Synthesis of quinaldines and lepidines by a Doebner–Miller reaction under thermal and microwave irradiation conditions using phosphotungstic acid

A simple and efficient method has been developed for the synthesis of quinaldines and lepidines by a one-pot reaction of anilines with crotonaldehyde or methyl vinyl ketone using phosphotungstic acid, a Keggins-type heteropoly acid, under both thermal and microwave irradiation conditions.