2-Amino-5-sulfanyl-1,3,4-thiadiazoles: a new series of selective cyclooxygenase-2 inhibitors.

A new series of cyclooxygenase-2 inhibitors with 2-amino-5-sulfanyl-1,3,4-thiadiazole as the central scaffold unit has been synthesized. The newly synthesized compounds were characterized by analytical and spectral methods. Compounds were screened for cyclooxygenase inhibitory activity by the colorimetric COX (ovine) inhibitor screening assay, anti-inflammatory activity by the carrageenean induced rat paw oedema test and analgesic activity by the tail flick method. Some compounds exhibited significant biological activity.