Iodine a simple, effective and inexpensive catalyst for the synthesis of substituted coumarins

Molecular iodine is developed as an efficient catalyst in the von Pechmann condensation of phenols with beta-ketoesters which leads to the formation of coumarin derivaties in excellent yields when carried out under microwave irradiation in a Prolabo Synthwave Microwave Reactor. The reaction also proceeds when carried out in the absence of solvent and at room temperature in acetonitrile.