Binding of Polyethylene Glycol Imidazolium Hydrogen Sulfate to Magnetic Nanoparticles and Its Application as a Novel Recyclable Solid Acid Catalyst in the Friedländer Synthesis of Quinolines under Solvent-Free Conditions

Abstract

For the first time, a new acidic imidazolium-based ionic liquid supported on magnetic nanoparticles (MNP@PEG-ImHSO4) was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDAX), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) techniques. Afterwards, its catalytic activity was investigated in the Friedländer synthesis of quinolines through a condensation reaction between 2-aminoaryl ketones and α-methylene ketones under solvent-free conditions. The catalyst could readily be separated from the reaction mixture using an external magnet and could be reused in subsequent reactions with no significant loss of activity.