A series of sulfonamide-containing 1,5-diarylpyrazole derivatives were prepared and evaluated for their ability to block cyclooxygenase-2 (COX-2) in vitro and in vivo. Extensive structure-activity relationship (SAR) work was carried out within this series, and a number of potent and selective inhibitors of COX-2 were identified. Since an early structural lead (1f, SC-236) exhibited an unacceptably long plasma half-life, a number of pyrazole analogs containing potential metabolic sites were evaluated further in vivo in an effort to identify compounds with acceptable pharmacokinetic profiles. This work led to the identification of 1i (4-[5-(4-methylphenyl)-3-(trifluoromethyl)- H-pyrazol-1-yl]benzenesulfonamide, SC-58635, celecoxib), which is currently in phase III clinical trials for the treatment of rheumatoid arthritis and osteoarthritis.

Our previous reports have highlighted the first-generation leukotriene B4 (LTB4) receptor antagonist SC-41930 (7-[3-(4-acetyl-3-methoxy-2-propylphenoxy)propoxy]3,4- dihydro-8-propyl-2H-1-benzopyran-2-carboxylic acid) which has potent oral, topical, and intracolonic activity in various animal models of inflammation. Extensive structure-activity relationship studies, in which a series of heterocyclic replacements for the methyl ketone functional group of SC-41930 was explored, identified SC-50605 (7-[3-[2-(cyclopropylmethyl)-3-methoxy-4- (4-thiazolyl)phenoxy]propoxy]-3,4-dihydro-8-propyl-2H-1-benzopyran-2- carboxylic acid) as an optimized analog within a series of thiazoles. SC-50605 was found to be significantly more potent than SC-41930 in LTB4 receptor binding, chemotaxis, and degranulation assays. It also displayed very good activity in animal models of colitis and epidermal inflammation by oral, topical, intravenous, and intracolonic routes of administration. The resolved enantiomers of SC-50605 were obtained by chiral chromatography and both demonstrated good in vitro and in vivo activity. The (+)-isomer (SC-52798) is currently being evaluated as a potential clinical candidate for psoriasis and ulcerative colitis therapy.