摘要
采用湿Pd(OH)2/C催化剂在排除扩散影响的条件下,研究了常压下N-乙酰保护胞壁酸(PNAM)在w(乙酸)=80%的溶剂中氢解脱苄合成N-乙酰胞壁酸(NAM)的反应动力学。通过空白实验消除湿Pd(OH)2/C及溶剂对吸氢量的影响,以吸氢量来表征反应程度。通过积分反应速率方程,对不同温度下该反应的实验数据进行了动力学计算。实验结果表明,在实验条件下,PNAM加氢脱苄反应合成NAM反应表现为一级,反应表观活化能Ea为76.496 kJ.mol-1,指前因子A为4.868×1010min-1。用IR、1HNMR、13CNMR、LC-MS和元素分析对产物进行了表征,证实了该化合物即是目标产物NAM。
The reaction kinetics of synthesis of N-acetylmuramic acid （NAM） by hydrogenolysis debenzylation of protected N-acetylmuramic acid （PNAM） was studied over wet Pd（OH） 2/C catalyst in the solution of 80% acetic acid. The experiment was carried out in an atmosphere of hydrogen. The effects of both internal and external diffusions were eliminated by stirring adequately. The effects of catalyst and solvent were eliminated by the experiments without adding substrate. The change of absorption amount of hydrogen with reaction time was measured to monitor the course of reaction. Kinetic calculations of the experimental data at various temperatures were done according to the integrated reaction rate equation. Experimental results indicate that the reaction is first-order with respect to PNAM under the experimental conditions. The apparent activation energy（Ea ） of the reaction is 76. 496 kJ·mol^-1 and pre-exponential factor （A） is 4, 868×10^10 min^-1. Structure of NAM was verified by IR, ^1HNMR, ^13CNMR, LC -MS and elementary analysis.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2008年第4期372-375,共4页
Fine Chemicals
