Diaminobenzobisthiazoles and related compounds

Abstract

In the preparation of benzobisthiazoles from m- and p-phenylenediamines by thiocyanation or by ring closure of derived thioureas the linear tricyclic compound is usually the major or the only product. 3,6-Diamino-1,2-phenylene di(hydrogen thiosulphate)(the so-called p-phenylenediamino-2,5-bisthiosulphuric acid) is the 2,3-isomer and correction is required to structures assigned to its derivatives, e.g., the diaminophenylenedithiol, the bisdiazosulphide, and certain benzobisthiazoles. Formation of fused thiazole rings in derivatives of 2-naphthylamine and 6-aminoquinoline occurs in the 1- and 5-positions respectively.