N-butyl Pyridinium Bromide Ionic Liquid Assisted Preparation of Cobalt Oxide: An Efficient Nanocatalyst for the Synthesis of Tetrahydrobenzo[a]xanthen-11-one Derivatives

An efficient and green protocol for the synthesis of tetrahydrobenzo[a]-xanthen-11-one derivatives by one-pot, three-component coupling reaction of aromatic aldehydes, dimedone, and 2-naphthol at 100 °C under solvent-free conditions in the presence of Co3O4 nanocatalyst is described. Cobalt oxide nanocatalyst was synthesized using a simple reflux method in an aqueous medium using a pyridinium-based ionic liquid, N-butyl pyridinium bromide. Morphology, structure, and particle size of Co3O4 nanocatalyst are characterized by FE-SEM, FT-IR, and XRD spectroscopy. The present methodology offers several advantages such as high yields, short reaction times, and simple workup.