Nucleophilic Reaction of Electron-deficient Pyridone Derivatives. II. Ring Transformation of 1-Substituted 3,5-Dinitro-4-pyridones with Sodio β-Keto Esters
作者:Eizo Matsumura、Masahiro Ariga、Yasuo Tohda
DOI:10.1246/bcsj.53.2891
日期:1980.10
The reactions 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 la gives furo [3,2-b] pyridine derivative. On the basis of the concept of soft and hard acids and bases, a stepwise nucleophilic 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 proposed to interpret the variations of the reaction courses.
1-取代的3,5-二硝基-4-吡啶酮 [1-取代基:甲基 (1a)、2-吡啶基 (1b)、6-甲基-2-吡啶基 (1c) 和4-吡啶基 (1d)] 与二乙基钠-3-氧代戊二酸酯的反应生成1-取代的3,5-双(乙氧基羧基)-4-吡啶酮和钠-1,3-二硝基-2-丙烷。另一方面,4-吡啶酮 (1b、1c 和 1d) 与乙基钠乙酰乙酸酯的反应生成乙基4-羟基-3,5-二硝基苯甲酸酯及其氨基吡啶衍生物,而1a的反应则生成呋喹[3,2-b]吡啶衍生物。基于软酸和硬酸及碱的概念,建议提出β-酮酯阴离子对4-吡啶酮的2和6位或2和3位的亲核攻击为逐步发生,以解释反应路线的变化。