An efficient synthetic route towards novel thienobenzothiazoles, thienobenzothiazepines, and thienobenzothiazines

Efficient methods for the synthesis of novel nitrogen- and sulfur-containing heterocycles, annulated in the 4,5-position of benzothiophene, are described. Applying the Herz reaction, 3H-thienobenzodithiazole 2-oxide was prepared. This compound served as o-aminothiophenol precursor in the synthesis of a variety of thienobenzothiazoles, thienobenzothiazepines, thienobenzothiazines, and thienothiadiazole.