Nucleophilic Reaction of Electron-deficient Pyridone Derivatives. II. Ring Transformation of 1-Substituted 3,5-Dinitro-4-pyridones with Sodio β-Keto Esters

Article abstract of DOI:10.1246/bcsj.53.2891

The reaction of 1-substituted 3,5-dinitro-4-pyridones <1-substituents: methyl (1a), 2-pyridyl (1b), 6-methyl-2-pyridyl (1c), and 4-pyridyl (1d)> with diethyl sodio-3-oxopentanedioate give 1-substituted 3,5-bis(ethoxycarbonyl)-4-pyridones and sodio-1,3-dinitro-2-propane.On the other hand, the reactions of the 4-pyridones (1b, 1c, and 1d) with ethyl sodioacetoacetate give ethyl 4-hydroxy-3,5-dinitrobenzoate together with aminopyridine homologues, and that of 1a gives furo<3,2-b>pyridine derivative.On the basis of the concept of soft and hard acids and bases, a stepwisenucleophilic attack of the anion of β-keto esters at the electrophilic center of the 2 and 6-positions or 2 and 3-positions of the 4-pyridones is interpret the variations of the reaction courses.