An environmentally benign and efficient synthesis of substituted benzothiazole-2-thiols, benzoxazole-2-thiols, and benzimidazoline-2-thiones in water

An efficient and practical method for the one-step synthesis of benzothiazole-2-thiols, benzoxazole-2-thiols and benzimidazoline-2-thiones by cyclization of 2-aminothiophenols, 2-aminophenols, and 1,2-phenylenediamines with tetramethylthiuram disulfide (TMTD) in water was described. The features of this method include metal/ligand-free, excellent yield, short reaction time and broad substrate scope. The method provides a facile and convenient preparation of some potentially biologically active compounds.