Synthesis of Benzothiazoles and Benzoxazoles from Thiobenzamides

Significance

An iodine-initiated synthesis of benz­oxazoles and benzothiazoles from thiobenz­amides is reported. Electrophilic substitution mechanisms, initiated by S-iodination, are proposed to rationalize the reaction routes. Interestingly, the bulky isopropyl group and the electron-withdrawing tosyl group do not prevent the ortho oxygen from attacking the sulfenyl iodide; however, the yields are comparatively low and the scope requires more exploration.