromethyl, 20 trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl, difluorochloromethyi, dichlorofluoromethyl, difluoroethyl, difluoropropyl, dichloroethyl and dichloropropyl. 25 The term "hydroxyalkyl" embraces linear or branched alkyl radicals having one to about ten carbon atoms any one of which may be substituted with one or more hydroxyl radicals. More preferred hydroxyalkyl radicals are "lower hydroxyalkyl" 30 radicals having one to six carbon atoms and one or more hydroxyl radicals. Examples of such radicals SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 20 include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl and hydroxyhexyl. The terms "alkoxy" and "alkyloxy" embrace linear or branched oxy containing radicals each having alkyl portions of 5 one to about ten carbon atoms. More preferred alkoxy radicals are "lower alkoxy" radicals having one to six carbon atoms. Examples of such radicals include methoxy, ethoxy, propoxy, butoxy and tert butoxy. The term "alkoxyalkyl" embraces alkyl 10 radicals having one or more alkoxy radicals attached to the alkyl radical, that is, to form monoalkoxyalkyl and dialkoxyalkyl radicals. The "alkoxy" radicals may be further substituted with one or more halo atoms, such as fluoro, chloro or 15 bromo, to provide haloalkoxy radicals. More preferred haloalkoxy radicals are "lower haloalkoxy" radicals having one to six carbon atoms and one or more halo radicals. Examples of such radicals include fluoromethoxy, chloromethoxy, 20 trifluoromethoxy, trifluoroethoxy, fluoroethoxy and fluoropropoxy. The term "aryl", alone or in combination, means a carbocyclic aromatic system containing one, two or three rings wherein such rings may be attached together in a pendent manner 25 or may be fused. The term "aryl" embraces aromatic radicals such as phenyl, naphthyl, tetrahydronaphthyl, indane and biphenyl. Aryl moieties may also be substituted at a substitutable position with one or more substituents selected 30 independently from alkyl, alkoxyalkyl, alkylaminoalkyl, carboxyalkyl, alkoxycarbonylalkyl, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 21 aminocarbonylalkyl, alkoxy, aralkoxy, hydroxyl, amino, halo, nitro, alkylamino, acyl, cyano, carboxy, aminocarbonyl, alkoxycarbonyl and aralkoxycarbonyl. The term "heterocyclo" embraces 5 saturated, partially unsaturated and unsaturated heteroatom-containing ring-shaped radicals, where the heteroatoms may be selected from nitrogen, sulfur and oxygen. Examples of saturated heterocyclo radicals include saturated 3 to 6 10 membered heteromonocylic group containing 1 to 4 nitrogen atoms (e.g. pyrrolidinyl, imidazolidinyl, piperidino, piperazinyl, etc.); saturated 3 to 6 membered heteromonocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms (e.g. 15 morpholinyl, etc.); saturated 3 to 6-membered heteromonocyclic group containing 1 to 2 sulfur atoms and 1 to 3 nitrogen atoms (e.g., thiazolidinyl, etc.). Examples of partially unsaturated heterocyclo radicals include 20 dihydrothiophene, dihydropyran, dihydrofuran and dihydrothiazole. The term "heteroaryl" embraces unsaturated heterocyclo radicals. Examples of heteroaryl radicals include unsaturated 3 to 6 membered heteromonocyclic group containing 1 to 4 25 nitrogen atoms, for example, pyrrolyl, pyrrolinyl, imidazolyl, pyrazolyl, pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, triazolyl (e.g., 4H-1,2,4 triazolyl, 1H-1,2,3-triazolyl, 2H-1,2,3-triazolyl, etc.) tetrazolyl (e.g. 1H-tetrazolyl, 2H 30 tetrazolyl, etc.), etc.; unsaturated condensed heterocyclo group containing 1 to 5 nitrogen atoms, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 22 for example, indolyl, isoindolyl, indolizinyl, benzimidazolyl, quinolyl, isoquinolyl, indazolyl, benzotriazolyl, tetrazolopyridazinyl (e.g., tetrazolo[1,5-b]pyridazinyl, etc.), etc.; 5 unsaturated 3 to 6-membered heteromonocyclic group containing an oxygen atom, for example, pyranyl, furyl, etc.; unsaturated 3 to 6-membered heteromonocyclic group containing a sulfur atom, for example, thienyl, etc.; unsaturated 3- to 6 10 membered heteromonocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms, for example, oxazolyl, isoxazolyl, oxadiazolyl (e.g., 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,5 oxadiazolyl, etc.) etc.; unsaturated condensed 15 heterocyclo group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms (e.g. benzoxazolyl, benzoxadiazolyl, etc.); unsaturated 3 to 6-membered heteromonocyclic group containing 1 to 2 sulfur atoms and 1 to 3 nitrogen atoms, for example, 20 thiazolyl, thiadiazolyl (e.g., 1,2,4- thiadiazolyl, 1,3,4-thiadiazolyl, 1,2,5-thiadiazolyl, etc.) etc.; unsaturated condensed heterocyclo group containing 1 to 2 sulfur atoms and 1 to 3 nitrogen atoms (e.g., benzothiazolyl, benzothiadiazolyl, etc.) and 25 the like. The term "heteroaryl"also embraces radicals where heterocyclo radicals are fused with aryl radicals. Examples of such fused bicyclic radicals include benzofuran, benzothiophene, and the like. Said "heterocyclo group" may have 1 to 3 30 substituents such as alkyl, hydroxyl, halo, alkoxy, oxo, amino and alkylamino. The term "alkylthio" SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 23 embraces radicals containing a linear or branched alkyl radical, of one to about ten carbon atoms attached to a divalent sulfur atom. More preferred alkylthio radicals are "lower alkylthio" radicals 5 having alkyl radicals of one to six carbon atoms. Examples of such lower alkylthio radicals are methylthio, ethylthio, propylthio, butylthio and hexylthio. The term "alkylthioalkyl" embraces radicals containing an alkylthio radical attached 10 through the divalent sulfur atom to an alkyl radical of one to about ten carbon atoms. More preferred alkylthioalkyl radicals are "lower alkylthioalkyl" radicals having alkyl radicals of one to six carbon atoms. Examples of such lower 15 alkylthioalkyl radicals include methylthiomethyl. The term "alkylsulfinyl" embraces radicals containing a linear or branched alkyl radical, of one to about ten carbon atoms, attached to a divalent -S(=O)- radical. More preferred 20 alkylsulfinyl radicals are "lower alkylsulfinyl" radicals having alkyl radicals of one to six carbon atoms. Examples of such lower alkylsulfinyl radicals include methylsulfinyl, ethylsulfinyl, butylsulfinyl and hexylsulfinyl. The term 25 "sulfonyl", whether used alone or linked to other terms such as "alkylsulfonyl", denotes a divalent radical, -SO 2 -. "Alkylsulfonyl" embraces alkyl radicals attached to a sulfonyl radical, where alkyl is defined as above. More preferred 30 alkylsulfonyl radicals are "lower alkylsulfonyl" radicals having one to six carbon atoms. Examples SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 24 of such lower alkylsulfonyl radicals include methylsulfonyl, ethylsulfonyl and propylsulfonyl. The "alkylsulfonyl" radicals may be further substituted with one or more halo atoms, such as 5 fluoro, chloro or bromo, to provide haloalkylsulfonyl radicals. The terms "sulfamyl", "aminosulfonyl" and "sulfonamidyl" denote NH 2 02S-. The term "acyl" denotes a radical provided by the residue after removal of hydroxyl from an organic 10 acid. Examples of such acyl radicals include alkanoyl and aroyl radicals. Examples of such lower alkanoyl radicals include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, trifluoroacetyl. 