反应详情

Boron tribromide (1M methylene chloride solution, 100 mL) was gradually added dropwise to a methylene chloride (100 mL) solution of 3-methoxy-4-fluoro benzaldehyde (4.4 g) under ice-cooling. The reaction solution was agitated at room temperature for 2 hours after the dropping ended. The reaction solution was again cooled with ice, iced water was gradually added to the reaction solution to terminate the reaction, and further 5N hydrochloride solution was added until the pH reached 1. After condensing the reaction solution under reduced pressure, water and ethyl acetate were added to the residue, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride solution, and the solvent was evaporated under reduced pressure after dried over anhydrous magnesium sulfate. The obtained residue was purified by silica gel column chromatography (elution solvent:heptane-ethyl acetate 4:1), and 3.18 g (79%) of 4-fluoro-3-hydroxybenzaldehyde was obtained. The physical properties of the compound are as follows.

1. temperaturecooling
2. additionwas gradually added to the reaction solution
3. customto terminate
4. customthe reaction, and further 5N hydrochloride solution
5. additionwas added until the pH
6. additionwere added to the residue
7. customthe organic layer was separated
8. washThe obtained organic layer was washed with a saturated sodium chloride solution
9. customthe solvent was evaporated under reduced pressure
10. dry with materialafter dried over anhydrous magnesium sulfate
11. customThe obtained residue was purified by silica gel column chromatography (elution solvent:heptane-ethyl acetate 4:1)