Experimental Section" Preparation of 2-Substituted Benzothiazoles. The General Procedure is Illustrated with 2-Methylbenzothiazole (la). A 4.5-g solution of P z @ ~ / CH ~ SO ~ H (1/10, w/w)lo was treated sequentially with 2-aminothiopheno1(3.0 mmol, 376 mg) and acetic acid (3.0 mmol, 180 mg). The resulting solution was stoppered and magnetically stirred at 25 (1 h) and 70 "C (10 h). After cooling, the solution was slowly added to ca. 50--75 mL of ...