15 The term "carbonyl", whether used alone or with other terms, such as "alkoxycarbonyl", denotes (C=O)-. The term "aroyl" embraces aryl radicals with a carbonyl radical as defined above. Examples of aroyl include benzoyl, naphthoyl, and the like 20 and the aryl in said aroyl may be additionally substituted. The terms "carboxy" or "carboxyl", whether used alone or with other terms, such as "carboxyalkyl", denotes -CO 2 H. The term "carboxyalkyl" embraces alkyl radicals substituted 25 with a carboxy radical. More preferred are "lower carboxyalkyl" which embrace lower alkyl radicals as defined above, and may be additionally substituted on the alkyl radical with halo. Examples of such lower carboxyalkyl radicals include carboxymethyl, 30 carboxyethyl and carboxypropyl. The term "alkoxycarbonyl" means a radical containing an SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 25 alkoxy radical, as defined above, attached via an oxygen atom to a carbonyl radical. More preferred are "lower alkoxycarbonyl" radicals with alkyl porions having one to six carbons. Examples of 5 such lower alkoxycarbonyl (ester) radicals include substituted or unsubstituted methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl and hexyloxycarbonyl. The terms "alkylcarbonyl", "arylcarbonyl" and "aralkylcarbonyl" include 10 radicals having alkyl, aryl and aralkyl radicals, as defined herein, attached to a carbonyl radical. Examples of such radicals include substituted or unsubstituted methylcarbonyl, ethylcarbonyl, phenylcarbonyl and benzylcarbonyl. The term 15 "aralkyl" embraces aryl-substituted alkyl radicals such as benzyl, diphenylmethyl, triphenylmethyl, phenylethyl, and diphenylethyl. The aryl in said aralkyl may be additionally substituted with halo, alkyl, alkoxy, halkoalkyl and haloalkoxy. The 20 terms benzyl and phenylmethyl are interchangeable. The term "heterocycloalkyl" embraces saturated and partially unsaturated heterocyclo-substituted alkyl radicals, such as pyrrolidinylmethyl, and heteroaryl-substituted alkyl radicals, such as 25 pyridylmethyl, quinolylmethyl, thienylmethyl, furylethyl, and quinolylethyl. The heteroaryl in said heteroaralkyl may be additionally substituted with halo, alkyl, alkoxy, halkoalkyl and haloalkoxy. The term "aralkoxy" embraces aralkyl 30 radicals attached through an oxygen atom to other radicals. The term "aralkoxyalkyl" embraces SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 26 aralkoxy radicals attached through an oxygen atom to an alkyl radical. The term "aralkylthio" embraces aralkyl radicals attached to a sulfur atom. The term "aralkylthioalkyl" embraces 5 aralkylthio radicals attached through a sulfur atom to an alkyl radical. The term "aminoalkyl" embraces alkyl radicals substituted with amino radicals. More preferred are "lower aminoalkyl" radicals. Examples of such radicals include 10 aminomethyl, aminoethyl, and the like. The term "alkylamino" denotes amino groups which are substituted with one or two alkyl radicals. Preferred are "lower alkylamino" radicals having alkyl porions having one to six carbon atoms. 15 Suitable lower alkylamino may be monosubstituted N alkylamino or disubstituted N,N-alkylamino, such as N-methylamino, N-ethylamino, N,N-dimethylamino, N,N-diethylamino or the like. The term "arylamino" denotes amino groups which are substituted with one 20 or two aryl radicals, such as N-phenylamino. The "arylamino" radicals may be further substituted on the aryl ring portion of the radical. The term "aralkylamino" embraces amino groups which are substituted with one or two aralkyl radicals. The 25 terms "N-arylaminoalkyl" and "N-aryl-N-alkyl aminoalkyl" denote aminoalkyl groups which are substituted with one aryl radical or one aryl and one alkyl radical, respectively. Examples of such radicals include N-phenylaminomethyl and N-phenyl 30 N-methylaminomethyl. The term "aminocarbonyl" denotes an amide group of the formula -C(=O)NH2. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 27 The term "alkylaminocarbonyl" denotes an aminocarbonyl group which has been substituted with one or two alkyl radicals on the amino nitrogen atom. Preferred are "N-alkylaminocarbonyl" and 5 "N,N-dialkylaminocarbonyl" radicals. More preferred are "lower N-alkylaminocarbonyl" and "lower N,N-dialkylaminocarbonyl" radicals with lower alkyl portions as defined above. The term "alkylaminoalkyl" embraces radicals having one or 10 more alkyl radicals attached to an aminoalkyl radical. The term "aryloxyalkyl" embraces radicals having an aryl radicals attached to an alkyl radical through a divalent oxygen atom. The term "arylthioalkyl" embraces radicals having an aryl 15 radicals attached to an alkyl radical through a divalent sulfur atom. The compounds utilized in the methods of the present invention may be present in the form of free bases or pharmaceutically acceptable acid addition salts 20 thereof. 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. The nature of the salt is not critical, provided that it is pharmaceutically-acceptable. Suitable 25 pharmaceutically-acceptable acid addition salts of compounds of Formula I 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 30 organic acids may be selected from aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 28 carboxylic and sulfonic classes of organic acids, example of which are formic, acetic, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric, ascorbic, glucuronic, maleic, fumaric, pyruvic, 5 aspartic, glutamic, benzoic, anthranilic, mesylic, 4 hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethanesulfonic, benzenesulfonic, pantothenic, 2-hydroxyethanesulfonic, toluenesulfonic, sulfanilic, cyclohexylaminosulfonic, 10 stearic, algenic, P-hydroxybutyric, salicylic, galactaric and galacturonic acid. Suitable pharmaceutically-acceptable base addition salts of compounds of Formula I include metallic salts made from aluminum, calcium, lithium, magnesium, potassium, sodium 15 and zinc or organic salts made from N,N' dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N methylglucamine) and procaine. All of these salts may be prepared by conventional means from the corresponding 20 compound of Formula I by reacting, for example, the appropriate acid or base with the compound of Formula I. GENERAL SYNTHETIC PROCEDURES 25 The cyclooxygenase-2 inhibitor compounds of the invention can be synthesized according to the following procedures of Schemes I-X, wherein the

