A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxa...A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide hydrolyze to corresponding picolinic acids. 2-Picolinic acid is further decarboxylated to pyridine. Experiments at different temperatures show that the first-order rate constants display an Arrhenius behavior with activation energies of （110.9 ±2.3）, （70.4 ± 2.1） and （61.4 ± 1.8）kJ.mo1-1 for 2- pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide, respectively. These kinetic parameters for pyridinecarboxamide hydrolysis are more reliable and accurate than those from the consecutive hydrolysis of cyanopyridines.展开更多
基金Supported by the National Natural Science Foundation of China(21176218)Zhejiang Key Innovation Team of Green Pharmaceutical Technology(2010R50043)
文摘A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide hydrolyze to corresponding picolinic acids. 2-Picolinic acid is further decarboxylated to pyridine. Experiments at different temperatures show that the first-order rate constants display an Arrhenius behavior with activation energies of （110.9 ±2.3）, （70.4 ± 2.1） and （61.4 ± 1.8）kJ.mo1-1 for 2- pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide, respectively. These kinetic parameters for pyridinecarboxamide hydrolysis are more reliable and accurate than those from the consecutive hydrolysis of cyanopyridines.
