Decarboxylation of tetrafluorophthalic acid in NH3-enriched high temperature liquid water

作者：Fu, Jie; Mo, Jing; Zhang, Jing; Lu, Xiuyang^*

来源：Applied Catalysis A: General , 2016, 515: 10-15.

DOI：10.1016/j.apcata.2016.01.034

• NH3-enriched
• High temperature liquid water
• Decarboxylation
• 2,3,4,5-Tetrafluorobenzoic acid
• Kinetics

2,3,4,5-Tetrafluorobenzoic acid is an important pharmaceutical intermediate. A green technology for the decarboxylation of tetrafluorophthalic acid to 2,3,4,5-tetrafluorobenzoic acid in NH3-enriched high temperature liquid water (HTLW) was developed. Tetrafluorophthalic acid could undergo the decarboxylation with the catalysis of NH3 to 2,3,4,5-tetrafluorobenzoic acid in HTLW. A conversion of 98.1% and selectivity of 96.5% were achieved at 453.15 K for 1.5 h with an ammonia concentration of 13.4 mmol/L. The effects of ammonia concentration, initial concentration of reactant and reaction temperature were then investigated and correlated using a derivated equation. The results indicated that adequate addition of ammonia could adjust the pH of the reaction medium into 2.2-2.4, where the dominant form of the decarboxylation is the monovalent anion. Moreover, the kinetic data at different temperatures were fitted by a first-order equation, and the rate constants at each temperature and an activation energy of 190 kJ/mol were obtained.

• 出版日期2016-4-10
• 单位浙江大学