R

1

-R

3 substituents are as defined for Formula I, above, except where further noted. 30 SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 29 Scheme I R 0 Base 11 3 C R -CCH 3 RiCO 2

CH

3 R O 0 1 2 EtOH, A SNHNH2 O 2 0R 2 00 R 0 N R / + N 3 N \ R R 3 4 Synthetic Scheme I shows the preparation of 5 cyclooxygenase-2 inhibitor compounds, as described in U.S. patent No. 5,521,207 and WQ95/15316, which are incorporated by reference, embraced by Formula I . In step 1, ketone 1 is treated with a base, preferably NaOMe or NaH, and 10 an ester, or ester equivalent, to form the intermediate diketone 2 (in the enol form) which is used without further purification. In step 2, diketone 2 in an anhydrous protic solvent, such as absolute ethanol or acetic acid, is treated 15 with the hydrochloride salt or the free base of a substituted hydrazine at reflux to afford a mixture of pyrazoles 3 and 4. Recrystallization or chromatography affords 3 usually as a solid. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 30 Similar pyrazoles can be prepared by methods described in U.S. Pat. Nos. 4,146,721, 5,051,518, 5,134,142 and 4,914,121 which also are incorporated by reference. 5 Scheme II

SR

2 1) Base R SR 2 0 O 5 6 RaNHNH 2 S0 2

R

2 SR 2 R Oxidize R P

R

3 /,N R N N Ra R N Ra R 8 7 10 Scheme II shows the four step procedure for forming cyclooxygenase-2 inhibitor pyrazoles 8 as described in U.S. patent No. 5,486,534 (where Ra is hydrido or alkyl) from ketones 5. In step 1, ketone 5 is reacted with a base, such as lithium 15 bis(trimethylsilyl)amide or lithium diisopropylamide (LDA) to form the anion. In step 2, the anion is reacted with an acetylating reagent to provide diketone 6. In step 3, the reaction of diketone 6 with hydrazine or a 20 substituted hydrazine, gives pyrazole 7. In step 4, the pyrazole 7 is oxidized with an oxidizing reagent, such as Oxone@ (potassium peroxymonosulfate), 3-chloroperbenzoic acid (MCPBA) or hydrogen peroxide, to give a mixture 25 of the desired 3-(alkylsulfonyl)phenyl-pyrazole 8 and the 5-(alkylsulfonyl)phenyl-pyrazole isomer. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 31 The desired pyrazole 8, usually a white or pale yellow solid, is obtained in pure form either by chromatography or recrystallization. Alternatively, diketone 6 can be formed from 5 ketone 5 by treatment with a base, such as sodium hydride, in a solvent, such as dimethylformamide, and further reacting with a nitrile to form an aminoketone. Treatment of the aminoketone with acid forms the diketone 6. Similar pyrazoles can 10 be prepared by methods described in U.S. Pat. No. 3,984,431 which is incorporated by reference. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 32 Scheme III S02R 2

SO

2 R2 R bO OTb + R R O O Base HO ORb 0 T 9 10 0 0 11 aq. NaOH, SO2R2 2 ORb T 0 R 12 HO OH T 0 0 13 Cu, A N S0 2

R

2 SO2R2 R3 T T 15 14 5 Cyclooxygenase-2 inhibitor diaryl/heteroaryl thiophenes (where T is S, and Rb is alkyl) can be prepared by the methods described in U.S. Patent Nos. 4,427,693, 4,302,461, 4,381,311, 4,590,205, and 4,820,827, and PCT documents WO 95/00501 and 10 W094/15932, which are incorporated by reference. Similar pyrroles (where T is N), furanones and SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 33 furans (where T is 0) can be prepared by methods described in PCT documents WO 95/00501 and W094/15932, and in EP799,823. 5 Scheme IV NaH OTB

R

2 S TBSC1 R 2 S 17 16 I MCPBA OH TBSO R222 R2O2!8 19 18 R 3COCl Base R3 3 RON 0 0

NH

4 OAc R HOAc 0

R

2 0 2 s 0 R2O2 R 0 2 Sj 20 21 Cyclooxygenase-2 inhibitor diaryl/heteroaryl oxazoles can be prepared by the methods described 10 in U.S. Patent Nos. 3,743,656, 3,644,499 and 3,647,858, and PCT documents WO 95/00501 and W094/27980, which are incorporated by reference. Equivalent oxazole compounds can be prepared via W096/19463 and W096/19462. 15 Scheme V SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 34 NOH N-C 3 R1 1) 2 eq. n-BuLi R1 OH 2) (R 3 CO) 2 0 22 23 1) ClSO3H 2) NH 4 OH N-C 3 R So 2

NH

2 24 Cyclooxygenase-2 inhibitor diaryl/heteroaryl isoxazoles can be prepared by the methods 5 described in United States No. 5,633,272, PCT documents W092/05162, and W092/19604, and European Publication EP 26928 which are incorporated by reference. Sulfonamides 24 can be formed from the hydrated isoxazole 23 in a two 10 step procedure. First, hydrated isoxazole 23 is treated at about 0 0 C with two or three equivalents of chlorosulfonic acid to form the corresponding sulfonyl chloride. In step two, the sulfonyl chloride thus formed is treated with 15 concentrated ammonia to provide the sulfonamide derivative 24. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 35 Scheme VI OO /Alkylaluminum NH RICN + NH Reagent

