Abstract��
2,3,4,5-Tetrafluorobenzoic acid was synthesized from tetrachlorophthalic anhydride via imidation,fluorination,hydrolysis and decarboxylation.The influences of phase transfer catalyst on imidation and fluorination,and the influences of surfactants on hydrolysis were studied respectively.Experiment results showed that imidation reaction time decreased when phase transfer catalysis method was used,and the imidation yield was 97.3%.The fluorination yield reached 81.2% when calixarene was chosen as phase transfer catalyst.In the presence of sodium dodecyl benzene sulfonate,hydrolysis reaction time decreased obviously and hydrolysis yield reached 91%.Compared with the literature method,the overall reaction time of the improved method decreased from 56 h to 11 h,and the total yield increased from 47.3% to 64.3%.
CAI Xing-wei,FENG Ya-qing,QI Xuan,ZHANG Chun-yan.Preparation of 2,3,4,5-Tetrafluoro-Benzoic Acid[J]. Chemcial Industry and Engineering, 2006,23(4): 320-322
[1]
ROZINA D S.Process for the preparation of 2,3,4,5-tetrafluoro-benzoic acid[P].US:5 179 230,1993-01-12.