Abstract

The Knoevenagel reaction is one of the most useful methods for the synthesis of α,β- unsaturated nitriles. We disclose an efficient protocol for the Knoevenagel reaction of aldehydes with malononitrile catalyzed by 1-alkyl-1,2,4-triazolium salts to afford the corresponding products in excellent yields. The important feature of this reaction is the catalyst; 1-alkyl-1,2,4-triazolium salts are recycled and reused. Furthermore, the reaction conditions are environment friendly and do not produce any hazardous waste.

Keywords: Aldehyde, benzylidenemalononitrile, Brønsted acid, ionic liquids, Knoevenagel reaction, reusable catalyst, triazolium salts.

Graphical Abstract