Efficient propylphosphonic anhydride (®T3P) mediated synthesis of benzothiazoles, benzoxazoles and benzimidazoles

Propylphosphonic anhydride (®T3P) promotes cyclization of o-aminobenzenethiol, o-aminophenol, and o-phenylenediamine with carboxylic acids under microwave irradiation. The one-pot procedure is efficient and allows short reaction times, easy workup, and good yields. Thus, we describe here a method for quick preparation of benzothiazoles, benzoxazoles and benzimidazoles.