The stabilities of Meisenheimer complexes. Part 42. Kinetic studies of the reactions of methyl 3,5-dinitrobenzoate and of methyl 4-chloro-3,5-dinitrobenzoate with hydroxide ions in dimethyl sulphoxide–water mixtures. Competitive nucleophilic attack at aryl and carbonyl carbon atoms
作者:Michael R. Crampton、Colin Greenhalgh
DOI:10.1039/p29860000873
日期:——
Kinetic and equilibrium data, obtained by stopped-flow spectrophotometry, are reported for the reactions of methyl 3,5-dinitrobenzoate (1) and methyl 4-chloro-3,5-dinitrobenzoate (5) with hydroxide ions in dimethyl sulphoxide–water mixtures. There is evidence for competition between attack at carbonyl and aryl carbon atoms, the latter becoming relatively favoured as the proportion of dimethyl sulphoxide
通过停止流动的分光光度法获得的动力学和平衡数据报告了3,5-二硝基苯甲酸甲酯(1)和4-氯-3,5-二硝基苯甲酸甲酯(5)与二甲亚砜-水混合物中的氢氧根离子反应。有证据表明在羰基和芳基碳原子的进攻之间存在竞争,随着溶剂中二甲基亚砜比例的增加,芳基碳原子变得相对受青睐。结果表明,由(5)形成4-羟基-3,5-二硝基苯甲酸酯的主要途径涉及氢氧化物在羰基官能团上的进攻,然后在携带氯的环碳原子上的缓慢进攻。