Imidazole functionalized magnetic Fe3O4 nanoparticles as a novel heterogeneous and efficient catalyst for synthesis of dihydropyrimidinones by Biginelli reaction

Dihydropyrimidinone derivatives were synthesized in moderate to high yields in one-pot three-component condensation reactions from the corresponding aldehydes, 1,3-dicarbonyl compounds, and urea in the presence of catalytic amounts of imidazole functionalized on magnetic nanoparticles as an efficient, non-toxic, reusable, and easily available catalyst under solvent-free conditions at 80 °C. Compared to the classical Biginelli reaction, this new method consistently has the advantage of excellent yields, short reaction times, and methodological simplicity. Furthermore, the nanomagnetic catalyst could be readily handled and removed from the reaction mixture via application of an external magnet, allowing straightforward recovery and reuse. Graphical Abstract .