R

2 Solvent R 25 26 27 S0 2

R

2 Rb X),yR 3 Alkylation; O base

R

3

R

3 N OH N J>R' R Dehydration RI N R N

SO

2 S0 2

R

2 28 29 Scheme VI shows the three step preparation 5 of the cyclooxygenase-2 inhibitor imidazoles 29 of the present invention. In step 1, the reaction of substituted nitriles (R'CN) 25 with primary phenylamines 26 in the presence of alkylaluminum reagents such as trimethylaluminum, 10 triethylaluminum, dimethylaluminum chloride, diethylaluminum chloride in the presence of inert solvents such as toluene, benzene, and xylene, gives amidines 27. In step 2, the reaction of amidine 27 with 2-haloketones (where X is Br or 15 Cl) in the presence of bases, such as sodium bicarbonate, potassium carbonate, sodium carbonate, potassium bicarbonate or hindered SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 36 tertiary amines such as N,N' diisopropylethylamine, gives the 4,5 dihydroimidazoles 28 (where Rb is alkyl). Some of the suitable solvents for this reaction are 5 isopropanol, acetone and dimethylformamide. The reaction may be carried out at temperatures of about 20'C to about 90 0 C. In step 3, the 4,5 dihydroimidazoles 28 may be dehydrated in the presence of an acid catalyst such as 4 10 toluenesulfonic acid or mineral acids to form the 1,2-disubstituted imidazoles 29 of the invention. Suitable solvents for this dehydration step are e.g., toluene, xylene and benzene. Trifluoroacetic acid can be used as solvent and 15 catalyst for this dehydration step. In some cases (e.g., where R 3 = methyl or phenyl) the intermediate 28 may not be readily isolable. The reaction, under the conditions described above, proceeds to give the targeted 20 imidazoles directly. Similarly, imidazoles can be prepared having the sulfonylphenyl moiety attached at position 2 and R 1 attached at the nitrogen atom at position 1. Diaryl/heteroaryl imidazoles can be prepared 25 by the methods described in U.S. Patent Nos. 4,822,805, U.S. application Serial No. 08/282,395 and PCT document WO 93/14082, which are incorporated by reference. 30 Scheme VII SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 37 0 OTMS R H TMSCN R'lICN catalyst H 30 31 1) Base 0 2) H SR 1) Base 32 2) SR 0 R SRkr OH 33 xidizing SR2 agent 0 34 NH OAc' HOAc R CHO

R

2 S0 2

R

2 N NP R3 Oxidation R R R H H 35 36 The subject imidazole cyclooxygenase-2 inhibitor compounds 36 of this invention may be 5 synthesized according to the sequence outlined in Scheme VII. Aldehyde 30 may be converted to the protected cyanohydrin 31 by reaction with a trialkylsilyl cyanide, such as trimethylsilyl cyanide (TMSCN) in the presence of a catalyst 10 such as zinc iodide (ZnI 2 ) or potassium cyanide SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 38 (KCN). Reaction of cyanohydrin 31 with a strong base followed by treatment with benzaldehyde 32 (where R 2 is alkyl) and using both acid and base treatments, in that order, on workup gives 5 benzoin 33. Examples of strong bases suitable for this reaction are lithium diisopropylamide (LDA) and lithium hexamethyldisilazane. Benzoin 33 may be converted to benzil 34 by reaction with a suitable oxidizing agent, such as bismuth oxide 10 or manganese dioxide, or by a Swern oxidation using dimethyl sulfoxide (DMSO) and trifluoroacetic anhydride. Benzil 34 may be obtained directly by reaction of the anion of cyanohydrin 31 with a substituted benzoic acid 15 halide. Any of compounds 33 and 34 may be used as intermediates for conversion to imidazoles 35 (where R 2 is alkyl) according to chemical procedures known by those skilled in the art and described by M. R. Grimmett, "Advances in 20 Imidazole Chemistry" in Advances in Heterocyclic Chemistry, 12, 104 (1970). The conversion of 34 to imidazoles 35 is carried out by reaction with ammonium acetate and an appropriate aldehyde

(R

3 CHO) in acetic acid. Benzoin 36 may be 25 converted to imidazoles 38 by reaction with formamide. In addition, benzoin 36 may be converted to imidazoles by first acylating with an appropriate acyl group (R 3 CO-) and then treating with ammonium hydroxide. Those skilled 30 in the art will recognize that the oxidation of the sulfide (where R 2 is methyl) to the sulfone may be carried out at any point along the way beginning with compounds 35, and including oxidation of imidazoles 38, using, for examples, 35 reagents such as hydrogen peroxide in acetic acid, m-chloroperoxybenzoic acid (MCPBA) and potassium peroxymonosulfate (OXONE®). SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 39 Diaryl/heteroaryl imidazoles can be prepared by the methods described in U.S. Patent Nos. 3,707,475, 4,686,231, 4,503,065, 4,472,422, 5 4,372,964, 4,576,958, 3,901,908, U.S. application Serial No. 08/281,903 European publication EP 372,445, and PCT document WO 95/00501, which are incorporated by reference. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 40 Scheme VIII

R

2 S0 2 & Br 1.n-BuLi, THF, -78*C R 2 S0 2 & ZnCl 2. ZnCl 2 37 38 Br 3 Pd, 3 Br 39 S0 2

R

2 S0 2

R

2 ClZn ~ 1.n-BuLi, THF, -78*C Br ~ 2. ZnCl 2

R

3

R

3

R

3

R

3 41 40 Pdo RBr S0 2 R 2 R'

R

3

R

3 42 Diaryl/heteroaryl cyclopentene 5 cyclooxygenase-2 inhibitors can be prepared by the methods described in U.S. Patent No. 5,344,991, and PCT document WO 95/00501, which are incorporated by reference. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 41 Scheme IX

