2-,3-和4-溴甲基吡啶的水解反应的动力学研究

The Kinetic Studies of Hydrolysis of 2-, 3- and 4- Bromomethyl Pyridines

用HPLC测定了2-、3-和4-溴甲基吡啶在60℃、离子强度μ为0.15、pH0.9～9.9的缓冲溶液中水解成相应的羟甲基吡啶的反应速度.通过数学处理,求得溴甲基吡啶的一级和二级反应速度常数以及溴甲基吡啶共轭酸的一级反应速度常数.水解反应的可能机理是S_Nl和S_N2.

The rates of hydrolysis of 2-, 3- and 4-bromomethyl pyridines to the corresponding hydroxymethyl pyridines at 60℃ and ion strength μ=0. 15 over the pH range from 0. 9 to 9. 9 in buffer solutions were measured by means of HPLC. Through the mathematical treatment, the first-order and the second-order reaction-rate constants for bromomethyl pyridines and the first-order reaction-rate constants of bromomethyl pyridines conjugated acids were obtained. The mechanisms of the hydrolysis were proposed to be unimolecular nucleophilic substitution and bimolecular nucleophilic substitution (SN2).