Chitosan decorated Fe3O4 nanoparticles as a magnetic catalyst in the synthesis of phenytoin derivatives†
In the present work, Fe3O4 nanoparticles were synthesized by the chemical coprecipitation process. Subsequently, the synthesized nanoparticles were modified with chitosan by a simple method and characterized by X-ray diffractometry (XRD), Fourier transform infrared spectrophotometry (FT-IR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Then, phenytoin derivatives were catalyzed by magnetic Fe3O4–chitosan nanoparticles. Fe3O4–chitosan nanoparticles were found to be a recoverable organocatalyst for the efficient synthesis of 5,5-diphenylhydantoins and 5,5-diphenyl-2-thiohydantoins from substituted benzils and urea or thiourea derivatives. The nanocatalyst could be recovered easily under a magnetic field for reuse, and considerable loss of its catalytic activity was not observed after reuse in seven consecutive runs.