COX-2-IN-18 (Compound 3) is a potent inhibitor of COX-2. COX-2-IN-18 possesses good COX-2 inhibitory activity ( IC 50 = 0.775 μM) compared to the reference agent, Celecoxib ( IC 50 = 0.153 μM). COX-2-IN-18 has the potential for the research of cancer diseases.