Design, synthesis and biological evaluation of some novel benzylidene-2-(4-phenylthiazol-2-yl) hydrazines as potential anti-inflammatory agents

A series of substituted benzylidene-2-(4-phenylthiazol-2-yl) hydrazines (2a-q) have been synthesized, characterized and evaluated for their anti-inflammatory activity by carrageenin-induced hind paw edema (acute inflammation) and cotton pellet granuloma (chronic inflammation) methods in rats. In carrageenin-induced hind paw edema method, compounds 2a, 2b, 2c, 2d, 2h, 2k and 2p at a dose of 20 mg kg(-1) body weight, p.o. showed excellent inhibitions (51.80-86.74 %) in between 1 and 4 h. Similarly, in cotton pellet granuloma method, compounds 2a, 2b, 2c, 2d, 2h, 2k and 2p at a dose of 20 mg kg(-1) body weight, p.o. inhibited the granuloma formation (71.71-90.19 % inhibition) which was comparable to that of standard drug, ibuprofen (90.36 % inhibition of paw volume at 3 h and 94.02 % inhibition of granuloma formation). Structure activity relationship studies showed excellent activity of the compounds containing electron withdrawing group (fluoro, chloro, bromo or nitro) in phenyl ring at C2 and/or C4 position of thiazole ring.