Highly Efficient Ultrasound Promoted Synthesis of 2-phenylquinoxaline in Glycerol- Water

Abstract

Quinoxalines show diversified applications in the field of medicinal chemistry. Therefore, we have designed a highly efficient, environmentally benign and one-pot protocol for the synthesis of 2-phenylquinoxaline from the reaction of Acetophenone, N-bromosuccinimide and 1,2-phenylenediamine under ultrasound irradiation in glycerol-water. We observed that, although the reaction efficiently completed in all of these solvents, the use of glycerol-water with different ratios gives consistently higher yields (89-94%) and decreases reaction times. The main advantages of this protocol are that it is a green method, avoids the use of toxic catalysts and volatile organic medium and the product is obtained with excellent yield.