Amberlyst-15-Catalyzed Synthesis of 2-Substituted 1,3-Benzazoles in Water under Ultrasound

A clean and general method has been developed for the synthesis of benzothiazole, benzoxazole, and benzimidazoles using Amberlyst-15 as a recyclable catalyst under ultrasound irradiation in water. The methodology is operationally simple, free from the use of hazardous organic solvents, and does not require the use of inert or anhydrous atmosphere. A number of 1,3-benzazole derivatives were prepared in good to excellent yields by using this methodology. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) for the following free supplemental resource: Full experimental and spectral details.]