Design, Synthesis and Biological Evaluation of New Imidazo[2,1-b] Thiazole Derivatives as Selective COX-2 Inhibitors

A new series of imidazo [2,1-b] thiazole analogs containing a methyl sulfonyl cox-2 pharmacophore was synthesized and evaluated for their cox-2 inhibitory activity. according to in-vitro cox- 1/cox-2 inhibition data, all compounds (6a-g) were selective inhibitors of cox-2 isoenzyme with ic_50 values in the highly potent 0.08-0.16 µm range. these results indicated that both potency and selectivity of cox-2 inhibitory activity were affected by the type and size of amine on c-5 of imidazo [2,1-b] thiazole ring. our data identified n,n-dimethyl-1-(6-(4-(methylsulfonyl) phenyl) imidazo [2,1-b]thiazol-5-yl) methanamine (6a) as a potent and selective cox-2 inhibitor (ic_50 cox-1 >100 µm; ic_50 cox-2 = 0.08 µm; selectivity index = 313.7). our results indicated that both potency and selectivity of cox-2 inhibitory activity were affected by the type and size of amine on c-5 of imidazo [2,1-b] thiazole ring.