Synthesis, biological evaluation and molecular modeling of dihydro-pyrazolyl-thiazolinone derivatives as potential COX-2 inhibitors

Abstract A series of dihydro-pyrazolyl-thiazolinone derivatives ( 5a – 5t ) have been synthesized and their biological activities were also evaluated as potential cyclooxygenase-2 (COX-2) inhibitors. Among these compounds, compound 2-(3-(3,4-dimethylphenyl)-5-phenyl-4,5-dihydro-1 H -pyrazol-1-yl)thiazol-4(5 H )-one ( 5a) displayed the most potent COX-2 inhibitory activity with IC 50 of 0.5 μM, but weak to COX-1. Docking simulation was performed to position compound 5a into the COX-2 active site to determine the probable binding model. Based on the preliminary results, compound 5a with potent inhibitory activity and low toxicity would be a potential and selective anti-cyclooxygenase-2 agent.