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ChemicalBook CAS DataBase List 2,3,5,6-Tetrafluorophenol
769-39-1

2,3,5,6-Tetrafluorophenol synthesis

10synthesis methods
-

Yield:769-39-1 95%

Reaction Conditions:

Stage #1: Pentafluorobenzoic acidwith sodium acetate in N,N-dimethyl-formamide; for 6 h;Reflux;
Stage #2: with sulfuric acid in N,N-dimethyl-formamide at 80; pH=< 1; for 5 h;Reflux;Solvent;Reagent/catalyst;Temperature;

Steps:

1-5 Example 4:

Put 404 grams of DMF and 202.3 grams of sodium acetate into a 1L glass reactor. Add 106.0 g of pentafluorobenzoic acid at a temperature of 50-55 °C. The reaction was heated and refluxed for 6 hours. HPLC detected that the raw material content of the reaction solution was lower than 1.0%, and dropped below 80 °C, and 143.8 g of 98% concentrated sulfuric acid was added to the kettle to adjust the pH to less than 1. Then the temperature was raised and refluxed for 5 hours. After the reflux is completed, steam distillation is performed to separate the lower organic matter. The lower organic matter was rectified to obtain 79.0 g of 2,3,5,6-tetrafluorophenol, which turned into white crystals after cooling, with a yield of 95% and a purity of 99.8%.

References:

CN113214050,2021,A Location in patent:Paragraph 0023-0032

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