One pot synthesis of 2-substituted thiobenzoazoles containing α-sulfenylated aromatic ketones under transition metal-free conditions

An efficient synthesis of 2-substituted thiobenzoazoles in pot manner was reported. Thus, tetramethylthiuram disulfide (TMTD) reacted with 2-aminothiophenol, 2-aminophenol, or 1,2-phenylenediamine to form 2-mercaptobenzo heterocycles through cyclization, and the subsequent C-S bonding with 2-bromoacetophenones gave the desired 2-substituted thiobenzoazoles containing & alpha;-sulfenylated aromatic ketones smoothly. The method features transition metal-free, simple operation, mild conditions, short reaction time, and good yields, showing potential synthetic value for the synthesis of a variety of biological or pharmaceutically active compounds.