Sulphamic acid-functionalized magnetic Fe3O4 nanoparticles as recyclable catalyst for synthesis of imidazoles under microwave irradiation

Abstract

Trisubstituted imidazoles have been synthesized in high yield in the presence of sulphamic acid-functionalized magnetic Fe3O4 nanoparticles (SA–MNPs) as a novel solid acid catalyst under solvent-free classical heating conditions or using microwave irradiation. The heterogeneous catalyst could be recovered easily and reused many times without significant loss of catalytic activity. An efficient procedure for the synthesis of imidazoles has been developed by condensation reaction of 1, 2-diketones, aromatic aldehydes, and ammonium acetate using sulphamic acid-functionalized Fe3O4 nanoparticles under microwave irradiation. This method offers several advantages including high yield, short reaction time, simple work-up procedure and recyclability of the magnetic catalyst.