A Green Approach to the Production of 2-pyridone Derivatives Promoted by Infrared Irradiation

Abstract

<p>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 <strong>9a-k</strong>. The process was carried out with a green approach from the corresponding 4<em>H</em>-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 <strong>8a-k</strong>, followed by an oxidative step to afford the target molecules in good yields. The structure of products <strong>9a-k</strong> was confirmed by FT-IR, <sup>1</sup>H NMR and <sup>13</sup>C 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.</p>

Keggin heteropolyacid in auto-tandem catalysis: confinement effects over ordered mesoporous silica in the synthesis of 2-pyridones

“…52 a–f Our group previously reported a two-step methodology for the transformation of 2-amino-4 H -pyrans through a ring opening/ring closure sequence under acid conditions, followed by oxidation with DDQ. 53 To demonstrate the potential application of the duality of HPAs and other POMs in organic synthesis, the aim of the current contribution was to synthesize a multicatalytic hybrid system by the immobilization of the Keggin HPA (H 3 PW 12 O 40 ), herein denominated HPW, by anion metathesis on mesoporous silica material (SBA-15 and MCF) covalently grafted with ionic liquid moieties. The resulting catalysts were characterized by numerous techniques and evaluated by synthesizing 2-pyridones.…”