Highly efficient and recyclable copper based ionic liquid catalysts for amide synthesis

Abstract

A series of Cu based ionic liquids was synthesized by the reaction of 1-butyl-3-methylimidazolium salts and copper(ii) salts. These ionic liquids were investigated as catalysts in the synthesis of amides (primary, secondary and tertiary amides). For easy separation and recycling, the Cu based ionic liquids were decorated on nanocrystalline silicalite. The materials were characterized using powder X-ray diffraction, nitrogen adsorption, scanning and transmission electron microscopy, thermogravimetric analysis, and nuclear magnetic resonance, Fourier transform infrared and UV-visible spectroscopy. The Cu based ionic liquids decorated on nanocrystalline silicalite were found to be efficient and recyclable catalysts for the amide synthesis. The catalysts were found to be stable and show negligible loss of the activity even after five cycles.