Synthesis of ortho-Hydroxybenzophenones Catalyzed by Magnetically Retrievable Fe3O4 Nanoparticles under Ligand-Free Conditions

ortho-Benzoylation of phenols with aryl aldehydes to afford the substituted 2-hydroxybenzophenones can be catalyzed efficiently by Fe3O4 nanoparticles under ligand-free conditions. This method is useful for the preparation of xanthones in good yields. The catalyst can be magnetically removed and recycled easily over four cycles without a significant decrease in activity.