An Efficient One-Pot Four-Component Hantzsch Reaction to Prepare Hydroquinolines Catalyzed by a Poly(ethylene glycol) Bridged Dicationic Basic Ionic Liquid under Solvent-Free Conditions

A piperidine-functionalized poly (ethylene glycol) bridged dicationic ionic liquid PEG800-DPIL(Cl) was synthesized and applied to catalyze the four-component Hantzsch reaction under solvent-free conditions and afford hydroquinolines with high to excellent yields. PEG800-DPIL(Cl) could be recovered by simple workup and recycled for at least eight times without obvious activity loss.