Sodium Benzoate as a Green, Efficient, and Recyclable Catalyst for Knoevenagel Condensation

Abstract

Abstract Sodium benzoate was utilized as a novel efficient and green catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as ethyl cyanoacetate and malononitrile to afford substituted olefins through the conventional stirring or under ultrasounic irradiation. Improvements were observed by carrying out the reactions under ultrasound irradiation. The reaction proceeded smoothly under mild conditions at room temperature, and the products were obtained in excellent yields within short times: The catalyst remains active and exhibits no substantial loss of activity for up to four reaction cycles.