High Catalytic Ability of Fe3O4/EDTA Magnetic Nanocatalyst in Comparison with Various Deep Eutectic Solvents for One-Pot Synthesis of 4H-Pyrans

Abstract

In this work, various 3-cyano-4-aryl-4H-pyran derivatives were prepared efficiently through a one-pot,<br />multicomponent synthesis between aromatic aldehyde, malononitrile and acetophenone derivatives<br />or ethyl acetoacetate using Fe3O4/EDTA magnetic nanocatalyst and ethanol as solvent. The reactions<br />were completed at room temperature in 10 min using 5 mg of catalyst and 2 mL of solvent to prepare<br />1 mmol of the product. The employed catalyst has consisted of magnetite nanoparticles core, which<br />coated with EDTA to modify its surface and prevent the aggregation. In addition, the catalytic abilities<br />of different deep eutectic solvents (DESs) such as choline chloride/tin (II) chloride, choline chloride/<br />zinc chloride and choline chloride/urea were compared with the nanomagnetic catalyst via this<br />synthesis. The nanomagnetic catalyst showed higher ability in comparison with various DESs for the<br />title reaction. The employed nanomagnetic catalyst has been recycled 4 times without important loss<br />of its activity which shows its high efficiency and small leaching.