Synthesis and application of polyvinylimidazole-based Brønsted acidic ionic liquid grafted silica as an efficient heterogeneous catalyst in the preparation of quinoxaline derivatives

Two types of polymer-grafted silica based on polyvinylimidazole Brønsted acidic ionic liquids were prepared and used as new heterogeneous catalysts for the preparation of pharmaceutically important quinoxaline derivatives. These catalysts were characterized by thermogravimetric analysis, FT-IR spectroscopy, and titration. They could be recycled without considerable loss in their catalytic activity. High efficiency of the catalysts along with short reaction times, high yields, easy purification, recyclability, and simple procedure are among the advantages of these catalytic systems.