Ultrasound-promoted greener synthesis of benzoheterocycle derivatives catalyzed by nanocrystalline copper(II) oxide

CuO nanoparticles provide an efficient, economic, and novel method for the synthesis of quinoxaline, benzoxazine, and benzothiazine under ultrasonic irradiation. The protocol offers advantages in terms of higher yields, short reaction times, and mild reaction conditions, with reusability of the catalyst.