Synthesis of pyranopyrazoles using isonicotinic acid as a dual and biological organocatalyst†
Abstract
In this study, a green, simple and efficient method for the preparation of 6-amino-4-(4-methoxyphenyl)-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles by means of a one-pot four component condensation reaction of aryl aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate is reported. The reaction utilizes isonicotinic acid as a dual and biological organocatalyst at 85 °C under solvent-free conditions.