Pectin as a natural biopolymer catalyst promoted green synthesis of dihydropyrano[2,3-c]pyrazole derivatives in aqueous ethanol media

A green and one-pot protocol for the facile synthesis of biologically important dihydropyrano[2,3-c]pyrazole derivatives has been developed. In this method pectin has been utilized as a natural biopolymer catalyst to get quick access to the dihydropyrano[2,3-c]pyrazole derivatives in aqueous ethanol media and short reaction times. The main advantages of this method are the operational simplicity, reduced reaction time, high yield of the products, avoidance of any hazardous organic solvent, toxic catalyst, tedious purification step, convenient work up procedure and employment of natural, highly efficient and readily available catalyst. All these factors make the present method economical, green and sustainable.