Synthesis of new imidazolyl acetic acid derivatives with anti-inflammatory and analgesic activities.

We synthesized 2-(4-(4-fluorobenzylidene)-2-(4-fluorophenyl) 5-oxo-4,5-dihydroimidazol-1-yl) acetic acid 3. Chlorination afforded the chloro derivative 4, which reacted with different amines and hydrazine to afford compounds 5-8. Pyrazole, pyrazolone, and thiazolidinone derivatives were also synthesized from Imidazol-1-ylacetic acid hydrazide 8 to give compounds 9-12. Compounds were then evaluated for their anti-inflammatory activity against carrageenan-induced rat paw edema and their analgesic activity using the writhing test in albino mice. Compounds 5, 9, 10, 12 exhibited maximum anti-inflammatory activity, and all the compounds inhibited writhing, with 10 and 12 being two times more effective than the reference standard.