Synthesis of Novel Thiazole Derivatives as Analgesic Agents

Thiazoles have a long history of having number of pharmacological activities such as anti-microbial, analgesic and anti-inflammatory activities. Pyrazoles shows promising anti-microbial, analgesic and anti-inflammatory activities. In the present study, novel thiazoles (8a - 8j) were synthesized by incorporation of pyrazole moiety at 2^nd position of 2-hydrazinyl-N-(4-phenylthiazol-2-yl) acetamide (5) by treating with chalcones (7a-7j). The chemical structures of the synthesized compounds were confirmed by means of IR, ¹H-NMR, Mass spectral and Elemental analysis. All the spectral data were consistent with the assigned structure. The synthesized compounds were investigated for analgesic activity by tail immersion method in mice. All the synthesized compounds exhibited mild to good analgesic activities. Among the synthesized compounds, 2-(5-(4-dimethylaminophenyl)-3-phenyl-4,5-dihydropyrazol-1-yl)-N-(4- phenylthiazol-2-yl) acetamide (8c) and 2-(5-(4-methylphenyl)-3-phenyl-4,5-dihydropyrazol-1-yl)-N-(4-phenylthiazol- 2-yl) acetamide (8e) exhibited highest analgesic activity.