A green approach for the synthesis of 2-substituted benzoxazoles and benzothiazoles coupling/cyclization reactions.

We have developed the green method for the synthesis of benzoxazoles and benzothiazoles with moderate to good yields using imidazolium chlorozincate (II) ionic liquid supported into FeO nanoparticles (LAIL@MNP) under solvent-free sonication. The reaction was performed under mild conditions and only produced water as a sole byproduct. The reactions under solvent-free sonication showed advantages of faster reaction rate (30 min) and high yields of the products (up to 90%). Moreover, the LAIL@MNP material was easily separated from the reaction mixture and can be recycled for five consecutive runs with a slight decrease in its catalytic performance (from 82 to 73%).