An efficient and simple procedure for the preparation of 2‐pyridinone is reported. The obtained products contained various bicyclic 2‐pyridinones and multi‐substituted 6‐amino‐2‐pyridinones. This approach employed 3‐hydroxy‐2‐aryl acrylate and nitro ketene aminal as substrates, and the corresponding 2‐pyridinones were obtained in good to excellent yields. This method may be used for the synthesis of bicyclic 2‐pyridinones, as well as multi‐substituted complex 2‐pyridinones.

We report an efficient and environment‐friendly approach for the synthesis of multisubstituted 7‐oxo‐7H‐chromeno[3,2‐c]quinolin‐5‐ium salts using ambient air as a green sole oxidant. The chromeno[3,2‐c]quinolin‐5‐ium salts were prepared through metal‐free cascade intermolecular cycloaddition/oxidation reaction of 3‐formylchromones and N‐substituted anilines using HClO4 as the reagent and promoter under concise one‐pot conditions. In the applied research, the resulting quinolinium salts could serve as synthons and could be further transformed to diverse synthetically useful 3‐(2‐hydroxy‐benzoyl)quinolin‐4‐ones in water. This protocol offers a simple cascade strategy to synthesize a wide variety of natural‐like chromeno[3,2‐c]quinolin‐5‐ium salts and quinolin‐4‐ones, and shows some academic research potential as well as industrial applications.