Boron tribromide → 3-Bromo-5-methoxyphenol

HRID 500615Notes

Reaction equation

HRID 500615 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[C:4]([O:10]C)[CH:3]=1.B(Br)(Br)Br>ClCCl>[Br:1][C:2]1[CH:3]=[C:4]([OH:10])[CH:5]=[C:6]([O:8][CH3:9])[CH:7]=1

Participants

4

Conditions

Temperature
-78 °C

Procedure

1-bromo-3,5-dimethyoxybenzene (3.0 g, 13.8 mmol) was dissolved in dichloromethane (45 mL) and the solution was cooled to −78° C. Boron tribromide (1M in dichloromethane, 41 mL, 41 mmol) was added and the solution was warmed gradually to room temperature over 18 hours. After cooling to −78° C., the reaction was quenched with water (100 mL). The organics were separated and washed with sodium thiosulphate solution then water, then dried over magnesium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel, eluting with pentane:ethyl acetate 100:0 to 80:20, to afford the title compound in 16% yield (470 mg).

Workup

  1. temperaturethe solution was warmed gradually to room temperature over 18 hours
  2. temperatureAfter cooling to −78° C.
  3. customthe reaction was quenched with water (100 mL)
  4. customThe organics were separated
  5. washwashed with sodium thiosulphate solution
  6. dry with materialwater, then dried over magnesium sulfate
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified by column chromatography on silica gel
  9. washeluting with pentane:ethyl acetate 100:0 to 80:20

Sources & evidence

ORD record
ord-5e35e8d0a80f4483a1bf328707706edf
Source dataset
uspto-grants-2010_08
Patent number
US07772223B2

Reaction notes

Loading…