Kinetic study on the anelation of heterocycles.<b>1</b>. Quinoxalinone derivatives synthesized by hinsberg reaction
作者:María I. Abasolo、Carlos H. Gaozza、Beatriz M. Fernández
DOI:10.1002/jhet.5570240651
日期:1987.11
benzene-substituted 3-methylquinoxalin-2(1H)-ones. The course of the reactions between o-phenylenediamine (o-PDA) and substituted o-PDA with pyruvic acid (2a) or ethyl pyruvate (2b) were followed by uv spectrophotometry at different pH values. The formation of 3-methylquinoxalin-2(1H)-one (6a) was improved using sulphuric acid-water mixtures, in which the reaction proceeded by a different mechanism. 3
进行了Hinsberg缩合反应的动力学研究,以提高收率并实现苯取代的3-甲基喹喔啉-2(1 H)-one的区域选择性。反应之间的过程Ô苯二胺(ø -PDA)和取代的ö -PDA与丙酮酸(图2a)或丙酮酸乙酯(图2b)中,随后在不同的紫外分光光度法p ħ值。使用硫酸-水混合物改善了3-甲基喹喔啉-2(1 H)-one(6a)的形成,其中反应通过不同的机理进行。3-甲基-7-甲氧基喹喔啉-2(1 H)-一(与反应介质的p H无关地区域选择性地合成图7b)。2-氨基-4-甲胺(1c)与2a或2b反应生成6和7-喹喔啉酮异构体6c和7c的混合物,而2-氨基-4-硝基苯胺(1d)和2,4-二氨基苯胺(1d)具有2a或2b的1e)没有提供杂环。在每种情况下,2a的反应比2b的反应快100-1000倍。提出了试图解释实验结果的机制。