Electrochemical regioselective methylthiolation of imidazo[2,1-b]thiazoles with DMSO

With DMSO both as the source of -SMe unit and solvent, an efficient and green electrochemical methylthiolation reaction of imidazo[2,1-b]thiazoles was developed. The transformation was performed at room temperature in 8 h under external transition metal- and oxidant-free condition. Moreover, the 2,3-dihydroimidazo[2,1-b]thiazoles and 2-phenylbenzo[d]imidazo[2,1-b]thiazole also proceeded smoothly. This strategy provides C-5 methylthiolation products with broad scope in 73-91% yields.