反应详情

A process for preparing 3,5,6-trifluoro-4-hydroxyphthalic acid used here as the starting material is described in Osadchii, S. A., Bakahash, V. A.; Zh. Org. Khim., Vol. 6 (8), p. 1636 (1970) (Chemical Abstract, 73, 109544p). According to this litrature, when tetrafluorophthalic anhydride and pentafluorophenylacetic acid are reacted in triethylamine-acetic anhydride, a triethylamine salt of 5-hydroxy-4,6,7-trifluoro-3-(pentafluorobenzylidene)phthalide is obtained. And, by treatment of the by-products of this reaction, 3,5,6-trifluoro-4-hydroxyphthalic acid is obtained.