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

In this work, various 3-cyano-4-aryl-4H-pyran derivatives were prepared efficiently through a one-pot,multicomponent synthesis between aromatic aldehyde, malononitrile and acetophenone derivativesor ethyl acetoacetate using Fe3O4/EDTA magnetic nanocatalyst and ethanol as solvent. The reactionswere completed at room temperature in 10 min using 5 mg of catalyst and 2 mL of solvent to prepare1 mmol of the product. The employed catalyst has consisted of magnetite nanoparticles core, whichcoated with EDTA to modify its surface and prevent the aggregation. In addition, the catalytic abilitiesof different deep eutectic solvents (DESs) such as choline chloride/tin (II) chloride, choline chloride/zinc chloride and choline chloride/urea were compared with the nanomagnetic catalyst via thissynthesis. The nanomagnetic catalyst showed higher ability in comparison with various DESs for thetitle reaction. The employed nanomagnetic catalyst has been recycled 4 times without important lossof its activity which shows its high efficiency and small leaching.