3,5-二叔丁基-4-羟基苯丙酸甲酯氨解反应机理和反应动力学

分析了 3 ,5 二叔丁基 4 羟基苯丙酸甲酯 简称 3 ,5 甲酯 (E) ]与己二胺 (DA)在二甲苯溶液中氨解反应可能存在的两种机理。以二正辛基氧化锡 (有机锡 ) (SnO)为催化剂 ,在 13 0～ 13 9℃、催化剂浓度 (1.3 86～ 5 .5 45 )× 10 3 kmol m3 、己二胺过量的情况下 ,对反应过程中体系浓度变化数据进行拟合分析 ,发现氨解过程对 3 ,5 甲酯为二级反应 ,并说明目的化合物的生成占绝对优势 ;反应过程活化能为 110 .5kJ mol,反应速度与催化剂浓度成正比 ,反应动力学表达式为dE] dt =-2 .5 68× 10 1 6exp(-1.10 5 × 10 5 RT) SnO] DA] E] 2 。

STUDY ON AMINOYSIS MECHANISM AND KINETICS OF METHYL 3,5-di-tert-BUTYL-4-HYDROXYPHENYLPROPIONATE

N,N′ Hexamethylene bis(3,5 di tert butyl 4 hydroxy phenylpropionamide) was synthesized through aminolysis of methyl 3,5 di tert butyl 4 hydroxyphenylpropionate with 1,6 hexanedimine in xylene. Two possible mechanisms of aminolysis catalyzed by organo tin oxides have been proposed. Experiments were carried out at temperature 130139 ℃, and concentration of catalyst ( 0.174 4 0.693 2)×10 3 kmol/m 3 , with the amine in excess over the ester. After detailed analysis of the data from experiments, it is clear that the aminolysis is a second order reaction for ester, and the output of objective product is dominant even in large excess of amine. Moreover, the results show that the reaction rate increases proportionately with the concentration of catalyst, and the apparent activation energy is 110.5 kJ/mol. The kinetic equation of aminolysis should be:  d \/d t=-2.568×10 16 exp(-1.105×10 5 / RT)\\\ 2.