Synthesis and in vitro cytotoxic evaluation of some thiazolylbenzimidazole derivatives

► Reported thiazolylbenzimidazole-4,7-diones are potentially toxic both to tumor cell lines and to normal counterparts. ► Novel thiazolylbenzimidazole compounds without quinone moiety were designed and synthesized. ► To increase the antitumor activity, efforts were exerted on the structure modification of the thiazole ring. ► Most compounds showed good antitumor activities, and compound 11b displayed remarkable in vitro anticancer activity comparable to taxol.