4-Bromo-2,3-difluorophenol synthesis

Yield: 73%

Reaction Conditions:

with acetic acid;potassium bromide in water;acetic acid at 35;regioselective reaction;

Steps:

4.2. General Procedure for the Bromination
General procedure: 0.11 g (1.0 mmol) of 4-methylphenol, 5 mL of acetic acid, 0.5 mL of water, and 0.12 g (1.0 mmol)potassium bromide were placed in round-bottomed flask. Then, 0.19 g (0.2 mmol)ZnAl-BrO3--LDHs was added in the flask under stirring at 35 °C. After the addition, stirring wascontinued to the end of reaction (monitored by thin layer chromatography). The residualZnAl-BrO3--LDHs were removed by centrifugation. The product was extracted with 3 × 10 mLdichloromethane. The combined extract was washed with sodium sulfite solution, brine, and dried(Na2SO4). Evaporation of the solvent left the crude product. The crude product was purified bycolumn chromatography over silica gel (ethyl acetate-petroleum ether) to obtain pure product.

References:

Wang, Ligeng;Feng, Chun;Zhang, Yan;Hu, Jun [Molecules,2020,vol. 25,# 4,art. no. 914] Location in patent:supporting information