SO

2

R

2 __ Pd , PhCH 3 , R 1

C

2 HsOH, Br + R B(OH) 2 Na 2

CO

3 , A \ / R 3 %3 R3

R

3

R

3 44 43 Similarly, Synthetic Scheme IX shows the 5 procedure for the preparation of 1,2 diarylbenzene cyclooxygenase-2 inhibitor agents 44 from 2-bromo-biphenyl intermediates 43 (prepared similar to that described in Synthetic Scheme VIII) and the appropriate substituted 10 phenylboronic acids. Using a coupling procedure similar to the one developed by Suzuki et al. [Synth. Commun., 11, 513 (1981)], intermediates 43 are reacted with the boronic acids in toluene/ethanol at reflux in the presence of a 15 Pd' catalyst, e.g., tetrakis(triphenylphosphine)palladium(0), and 2M sodium carbonate to give the corresponding 1,2 diarylbenzene antiinflammatory agents 44 of this invention. Such terphenyl compounds can be 20 prepared by the methods described in PCT patent document W096/16934, which is incorporated by reference. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 42 Scheme X 0 Iy.O 2 0 R 0,11 Br 2*S + HN R3 CHCN, EtOH s HNA I/-R R O R1N R 43 46 47 5 Diaryl/heteroaryl thiazole cyclooxygenase-2 inhibitors can be prepared by the methods described in U.S. Patent No. 4,051,250, 4,632,930, European Application EP 592,664, and PCT documents W096/03392 and WO 95/00501, which 10 are incorporated by reference. Isothiazoles can be prepared as described in PCT document WO 95/00501. Diaryl/heteroaryl pyridine cyclooxygenase-2 15 inhibitors can be prepared by the methods described in U.S. Patent Nos. 5,169,857, 4,011,328, 4,533,666, and W096/24584 and W096/24585, which are incorporated by reference. 20 Biological Evaluation The efficacy of cyclooxygenase-2 inhibitors in treatment of preterm labor is established in the following models: 25 A human fetal membrane model is performed with materials, reagents and procedures essentially as described by Slater et al. [Am. J. Obstet. Gynecol., 172, 77-82 (1995)]. A COX-2 inhibitor should be active 30 at a dose of 20 mg/kg. SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 43 The efficacy of cyclooxygenase-2 inhibitors in preventing closure of the ductus arteriosus is established in the following model: 5 A sheep model is performed with materials, reagents and procedures essentially as described by Velvis et al. [Pediatr. Res., 30, 62-8 (1991)]. A COX-2 inhibitor should be active at a dose of 20 mg/kg. 10 Materials and Methods The active compounds of the present invention may be administered by any suitable route known to those skilled in the art, preferably in the form of a 15 pharmaceutical composition adapted to such a route, and in a dose effective for the treatment intended. The active compounds and composition may, for example, be administered orally, intravascularly, intraperitoneally, intranasal, intrabronchial, subcutaneously, intra 20 muscularly or topically (including aerosol). The administration of the present invention may be for either prevention or treatment purposes. The methods and compositions used herein may be used alone or in 25 conjunction with additional therapies known to those skilled in the art in the prevention or treatment of preterm labor. Alternatively, the methods and compositions described herein may be used as adjunct therapy. By way of example, the cyclooxygenase-2 30 inhibitor may be administered alone or in conjunction with other agents that are useful for treating or preventing preterm labor. The phrase "adjunct therapy" (or "combination 35 therapy"), in defining use of a cyclooxygenase-2 inhibitor agent and another pharmaceutical agent, is intended to embrace administration of each agent in a SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 44 sequential manner in a regimen that will provide beneficial effects of the drug combination, and is intended as well to embrace co-administration of these agents in a substantially simultaneous manner, such as 5 in a single formulation having a fixed ratio of these active agents, or in multiple, separate formulations for each agent. The present invention also comprises a pharmaceutical composition for the adjunct prevention and treatment of preterm labor, comprising a 10 therapeutically-effective amount of a compound of Formula I in association with at least one pharmaceutically-acceptable carrier, adjuvant or diluent (collectively referred to herein as "carrier" materials) and, other agents or other growth inhibiting agents or 15 other drugs or nutrients. For oral administration, the pharmaceutical composition may be in the form of, for example, a tablet, capsule, suspension or liquid. The pharma 20 ceutical composition is preferably made in the form of a dosage unit containing a particular amount of the active ingredient. Examples of such dosage units are capsules, tablets, powders, granules or a suspension, with conventional additives such as lactose, mannitol, corn 25 starch or potato starch; with binders such as crystalline cellulose, cellulose derivatives, acacia, corn starch or gelatins; with disintegrators such as corn starch, potato starch or sodium carboxymethyl cellulose; and with lubricants such as talc or magnesium 30 stearate. The active ingredient may also be administered by injection as a composition -wherein, for example, saline, dextrose or water may be used as a suitable carrier. 35 For intravenous, intramuscular, subcutaneous, or intraperitoneal administration, the compound may be combined with a sterile aqueous solution which is SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 45 preferably isotonic with the blood of the recipient. Such formulations may be prepared by dissolving solid active ingredient in water containing physiologically compatible substances such as sodium chloride, glycine, 5 and the like, and having a buffered pH compatible with physiological conditions to produce an aqueous solution, and rendering said solution sterile. The formulations may be present in unit or multi-dose containers such as sealed ampoules or vials. 10 Formulations suitable for parenteral administration conveniently comprise a sterile aqueous preparation of the active compound which is preferably made isotonic. Preparations for injections may also be formulated by 15 suspending or emulsifying the compounds in non-aqueous solvent, such as vegetable oil, synthetic aliphatic acid glycerides, esters of higher aliphatic acids or propylene glycol. 20 Formulations for topical use include known gels, creams, oils, and the like. For aerosol delivery, the compounds may be formulated with known aerosol exipients, such as saline, and administered using commercially available nebulizers. Formulation in a 25 fatty acid source may be used to enhance biocompatibility. For rectal administration, the active ingredient may be formulated into suppositories using bases which 30 are solid at room temperature and melt or dissolve at body temperature. Commonly used bases include cocoa butter, glycerinated gelatin, hydrogenated vegetable oil, polyethylene glycols of various molecular weights, and fatty esters of polyethylene stearate. 35 The dosage form and amount can be readily established by reference to known preterm labor SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 46 treatment or prophylactic regiments. The amount of therapeutically active compound that is administered and the dosage regimen for treating a disease condition with the compounds and/or compositions of this invention 5 depends on a variety of factors, including the age, weight, sex and medical condition of the subject, the severity of the disease, the route and frequency of administration, and the particular compound employed, as well as the pharmacokinetic properties of the individual 10 treated, and thus may vary widely. The dosage will generally be lower if the compounds are administered locally rather than systemically, and for prevention rather than for treatment. Such treatments may be administered as often as necessary and for the period of 15 time judged necessary by the treating physician. One of skill in the art will appreciate that the dosage regime or therapeutically effective amount of the inhibitor to be administrated may need to be optimized for each individual. The pharmaceutical compositions may contain 20 active ingredient in the range of about 0.1 to 2000 mg, preferably in the range of about 0.5 to 500 mg and most preferably between about 1 and 200 mg. A daily dose of about 0.01 to 100 mg/kg body weight, preferably between about 0.1 and about 50 mg/kg body weight and most 25 preferably from about 1 to 20 mg/kg body weight, may be appropriate. The daily dose can be administered in one to four doses per day. All documents referenced herein are incorporated by 30 reference. Although this invention has been described with respect to specific embodiments, the details of these embodiments are not to be construed as 35 limitations. SUBSTITUTE SHEET (RULE 26)

Claims (20)

1. A method of maintaining circulation through fetal ductus arteriosus during treatment or prevention 5 of preterm labor in a subject in need of such treatment of prevention, said method comprising treating the subject with a therapeutically-effective amount of a compound of Formula I: R R1 O - A 10 R3 wherein A is a 5- or 6-member ring substituent selected from partially unsaturated or unsaturated heterocyclo and carbocyclic rings; 15 wherein R1 is at least one substituent selected from heterocyclo, cycloalkyl, cycloalkenyl and aryl, wherein R1 is optionally substituted at a substitutable position with one or more radicals selected from alkyl, haloalkyl, cyano, carboxyl, 20 alkoxycarbonyl, hydroxyl, hydroxyalkyl, haloalkoxy, amino, alkylamino, arylamino, nitro, alkoxyalkyl, alkylsulfinyl, halo, alkoxy and alkylthio; wherein R 2 is selected from alkyl, and amino; and wherein R 3 is a radical selected from halo, 25 alkyl, alkenyl, alkynyl, oxo, cyano, carboxyl, cyanoalkyl, heterocyclooxy, alkyloxy, alkylthio, alkylcarbonyl, cycloalkyl, aryl, haloalkyl, heterocyclo, cycloalkenyl, aralkyl, heterocycloalkyl, acyl, alkylthioalkyl, 30 hydroxyalkyl, alkoxycarbonyl, arylcarbonyl, aralkylcarbonyl, aralkenyl, alkoxyalkyl, arylthioalkyl, aryloxyalkyl, aralkylthioalkyl, aralkoxyalkyl, alkoxyaralkoxyalkyl, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 48 alkoxycarbonylalkyl, aminocarbonyl, aminocarbonylalkyl, alkylaminocarbonyl, N arylaminocarbonyl, N-alkyl-N-arylaminocarbonyl, alkylaminocarbonylalkyl, carboxyalkyl, alkylamino, 5 N-arylamino, N-aralkylamino, N-alkyl-N aralkylamino, N-alkyl-N-arylamino, aminoalkyl, alkylaminoalkyl, N-arylaminoalkyl, N aralkylaminoalkyl, N-alkyl-N-aralkylaminoalkyl, N alkyl-N-arylaminoalkyl, aryloxy, aralkoxy, 10 arylthio, aralkylthio, alkylsulfinyl, alkylsulfonyl, aminosulfonyl, alkylaminosulfonyl, N-arylaminosulfonyl, arylsulfonyl, N-alkyl-N arylaminosulfonyl; or a pharmaceutically acceptable salt thereof. 15

