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

Introduction: Quinoxalines show diversified applications in the field of medicinal chemistry. Materials and Methods: 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. Results and Discussion: 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. Conclusion: 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.