Iodine-catalyzed C-H functionalization of methylhetarenes: One-pot synthesis and cytotoxic evaluation of heteroarenyl-benzimidazoles and benzothiazole.

An efficient one-pot synthetic procedure has been developed for the preparation of heteroarenyl-benzimidazoles via oxidative C-H functionalization with o-phenylenediamine using I-DMSO in open air from easily available starting materials. Based on a logical plan a spectrum of multi fundamental reactions like iodination, Kornblum oxidation and amination were brought into one-pot. By using this simple method a library of heteroarenyl-benzimidazoles derivatives (3a-t and 5a-g) and heteroarenyl-benzothiazole (3u) have been synthesized in good to excellent yield and screened for their cytotoxicity against a group of four human cancer cell lines. Among them 3h, 3q and 5b showed significant cytotoxic activities with an IC of 1.69, 1.62 and 2.81µM respectively against lung cancer (A549) cell line.