Facile One-Pot Synthesis of Amidoalkyl Naphthols and Benzopyrans Using Magnetic Nanoparticle-Supported Acidic Ionic Liquid as a Highly Efficient and Reusable Catalyst

An efficient and eco-friendly procedure for the synthesis of 1-amidoalkyl-2-naphthol and tetrahydrobenzo[b]pyran derivatives has been developed through a one-pot three-component condensation of aldehydes with 2-naphthol and amides, or with malononitrile and dimedone in the presence of magnetic nanoparticle supported acidic ionic liquid (AIL@MNP) as a novel heterogeneous catalyst under solvent-free conditions. This new procedure offers several advantages such as short reaction time, excellent yields, operational simplicity and without any tedious work-up for catalyst recovery or product purification. Moreover, the catalyst could be simply separated by an external magnet and reused six times without significant loss of catalytic activity.