Silica-bonded N-propylpiperazine sodium n-propionate as an efficient recyclable catalyst for one-pot synthesis of 2-amino-4-aryl-4H,8H-6-methyl-8-oxo-pyrano[3,2-b]pyran derivatives

An efficient and convenient method for synthesis of a series of 2-amino-4-aryl-4 H ,8 H -6-methyl-8-oxo-pyrano[3,2- b ]pyran derivatives by one-pot, three-component reaction of an aromatic aldehyde, malononitrile or a cyanoacetate, and 5-hydroxy-2-methyl-4 H -pyran-4-one (allomaltol) in the presence of a catalytic amount of silica-bonded N -propylpiperazine sodium n -propionate (SBPPSP), in aqueous ethanol, is described. The method has the advantages of short reaction time, mild reaction conditions, high yields, and convenience.