Microwave accelerated the solvent-free synthesis of 4-aryl-3,4-dihydrocoumarin via the tandem reaction of cinnamic acids with phenols catalyzed by Amberlyst 15 resin

Abstract

Amberlyst 15 resin supported the tandem reaction of cinnamic acids with phenols under solvent-free reaction condition has been introduced to afford 4-aryl-3,4-dihydrocoumarin (neoflavanone) derivatives. The efficiency of solid acidic sulfonic resin (A-15) has been illustrated in two reaction activation methods such as microwave irradiation and conventional heating. The important roles of Amberlyst 15 have been emphasized strongly through the high yields of 4-aryl-3,4-dihydrocoumarin in the shorter time under the assistance of microwave irradiation than of conventional heating, and its high recovery and reusability for six catalyst runs. The original catalyst as well as the recycled catalyst were characterized by XRD and FE-SEM to study the correlation of the surface of reused catalyst and its recyclability.