Chitosan: a sustainable, reusable and biodegradable organocatalyst for green synthesis of 1,4-dihydropyridine derivatives under solvent-free condition

摘要

Chitosan, a biodegradable green catalyst, was found to be an impressive system for one-pot four-component reaction of different aldehydes, dimedone, beta aEuroketoesters or acetoacetanilide, and ammonium acetate leading to 1,4-dihydropyridine derivatives via Hantzsch-type condensation under solvent-free condition. This methodology produces diverse superiorities such as operational simplicity, short reaction time, satisfied yield and recyclable catalyst. In this work, we attempted to develop several modifications for the classical Hantzsch conversion to report a novel eco-friendly method that is free from previously reported disadvantages.