霍夫曼降解反应制备3,5-二甲基苯胺及反应动力学研究

Preparation of 3,5-dimethylaniline by Hofmann Degradation Reaction and Its Kinetics Study

文章以均三甲苯为原料，经过氧化、胺化和降解反应得到3，5-二甲基苯胺，重点研究了由3，5-二甲基苯甲酰胺霍夫曼降解制备3，5-二甲基苯胺的反应及由N-溴代-3，5-二甲基苯甲酰胺制备3，5-二甲基苯胺反应的动力学。结果表明，在降解反应中，当物料比n（3，5-二甲基苯甲酰胺）：n（NaOH）：n（Br2）=1：12．12：4．24，重排反应温度为0℃，水解温度为90—100℃，水解时间为1h，3，5-二甲基苯胺的收率较高，为45％；动力学反应活化能（Ea）为1．04×10^5J／mol。

With mesitylene as raw material, 3, 5-Dimethylaniline was prepared through reactions of oxidization, amination and Hofmann degradation. More attention was attached to the synthesis of 3, 5-dimethylaniline through Hofmann degradation from 3, 5-dimethylbenzamide and the kinetics of the reaction which 3, 5-dimethylaniline is prepared by N-bromo-3, 5-dimethylbenzamide. The results show the optimum conditions for Hofmann degradation are as follows： the ratio of 3, 5-dimethylbenzamide to sodium hydroxide and bromine is 1：12.12：4. 24, rearrangement reaction temperature is 0 ℃, hydrolysis reaction temperature is from 90 ℃ to 100 ℃ and reaction time is lh. The yield of 3, 5-dimethylaniline is 45%, and the activation energy of the kinetics is 1.04 × 10^5 J/molo