Knoevenagel reaction: Alum-mediated efficient green condensation of active methylene compounds with arylaldehydes

Abstract

A solvent-free stirred mixture of active methylene compounds, arylaldehyde and 10 mol% alum at 80°C afforded Knoevenagel products in excellent yields. The use of a green catalyst, the solvent-free conditions, and shorter reaction times are the main features of this efficient protocol. © 2009 Taylor & Francis.