2. The method of Claim 1 wherein A is selected from oxazolyl, isoxazolyl, thienyl, dihydrofuryl, furyl, pyrrolyl, pyrazolyl, thiazolyl, imidazolyl, isothiazolyl, cyclopentenyl, phenyl, and pyridyl; 20 wherein R 1 is selected from 5- and 6-membered heterocyclo, lower cycloalkyl, lower cycloalkenyl and aryl selected from phenyl, biphenyl and naphthyl, wherein R1 is optionally substituted at a substitutable position with one or more radicals 25 selected from lower alkyl, lower haloalkyl, cyano, carboxyl, lower alkoxycarbonyl, hydroxyl, lower hydroxyalkyl, lower haloalkoxy, amino, lower alkylamino, phenylamino, nitro, lower alkoxyalkyl, lower alkylsulfinyl, halo, lower alkoxy and lower 30 alkylthio; wherein R 2 is selected from lower alkyl and amino; and wherein R 3 is a radical selected from halo, lower alkyl, oxo, cyano, carboxyl, lower cyanoalkyl, heteroaryloxy, lower alkyloxy, lower cycloalkyl, phenyl, lower haloalkyl, 5- or 6 35 membered heterocyclo, lower hydroxylalkyl, lower aralkyl, acyl, phenylcarbonyl, lower alkoxyalkyl, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 49 heteroaryloxy, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, alkylamino, aminoalkyl, alkylaminoalkyl, aryloxy, and aralkoxy; or a pharmaceutically-acceptable salt thereof. 5

3. The method of Claim 2 wherein A is selected from oxazolyl, isoxazolyl, dihydrofuryl, imidazolyl, and pyrazolyl; wherein R 1 is selected from 5- and 6-membered heterocyclo, lower 10 cycloalkyl, lower cycloalkenyl and aryl selected from phenyl, biphenyl and naphthyl, wherein R 1 is optionally substituted at a substitutable position with one or more radicals selected from lower alkyl, lower haloalkyl, cyano, carboxyl, lower 15 alkoxycarbonyl, hydroxyl, lower hydroxyalkyl, lower haloalkoxy, amino, lower alkylamino, phenylamino, nitro, lower alkoxyalkyl, lower alkylsulfinyl, halo, lower alkoxy and lower alkylthio; wherein R 2 is amino; and wherein R 3 is a radical selected from 20 oxo, cyano, carboxyl, lower alkoxycarbonyl, lower carboxyalkyl, lower cyanoalkyl, halo, lower alkyl, lower alkyloxy, lower cycloalkyl, phenyl, lower haloalkyl, 5- or 6-membered heterocyclo, lower hydroxylalkyl, lower aralkyl, acyl, phenylcarbonyl, 25 lower alkoxyalkyl, 5- or 6-membered heteroaryloxy, aminocarbonyl, lower alkylaminocarbonyl, lower alkylamino, lower aminoalkyl, lower alkylaminoalkyl, phenyloxy, and lower aralkoxy; or a pharmaceutically-acceptable salt thereof. 30

4. The method of Claim 3 wherein A is selected from oxazolyl, isoxazolyl, imidazolyl, and pyrazolyl; wherein R 1 is phenyl optionally substituted at a substitutable position with one or 35 more radicals selected from methyl, ethyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 50 hexyl, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl, fluoromethyl, difluoroethyl, 5 difluoropropyl, dichloroethyl, dichloropropyl, cyano, carboxyl, methoxycarbonyl, hydroxyl, hydroxymethyl, trifluoromethoxy, amino, N methylamino, N,N-dimethylamino, N-ethylamino, N,N dipropylamino, N-butylamino, N-methyl-N-ethylamino, 10 phenylamino, nitro, methoxymethyl, methylsulfinyl, fluoro, chloro, bromo, methoxy, ethoxy, propoxy, n butoxy, pentoxy, and methylthio; wherein R 2 is amino; and wherein R 3 is a radical selected from oxo, cyano, carboxyl, methoxycarbonyl, 15 ethoxycarbonyl, carboxypropyl, carboxymethyl, carboxyethyl, cyanomethyl, fluoro, chloro, bromo, methyl, ethyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, 20 dichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl, fluoromethyl, difluoroethyl, difluoropropyl, dichioroethyl, dichloropropyl, methoxy, ethoxy, propoxy, n-butoxy, pentoxy, cyclohexyl, phenyl, pyridyl, thienyl, thiazolyl, 25 oxazolyl, furyl, pyrazinyl, hydroxylmethyl, hydroxylpropyl, benzyl, formyl, phenylcarbonyl, methoxymethyl, furylmethyloxy, aminocarbonyl, N methylaminocarbonyl, N,N-dimethylaminocarbonyl, N,N-dimethylamino, N-ethylamino, N,N-dipropylamino, 30 N-butylamino, N-methyl-N-ethylamino, aminomethyl, N,N-dimethylaminomethyl, N-methyl-N ethylaminomethyl, benzyloxy, and phenyloxy; or a pharmaceutically-acceptable salt thereof. 35

