Ionic Liquid–Mediated Knoevenagel Condensation of Meldrum's Acid and Aldehydes

Abstract

Abstract A simple, efficient, and green protocol for Knoevenagel condensation of Meldrum's acid and aldehydes in ionic liquid at room temperature without any catalyst is described. The reaction has been performed in different ionic liquids. The enhancement in the rate is observed in Brönsted acidic ionic liquid 1‐methylimidazolium trifluoroacetate [Hmim]Tfa, which furnishes quantitative yields with 4–30 min in most of the cases. Furthermore, ionic liquid is easily reused without any appreciable loss in activity. Keywords: Brönsted acidic ionic liquidKnoevenagel condensationMeldrum's acidrecyclabilityylidenes Acknowledgments The authors are thankful to the Council of Scientific and Industrial Research and the Department of Science and Technology (New Delhi) for the financial support. N. B. D. and S. V. B. are thankful to CSIR for the award of junior research fellowships.