反应详情

In a 100 ml flask, 1-(3,5-dibromo-4-hydroxy-phenyl)-ethanone (1.2 g, 4.082 mmol) was dissolved in a solvent of anhydrous tetrahydrofuran: anhydrous diethyl ether (1:1, 12 ml). Acetic acid (0.4 ml) and bromine (2.1 ml, 4.082 mmol) were added thereto dropwise under nitrogen atmosphere and then stirred at room temperature for 2 hours. After completion of the reaction by adding water dropwise, the mixture was adjusted to pH 8 to 9 with saturated solution of sodium hydrogen carbonate and extracted with ethyl acetate, and the combined organic layer was dried over anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure. The residue was purified by column chromatography on silica eluting with a solvent of n-hexane:ethyl acetate=2:1. The fractions containing the product were collected and evaporated to obtain 2-bromo-1-(3,5-dibromo-4-hydroxy-phenyl)-ethanone as white solid (785 mg, 51.5%).

1. customAfter completion of the reaction
2. extractionextracted with ethyl acetate
3. dry with materialthe combined organic layer was dried over anhydrous sodium sulfate (Na2SO4)
4. filtrationfiltered
5. customevaporated under reduced pressure
6. customThe residue was purified by column chromatography on silica eluting with a solvent of n-hexane
7. additionThe fractions containing the product
8. customwere collected
9. customevaporated