Synthesis of Aminopyran Using Green Catalyst at Room Temperature

A simple, efficient and step-economy one-pot synthesis to afford the library of Ethyl 6-amino-4-phenyl-5-cyano-2-methyl-4H-pyran-3-carboxylate derivatives from readily available substrates malononitrile, an active methylene group and substituted aromatic aldehyde using novel heterogeneous calcined Mg-Fe-CO3 hydrotalcite at room temperature. The calcined Mg-Fe hydrotalcite with the molar ratio of 3:1 derived from calcination at 500°C was found to be a suitable catalyst that gives the highest basicity and best catalytic activity. The catalysts were characterized by XRD, TGA, SEM and Hammett titration method. The reaction is rapid, clean, easy to work up, high activity of the catalyst and gives a product in high yields. The catalyst is reusable. However, the yield of product remains same even after reusing of catalyst number of times.