A green approach to the production of 2-pyridone derivatives promoted by infrared irradiation

An alternative is presented for promoting a reaction with infrared irradiation to obtain different 4-aryl-3-cyano-5-ethoxycarbonyl-6-methyl-2-pyridone derivatives 9a-k. The process was carried out with a green approach from the corresponding 4H-pyrans, using mild reaction conditions and infrared irradiation as the energy source. In the first stage, the reaction produced 1,2,3,4-tetrahydropyridin-2-one derivatives 8a-k, followed by an oxidative step to afford the target molecules in good yields. The structure of products 9a-k was confirmed by FT-IR, ¹H NMR and ¹³C NMR spectroscopic techniques and X-ray diffraction. It was found that the efficiency of the reaction depends on the catalyst and the solvent, as well as on the aldehyde substituents.