Copper Perchlorate Hexahydrate: An Efficient Catalyst for the Green Synthesis of Polyhydroquinolines under Ultrasonication.

Copper perchlorate hexahydrate as an efficient catalyst was used for the synthesis of polyhydroquinolines by four-component condensation reaction of aldehyde, ethyl acetoacetate, dimedone, and ammonium acetate in excellent yields and short reaction times at room temperature under ultrasound irradiation. This novel synthetic method is especially favoured because it provides a synergy between copper perchlorate hexahydrate and ultrasound irradiation which offers the advantages of high yields, short reaction times, simplicity, and easy workup compared to the conventional methods reported in the literature.