Co3O4–CNT nanocomposites: a powerful, reusable, and stable catalyst for sonochemical synthesis of polyhydroquinolines

Abstract

A novel and facile sonochemical synthesis of polyhydroquinolines is catalyzed by Co₃O₄–CNT nanocomposites from aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in ethanol medium. This highly effective catalytic system provides a green strategy to generate a variety of polyhydroquinolines under sonic conditions. Moreover, an efficient comparison between the conventional heating and sonication techniques for the synthesis of polyhydroquinoline heterocycles was made. Compared to the heating methodology, the ultrasound procedure showed several advantages including excellent yields, shorter reaction times and environmentally benign milder reaction conditions.