5. The method of Claim 1 wherein the compound is selected from compounds, and their pharmaceutically SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 51 acceptable salts, of the group consisting of RS-57067 000, JT-522, 3-(3,4-difluorophenyl)-4-(4-methylsulfonylphenyl) 5 2-(5H)-furanone; 3-phenyl-4-4-methylsulfonylphenyl)-2-(5H)-furanone; 4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H pyrazol-1-yl]benzenesulfonamide; 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H 10 pyrazol-1-yllbenzenesulfonamide; 4-[5-(3-fluoro-4-methoxyphenyl)-3-(difluoromethyl) 1H-pyrazol-1-yl]benzenesulfonamide; 3-[l-[4-(methylsulfonyl)phenyl]-4-trifluoromethyl 1H-imidazol-2-yl]pyridine; 15 2-methyl-5-[1-[4-(methylsulfonyl)phenyl]-4 trifluoromethyl-1H-imidazol-2-yl]pyridine; 4-[2-(5-methylpyridin-3-yl)-4-(trifluoromethyl)-1H imidazol-1-yl]benzenesulfonamide; 4-[5-methyl-3-phenylisoxazol-4 20 yl]benzenesulfonamide; 4-[5-hydroxyethyl-3-phenylisoxazol-4 yl]benzenesulfonamide; [2-trifluoromethyl-5-(3,4-difluorophenyl)-4 oxazolyl]benzenesulfonamide; 25 4-[2-methyl-4-phenyl-5-oxazolyl]benzenesulfonamide; and 4-[5-(3-fluoro-4-methoxyphenyl-2-trifluoromethyl) 4-oxazolyl]benzenesulfonamide. 30

6. A method of maintaining circulation through fetal ductus arteriosus during treatment or prevention of preterm labor in a subject in need of such treatment of prevention, said method comprising treating the subject with a therapeutically-effective amount of a 35 compound of Formula II: SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 52 R 6 R 5 0 0 S\N N/4 / La %" 4 HN N R 2 wherein R 4 is selected from hydrido, alkyl, 5 haloalkyl, alkoxycarbonyl, cyano, cyanoalkyl, carboxyl, aminocarbonyl, alkylaminocarbonyl, cycloalkylaminocarbonyl, arylaminocarbonyl, carboxyalkylaminocarbonyl, carboxyalkyl, aralkoxycarbonylalkylaminocarbonyl, aminocarbonylalkyl, 10 alkoxycarbonylcyanoalkenyl and hydroxyalkyl; wherein R 5 is selected from hydrido, alkyl, cyano, hydroxyalkyl, cycloalkyl, alkylsulfonyl and halo; and wherein R 6 is selected from aralkenyl, aryl, cycloalkyl, cycloalkenyl and heterocyclic; wherein R 4 is 15 optionally substituted at a substitutable position with one or more radicals selected from halo, alkylthio, alkylsulfonyl, cyano, nitro, haloalkyl, alkyl, hydroxyl, alkenyl, hydroxyalkyl, carboxyl, cycloalkyl, alkylamino, dialkylamino, alkoxycarbonyl, aminocarbonyl, alkoxy, 20 haloalkoxy, sulfamyl, heterocyclic and amino; or a pharmaceutically-acceptable salt or derivative thereof.

7. The method of Claim 6 wherein R 4 is selected 25 from lower haloalkyl; wherein R 5 is hydrido; and wherein R 6 is phenyl optionally substituted at a substitutable position with one or more radicals selected from halo, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 53 lower alkyl, and lower alkoxy; or a pharmaceutically acceptable salt or derivative thereof.

8. The method of Claim 7 wherein the compound is 5 selected from compounds, and their pharmaceutically acceptable salts, of the group consisting of 4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-l yl]benzenesulfonamide; 10 4-[5-phenyl-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-fluorophenyl)-3-(trifluoromethyl)-lH-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 15 yl]benzenesulfonamide; 4-[S-(4-chlorophenyl)-3-(difluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 20 4-[3-(difluoromethyl)-5-(4-methylphenyl)-lH-pyrazol-1 yl]benzenesulfonamide; 4-[3-(difluoromethyl)-5-phenyl-lH-pyrazol-1 yl]benzenesulfonamide; 4-[3-(difluoromethyl)-5-(4-methoxyphenyl)-lH-pyrazol-l 25 yl]benzenesulfonamide; 4-[3-(difluoromethyl)-5-(3-fluoro-4-methoxyphenyl)-1H pyrazol-1-yl]benzenesulfonamide; and 4-[5-(3-fluoro-4-methoxyphenyl)-3-(trifluoromethyl)-1H pyrazol-1-yllbenzenesulfonamide. 30 SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 54

9. The method of Claim 7 wherein the compound is 4 [5-(4-methyiphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide, or a pharmaceutically-acceptable salt thereof. 5

10. The method of Claim 7 wherein the compound is 4-[S-(4-chlorophenyl)-3-(difluoromethyl)-1H-pyrazol-1 yl benzenesulfonamide, or a pharmaceutically-acceptable salt thereof. 10

11. The method of Claim 7 where the compound is 4 [5-(3-fluoro-4-methoxyphenyl)-3-(difluoromethyl)-lH pyrazol-1-yl]benzenesulfonamide, or a pharmaceutically acceptable salt thereof. 15

12. A method of treating or preventing preterm laborin a subject in need of such treatment of prevention, said method comprising treating the subject with a therapeutically-effective amount of a compound of 20 Formula I: R R3I C - A R3 wherein A is selected from oxazolyl, isoxazolyl, 25 dihydrofuryl, imidazolyl, and pyrazolyl; wherein Rl is selected from 5- and 6-membered heterocyclo, lower cycloalkyl, lower cycloalkenyl and aryl selected from phenyl, biphenyl and naphthyl, wherein R 1 is optionally substituted at a 30 substitutable position with one or more radicals selected from lower alkyl, lower haloalkyl, cyano, carboxyl, lower alkoxycarbonyl, hydroxyl, lower hydroxyalkyl, lower haloalkoxy, amino, lower alkylamino, phenylamino, nitro, lower alkoxyalkyl, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 55 lower alkylsulfinyl, halo, lower alkoxy and lower alkylthio; wherein R 2 is amino; and wherein R 3 is a radical selected from oxo, cyano, carboxyl, lower alkoxycarbonyl, lower carboxyalkyl, lower 5 cyanoalkyl, halo, lower alkyl, lower alkyloxy, lower cycloalkyl, phenyl, lower haloalkyl, 5- or 6 membered heterocyclo, lower hydroxylalkyl, lower aralkyl, acyl, phenylcarbonyl, lower alkoxyalkyl, 5- or 6-membered heteroaryloxy, aminocarbonyl, 10 lower alkylaminocarbonyl, lower alkylamino, lower aminoalkyl, lower alkylaminoalkyl, phenyloxy, and lower aralkoxy; or a pharmaceutically-acceptable salt thereof. 15

