decarboxylation process. The pyrolysis kinetics of picolinic acid, which is an intermediate of ethyl picolinate elimination, showed a dramatic fast decomposition into pyridine and CO2 gas. The decarboxylation process of α-amino or α-nitrogen substituents of carboxylic acids differs from the decarbonylation elimination of several known α-substituted carboxylic acids in the gas phase. Copyright © 2002 John
在静态反应系统中,在180.8–419.4°C的温度范围和15-86 Torr的压力范围(1 Torr = 133.3 Pa)下,确定了气相消除标题化合物的动力学。反应是均相的和单分子的,并且服从一阶速率定律。观察到的速率系数由以下Arrhenius方程表示:对于
吡啶甲酸乙酯,log [ k 1(s -1)] =(11.30±0.24)-(180.9±3.0)kJ mol -1(2.303 RT)-1, 1-甲基
哌嗪酸
乙酯,log [ k 1(s -1)] =(13.36±0.31)-(209.5±3.9)kJ mol -1(2.303 RT)-1对于
吡啶甲酸,log [ k 1(s -1)] =(12.05±0.10)-(135.7±0.9)kJ mol -1(2.303 RT)-1。这项工作的数据与文献报道的数据一起,证实了先前的考虑,即
氨基酸或
羧酸的α-氮取代基会经历非常快速的脱羧过