V2O5/ZrO2 as an efficient reusable catalyst for the facile, green, one-pot synthesis of novel functionalized 1,4-dihydropyridine derivatives

A practical method is designated for the one-pot, multicomponent synthesis of 1,4-dihydropyridine derivatives by cyclo-condensation of aromatic aldehydes, 5,5-dimethyl-1,3-cyclohexanedione, acetoacetanilide and ammonium acetate. Using ethanol as solvent and V2O5/ZrO2 as heterogeneous catalyst, ten novel 1,4-dihydropyridines were synthesized at room temperature (Reaction time< 20 min). XRD, TEM, SEM and BET analysis were used to characterize the catalyst materials. Simple work-up, green solvent, short reaction times, moderate reaction conditions and excellent yields (90-96%) are the attractive features of this novel approach. With no need of chromatographic separation, the reaction product is easily separable in pure form.