Piperazine-functionalized nickel ferrite nanoparticles as efficient and reusable catalysts for the solvent-free synthesis of 2-amino-4H-chromenes

Piperazine-functionalized nickel ferrite (NiFe2O4) nanoparticles were synthesized as recoverable heterogeneous base catalysts using a routine method. The synthesized materials were characterized using various spectroscopic techniques such as infrared, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray, thermogravimetry analysis, and vibrating sample magnetometry. Catalytic efficiency was investigated in the synthesis of 2-amino-4H-chromene derivatives via a one-pot three component reaction of aldehyde and malononitrile with beta or alpha-naphthol/5-methyle resorcinol under solvent-free conditions with good to high yields. This method is operationally simple and has several advantages such as good to high yield, short reaction times, solvent-free conditions, and easy synthesis. Moreover, the catalyst was recovered easily using an external magnet and reused three times without distinctive loss in catalytic activity.