13. The method of Claim 12 wherein A is selected from oxazolyl, isoxazolyl, imidazolyl, and pyrazolyl; wherein R 1 is phenyl optionally substituted at a substitutable position with one or more radicals selected from methyl, ethyl, 20 isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl, fluoromethyl, difluoroethyl, 25 difluoropropyl, dichloroethyl, dichloropropyl, cyano, carboxyl, methoxycarbonyl, hydroxyl, hydroxymethyl, trifluoromethoxy, amino, N methylamino, N,N-dimethylamino, N-ethylamino, N,N dipropylamino, N-butylamino, N-methyl-N-ethylamino, 30 phenylamino, nitro, methoxymethyl, methylsulfinyl, fluoro, chloro, bromo, methoxy, ethoxy, propoxy, n butoxy, pentoxy, and methylthio; wherein R 2 is amino; and wherein R 3 is a radical selected from oxo, cyano, carboxyl, methoxycarbonyl, 35 ethoxycarbonyl, carboxypropyl, carboxymethyl, carboxyethyl, cyanomethyl, fluoro, chloro, bromo, SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 56 methyl, ethyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, pentafluoroethyl, 5 heptafluoropropyl, fluoromethyl, difluoroethyl, difluoropropyl, dichloroethyl, dichloropropyl, methoxy, ethoxy, propoxy, n-butoxy, pentoxy, cyclohexyl, phenyl, pyridyl, thienyl, thiazolyl, oxazolyl, furyl, pyrazinyl, hydroxylmethyl, 10 hydroxylpropyl, benzyl, formyl, phenylcarbonyl, methoxymethyl, furylmethyloxy, aminocarbonyl, N methylaminocarbonyl, N,N-dimethylaminocarbonyl, N,N-dimethylamino, N-ethylamino, N,N-dipropylamino, N-butylamino, N-methyl-N-ethylamino, aminomethyl, 15 N,N-dimethylaminomethyl, N-methyl-N ethylaminomethyl, benzyloxy, and phenyloxy; or a pharmaceutically-acceptable salt thereof.

14. The method of Claim 12 wherein the compound is 20 selected from compounds, and their pharmaceutically acceptable salts, of the group consisting of RS-57067 000, JT-522, 3-(3,4-difluorophenyl)-4-(4-methylsulfonylphenyl) 25 2-(5H)-furanone; 3-phenyl-4-4-methylsulfonylphenyl)-2-(5H)-furanone; 4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H pyrazol-1-yllbenzenesulfonamide; 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H 30 pyrazol-1-yl]benzenesulfonamide; 4-[5-(3-fluoro-4-methoxyphenyl)-3-(difluoromethyl) 1H-pyrazol-1-yl]benzenesulfonamide; 3-[1-[4-(methylsulfonyl)phenyl]-4-trifluoromethyl 1H-imidazol-2-yl]pyridine; 35 2-methyl-5-[1-[4-(methylsulfonyl)phenyl]-4 trifluoromethyl-1H-imidazol-2-yl]pyridine; SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCTIUS98/22246 57 4-[2-(5-methylpyridin-3-yl)-4-(trifluoromethyl)-1H imidazol-1-yl]benzenesulfonamide; 4-[5-methyl-3-phenylisoxazol-4 yl]benzenesulfonamide; 5 4-[5-hydroxyethyl-3-phenylisoxazol-4 yl]benzenesulfonamide; [2-trifluoromethyl-5-(3,4-difluorophenyl)-4 oxazolyl]benzenesulfonamide; 4-[2-methyl-4-phenyl-5-oxazolyl]benzenesulfonamide; 10 and 4-[5-(3-fluoro-4-methoxyphenyl-2-trifluoromethyl) 4-oxazolyl]benzenesulfonamide.

15. A method of treating or preventing preterm 15 labor in a subject in need of such treatment of prevention, said method comprising treating the subject with a therapeutically-effective amount of a compound of Formula II: R6 5 S N N1II 20 2 wherein R 4 is selected from hydrido, alkyl, haloalkyl, alkoxycarbonyl, cyano, cyanoalkyl, carboxyl, aminocarbonyl, alkylaminocarbonyl, 25 cycloalkylaminocarbonyl, arylaminocarbonyl, carboxyalkylaminocarbonyl, carboxyalkyl, aralkoxycarbonylalkylaminocarbonyl, aminocarbonylalkyl, alkoxycarbonylcyanoalkenyl and hydroxyalkyl; wherein R 5 is selected from hydrido, alkyl, cyano, 30 hydroxyalkyl, cycloalkyl, alkylsulfonyl and halo; and SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 58 wherein R 6 is selected from aralkenyl, aryl, cycloalkyl, cycloalkenyl and heterocyclic; wherein R 4 is optionally substituted at a substitutable position with one or more radicals selected from halo, alkylthio, 5 alkylsulfonyl, cyano, nitro, haloalkyl, alkyl, hydroxyl, alkenyl, hydroxyalkyl, carboxyl, cycloalkyl, alkylamino, dialkylamino, alkoxycarbonyl, aminocarbonyl, alkoxy, haloalkoxy, sulfamyl, heterocyclic and amino; or a pharmaceutically-acceptable salt or 10 derivative thereof.

16. The method of Claim 15 wherein R 4 is selected from lower haloalkyl; wherein R 5 is hydrido; and wherein R 6 is phenyl optionally substituted at a substitutable 15 position with one or more radicals selected from halo, lower alkyl, and lower alkoxy; or a pharmaceutically acceptable salt or derivative thereof.

17. The method of Claim 15 wherein the compound is 20 selected from compounds, and their pharmaceutically acceptable salts, of the group consisting of 4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 25 4-[5-phenyl-3-(trifluoromethyl)-lH-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-fluorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yllbenzenesulfonamide; 4-[5-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 30 yl]benzenesulfonamide; SUBSTITUTE SHEET (RULE 26) WO 99/22720 PCT/US98/22246 59 4-[5-(4-chlorophenyl)-3-(difluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide; 5 4-[3-(difluoromethyl)-5-(4-methylphenyl)-lH-pyrazol-1 yljbenzenesulfonamide; 4-[3-(difluoromethyl)-5-phenyl-1H-pyrazol-1 yl]benzenesulfonamide; 4-[3-(difluoromethyl)-5-(4-methoxyphenyl)-1H-pyrazol-l 10 yl]benzenesulfonamide; 4-[3-(difluoromethyl)-5-(3-fluoro-4-methoxyphenyl)-1H pyrazol-1-yllbenzenesulfonamide; and 4-[5-(3-fluoro-4-methoxyphenyl)-3-(trifluoromethyl)-1H pyrazol-1-yl]benzenesulfonamide. 15

18. The method of Claim 15 wherein the compound is 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-l yl]benzenesulfonamide, or a pharmaceutically-acceptable salt thereof. 20

19. The method of Claim 15 wherein the compound is 4-[5-(4-chlorophenyl)-3-(difluoromethyl)-lH-pyrazol-l yl]benzenesulfonamide, or a pharmaceutically-acceptable salt thereof. 25

20. The method of Claim 15 where the compound is 4 [5-(3-fluoro-4-methoxyphenyl)-3-(difluoromethyl)-1H pyrazol-1-yllbenzenesulfonamide, or a pharmaceutically acceptable SUBSTITUTE SHEET (RULE 26)