PEG-200: A versatile green solvent assisted catalyst-free one-pot three-component synthesis of functionalised N-amino-3-cyano-2-pyridone

PEG-200, a biodegradable, non-toxic, economical, easily available, robust and recyclable solvent mediated one-pot three-component reaction for synthesis of diverse array of functionalised N-amino-3-cyano-2-pyridone by the reaction of aldehydes, cyanoacetohydrazide and malononitrile or ethyl cyanoacetate has been demonstrated. This protocol is a cascade type reaction that includes the series of Knoevenagel condensation, Michael addition, intramolecular cyclisation, imine-enamine tautomerization and oxidative aromatization. Utilization of biodegradable greener solvent without any supplementary catalyst, shorter reaction time than previously reported protocols, easily accessible synthons, mild reaction condition and easy purification of desired products are the foremost advantages of these protocols.