Boron tribromide → 5-Bromo-2-chlorophenol

To 50 mL of a 1M solution of boron tribromide in CH2Cl2 at 0° C. was added 5.71 g (25.8 mmol) of 5-Bromo-2-chloroanisole. After 2 hours, the reaction was allowed to warm to room temperature. After 5 hours, the solution was cooled to 0° C., and quenched with methanol. The resulting solution was partitioned between water and ethyl acetate, and the phases were separated. The aqueous phase was back-extracted once with ethyl acetate. The combined ethyl acetate phases were diluted with one volume of ether, and were extracted twice with 1M NaOH. The combined basic aqueous phases were acidified with 12M HCl, and were extracted once with ethyl acetate. The final ethyl acetate phase was washed once with brine, dried over MgSO4, filtered, and concentrated to give the phenol as a tan solid. 1H NMR (DMSO-d6, 400 MHz) 10.66 (s, 1H), 7.27 (d, 1H), 7.08 (s, 1H), 6.95 (d, 1H) ppm.

1. waitAfter 5 hours
2. temperaturethe solution was cooled to 0° C.
3. customquenched with methanol
4. customThe resulting solution was partitioned between water and ethyl acetate
5. customthe phases were separated
6. extractionThe aqueous phase was back-extracted once with ethyl acetate
7. additionThe combined ethyl acetate phases were diluted with one volume of ether
8. extractionwere extracted twice with 1M NaOH
9. extractionwere extracted once with ethyl acetate
10. washThe final ethyl acetate phase was washed once with brine
11. dry with materialdried over MgSO4
12. filtrationfiltered
13. concentrationconcentrated

ORD record

ord-230ddab561e644d585818e6b429a3379

Source dataset

uspto-grants-2007_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07157464B2