Synthesis and Anti‐cancer Activity of 1,3,4‐Thiadiazole and 1,3‐Thiazole Derivatives Having 1,3,4‐Oxadiazole Moiety

Reaction of 1,3,4‐oxadiazolyl‐phenylthiourea 3 with hydrazonoyl halides gave the corresponding 1,3,4‐oxadiazolylimino‐1,3,4‐thiadiazoles. Also, treatment of 3 with ethyl chloroacetate and α‐haloketones afforded the corresponding thiazolidinone and thiazole derivatives, respectively. The structures of the synthesized products were confirmed by spectral data. Ten compounds were evaluated for their anti‐cancer activity against the colon carcinoma cell line (HCT‐116). The results revealed that 1,3,4‐thiadiazole derivatives 13d and 19c (IC 50 = 0.73 and 0.86 µg/mL, respectively) have promising antitumor activity against colon carcinoma (HCT‐116), and most of the tested compounds showed moderate anti‐cancer activity.