| 摘要 |
PURPOSE:To prepare the titled compound useful as a raw material for photosensitive agent, etc. in high yield without passing through an intermediate, by reacting as pentafluorobenzoic acid with zinc in an alkaline aqueous solution within a specific temperature range. CONSTITUTION:Pentafluorobenzoic acid is reacted with zinc in an alkaline aqueous solution containing lithium hydroxide, sodium hydroxide, potassium carbonate or ethylenediamine, within about 20-100 deg.C, preferably 40-70 deg.C temperature range to give the aimed 2,3,5,6-tetrafluorobenzoic acid. The amount of the alkali to be used is preferably 3-5mol based on 1mol pentafluorobenzoic acid, and the amount of the zinc to be used is preferably 1.0-2.5mol based on 1mol pentafluorobenzoic acid.
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