Nucleophilic Reaction upon Electron-Deficient Pyridone Derivatives. XIII. Regioselective Synthesis of 2-Substituted 3-Nitropyridines by One-Pot Reaction of Either 4- or 6-Substituted 1-Methyl-3,5-dinitro-2-pyridones with Ketones and Ammonia
作者:Yasuo Tohda、Tohru Kawahara、Miyuki Eiraku、Keita Tani、Nagatoshi Nisiwaki、Masahiro Ariga
DOI:10.1246/bcsj.67.2176
日期:1994.8
A one-pot synthesis of 2-substituted 3-nitropyridines was developed by a ring transformation of 6- or 4-substituted 1-methyl-3,5-dinitro-2-pyridones (2 or 3) with ammonia and enamines derived from ketones. Some intermediates having a 2,6-diazabicyclo[3.3.1]nonane skeleton were isolated from reactions of 3. The ring transformation proceeds via an addition-addition-elimination-elimination mechanism.
2-取代 3-硝基吡啶的一锅合成是通过 6-或 4-取代的 1-甲基-3,5-二硝基-2-吡啶酮(2 或 3)与氨和酮衍生的烯胺的环转化而开发的. 一些具有2,6-二氮杂双环[3.3.1]壬烷骨架的中间体从3的反应中分离出来。环转化通过加成-加成-消除-消除机制进行。形成了很少的竞争性异构副产物,即 4-取代的 3-硝基吡啶和 4-硝基苯胺。2 种底物均表现出良好的反应性,但具有吸电子取代基的 3 种底物反应性和选择性较差。1,4,6-三甲基-3,5-二硝基-2-吡啶酮没有得到任何产物。