An efficient and facile synthesis of the coumarin and ester derivatives using sulfonated polyionic liquid as a highly active heterogeneous catalyst

In this research, a novel solid acid catalyst, sulfonic acid immobilized on poly ionic liquid (SPIL), was described. The final catalyst, SPIL, which was simply synthesized and characterized by fourier transform infrared spectroscopy and thermo‐gravimetric analysis, was found to be an efficient and environmentally benign solid acid for the Pechmann and esterification reactions under the solvent free conditions. The studies showed that the catalyst could be easily recovered and reused at least three reaction cycles without any significant loss in catalytic activity and efficiency.