Synthesis of benzothiazoles catalyzed by [Bmim]PF6 ionic liquid in solvent-free condition

A novel, simple and efficient method for the synthesis of benzothiazoles in solvent-free conditions has been developed from 2-aminophenthiols and aromatic aldehydes, using ionic liquid [Bmim]PF6 as a catalyst. It is noteworthy that [Bmim]PF6 acts as both the catalyst and solvent, and no additional organic solvents are required in this reaction. In addition, this reaction has a wide range of substrate scope and a series of benzothiazoles are smoothly synthesized with good to excellent yields.