Hybrid magnetic Irish moss/Fe3O4 as a nano-biocatalyst for synthesis of imidazopyrimidine derivatives

Abstract

Irish moss (IM), derived from the Chondrus crispus is a family of sulphated polysaccharide that are extracted from certain kinds of algae (red edible seaweeds). In this study, new magnetically separable, recoverable Fe₃O₄ nanoparticles were synthesized in the presence of natural Irish moss (IM) to afford Fe₃O₄@IM. FT-IR analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), VSM analysis, Energy-Dispersive X-ray Spectroscopy (EDX) and X-ray diffraction (XRD) were combined for the characterization of the Fe₃O₄@IM nanocomposite. Afterward, the first catalytic report of Fe₃O₄@IM with no post-modification was achieved by studying its catalytic activity in the synthesis of imidazopyrimidine derivatives via a three-component reaction of 2-aminobenzimidazole, aldehyde, and C–H acidic compounds under reflux in ethanol. ¹H nuclear overhauser effect (NOE) experiments have been used to ascertain the regioselectivity of addition and condensation reactions. Based on this study, Fe₃O₄@IM is an efficient, magnetically separable, recyclable, and green catalyst.