One-Pot Synthesis of Substituted Coumarins Catalyzed by Silica Gel Supported Sulfuric Acid Under Solvent-Free Conditions

Abstract

A remarkable acceleration in the synthesis of substituted coumarins via Pechmann reaction catalyzed by silica gel supported sulfuric acid (H2SO4/silica gel) at 120 °C in high yields under solvent-free reaction condition with short re- action times is described. This methodology offers momentous improvements over various options for the synthesis of coumarins with regard to yield of products, simplicity in operation and green aspects by avoiding toxic catalysts and sol- vents.