Methanol → 1-(2-Bromo-3-hydroxyphenyl)ethanone

Temperature

-40 °C

Under a nitrogen atmosphere, 1-(2-bromo-3-methoxy phenyl)ethanone (30.5 g, 229 mmol) which had been obtained in Reference example 3 (3b) was dissolved in methylene chloride (500 mL), and added dropwise with a 1.0 M solution of tribromo phosphine in dichloromethane (293 mL, 293 mmol) at −80° C. over 5 hours. Upon the completion of the dropwise addition, the mixture was stirred for 17 hours at −40° C. Subsequently, the reaction solution was cooled to −80° C. and added dropwise with methanol (500 mL). Upon the completion of the dropwise addition, the temperature was raised to −40° C. followed by stirring for 3 hours. The temperature of the reaction solution was raised to room temperature. The solvent was distilled off under reduced pressure until the solution turned green. After adding ethanol, the mixture was extracted with ethyl acetate/hexane (1:1, V/V). After neutralization with a saturated aqueous solution of sodium hydrogen carbonate, the solvent was distilled off under reduced pressure. The residue was purified by silica gel chromatography (hexane:ethyl acetate, 100:0-55:45, V/V) to give the title compound as a colorless oily substance (13.5 g, yield 47%).

1. additionUpon the completion of the dropwise addition
2. temperatureSubsequently, the reaction solution was cooled to −80° C.
3. additionUpon the completion of the dropwise addition
4. temperaturethe temperature was raised to −40° C.
5. stirringby stirring for 3 hours
6. temperatureThe temperature of the reaction solution was raised to room temperature
7. distillationThe solvent was distilled off under reduced pressure until the solution
8. additionAfter adding ethanol
9. extractionthe mixture was extracted with ethyl acetate/hexane (1:1, V/V)
10. distillationAfter neutralization with a saturated aqueous solution of sodium hydrogen carbonate, the solvent was distilled off under reduced pressure
11. customThe residue was purified by silica gel chromatography (hexane:ethyl acetate, 100:0-55:45, V/V)

ORD record

ord-7617058e45494fd2a7bb1858fe0424a3

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08173631B2