ONE-POT SYNTHESIS OF BENZOTHIAZOL-2-AMINES BY CYCLIZATION OF THE ADDUCTS BETWEEN 2-IODOPHENYL ISOTHIOCYANATES AND AMINES UNDER METAL-FREE CONDITIONS

摘要

A convenient one-pot procedure for the preparation of N-substituted and N,N-disubstituted benzothiazol-2-amines under metal-free conditions has been developed, which employs the reaction of 2-iodophenyl isothiocyanates with primary and secondary amines followed by cyclization of the resulting thiourea precursors on treatment with triethylamine under relatively mild reaction conditions (< 70 °C). The reactions using diamines, such as ethylenediamines or trimethylenediamine, under similar conditions, albeit at higher temperature (130 °-C), have proved to enable us to obtain N,N'-bis(benzothiazol-2-yl)ethane(or propane)diamines.