Melamine as a Green and Reusable Catalyst for Knoevenagel Condensation at Room Temperature Under Solvent-Free Conditions

Abstract

A rapid, efficient, and ecofriendly protocol has been developed for the Knoevenagel condensation of active methylene compounds such as malononitrile or ethyl cyanoacetate with aldehydes in the presence of melamine with good to excellent yields at room temperature without solvent.

GRAPHICAL ABSTRACT

Keywords:

• Active methylene compounds
• aldehydes
• Knoevenagel condensation
• melamine

Notes

^a The reaction was carried out using melamine (0.4 mmol), aldehyde (5 mmol), and active methylene compound (5 mmol). All the products are known compounds and were identified by comparison of their melting points and spectral data with those reported.

^b Isolated yield.

^c The second run.

^d The third run.

^e The fourth run.

^f The fifth run.