Synthesis, analgesic and anti-inflammatory activities of some 1-acyl/aracyl-5-aminopyrazole derivatives.

A series of 1-acyl/aracyl-3, 4-disubstituted-5-aminopyrazoles (IV) were synthesized by the reaction of 1-acyl/aracylhydrazines (I) with an appropriately substituted ketenedithioacetal (II/III). Compounds IV were tested for their analgesic activity by rat caudal immersion test and anti-inflammatory activity by carrageenin induced edema in rat paw test. 1-Benzoyl-3-mercapto-4-carboxamido-5-aminopyrazole (IVk) proved to be the most active compound of the series in both tests.