Alumina-Supported Cobalt Nanoparticles Efficiently Catalyzed the Synthesis of Chromene Derivatives under Solvent-Free Condition

In this research study, an efficient approach is reported for the solvent-free synthesis of various chromene derivatives catalyzed by alumina-supported cobalt nanoparticles in high yields. Alumina-supported cobalt nanoparticles (Co/Al2O3 nanocatalyst), efficiently catalyzed the reaction between the resorcinol or 2-hydroxy naphthalene with benzaldehyde and malononitrile into chromene derivatives in high efficiency. This procedure allowed us to obtain corresponding products in short reaction times, simple work-up, and high yields. Experimental procedure with Co/Al2O3 nanocatalyst is very simple and the catalyst is easily removed by filtration. The catalyst was also found to be recyclable and can catalyze synthesis of the chromenes up to 5 times well.