A cheap and recyclable silica (NPs) supported Fe (III) was prepared as heterogeneous catalyst for the synthesis of various substituted 1,4-dihydropyridines via condensation of aldehydes with ethyl acetoacetate and ammonium acetate in ethanol. The products were separated from the catalyst simply by filtration and the catalyst could be recycled and reused for several times without noticeable decrease in the catalytic activity.
