Synthesis of 2-Amino-4-aryl-3-cyano-6-methyl-5-ethoxycarbonyl-4H-pyrans

Abstract

A one-step electrochemical synthesis of the title compounds has been devised.The starting materials are aromatic and heteroaromatic aldehydes, malononitrile and ethyl acetoacetate.The overall reaction is catalyzed by electrogenerated base (EGB) formed at a platinum cathode in acetonitrile.Substituted 2-amino-4H-pyrans are significant in a number of practical applications.Some have been shown to exhibit biological a c t i ~i t ~' ~~ and they also serve as convenient starting materials for the synthesis of esoteric condensed h e t e r ~c ~c l e s .~' ~ Synthesis of substituted 2-amino-4H-pyrans is usually a two-step process that is carried out in the presence of a base as catalyst (piperidine, morpholine or metal alkoxides) in