Synthesis and Antiinflammatory Activity of Newer Pyrazolinylbenzidines and Isoxazolinylbenzidines

In an effort to search for more active antiinflammatory agent, a series of pyrazolinylbenzidines and isoxazolylbenzidines was designed, synthesized, and screened for their potential as novel orally inflammation inhibitors. Compounds 4,4'-bis-(1"-acetyl-5"-substitutedaryl-2"-pyrazolin-3"-yl)benzidines (8-13) and 4,4'-bis-(2"-substitutedaryl-isoxazolin-4'-yl)benzidines (14-19) have been synthesized from 4,4'-bis-(substituted benzylidenyl-acetyl)benzidines (2-7). The structures of the products have been delineated by spectral and elemental analysis. Compounds 2-19 evaluated for antiinflammatory activity and acute toxicity and results are reported. The compound 4,4'-bis-[1"-acetyl-5"-(p-methoxyphenyl)-2"-pyrazolin-3'-yl)benzidine (9) showed more potent and dose-dependent antiinflammatory activity in comparison to reference drug.