PEG-400 mediated and microwave assisted one pot three-component coupling reactions: Expedient and rapid synthesis of Hantzsch 1,4-dihydropyridines devoid of use of catalyst

Current study deals with three-component coupling reaction of aldehyde, 1,3-diketone or i¢-ketoester and ammonia in poly(ethylene glycol)-400, the US-FDA approved novel reaction media using microwave irradiation (MWI).Aseries of 1,4-DHPswere preparedwithin 1-5min using PEG-400 as a solvent without using any catalyst, gives 85-95%yields. No marginal changes in the yields were observed at high microwave power and at high temperature.Moreover, PEG-400 can be recovered and reused effectively up to five runs without significant loss of activity.