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

Abstract

Article history:Received Received in revised form Accepted Available online 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. 1. Introduction Ionic liquids, a class of low-melting chemical compounds that include an organic cation and an organic/inorganic anion, are known as molten salts. Generally, the cation is an organic species containing heteroatoms such as phosphorous, sulfur, and nitrogen and the anion may be varied as chloride, bromide, iodide, tetrafluoroborate, hexafluorophosphate, nitrate, and acetate [1]. Because of their unique properties such as non-volatility, non-flammability, safety, recyclability and ability to dissolve a wide range of compounds, a variety of ionic liquids have been used in organic synthesis [2-6].In recent years, synthesis of