Boron tribromide → 1-(3-Bromo-2,4-dihydroxyphenyl)ethan-1-one

HRID 2355269Notes

Reaction equation

HRID 2355269 reaction equation
[Br:1][C:2]1[C:3]([OH:13])=[C:4]([C:10](=[O:12])[CH3:11])[CH:5]=[CH:6][C:7]=1[O:8]C.B(Br)(Br)Br.ClCCl.CCCCCC>ClCCl>[Br:1][C:2]1[C:3]([OH:13])=[C:4]([C:10](=[O:12])[CH3:11])[CH:5]=[CH:6][C:7]=1[OH:8]

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 21226440Methylenechloride HexaneHCID 212700041-(3-Bromo-2-hydroxy-4-methoxyphenyl)ethanone

Product 1

HCID 591531601-(3-Bromo-2,4-dihydroxyphenyl)ethan-1-oneYield 74%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Stir 1-(3-bromo-2-hydroxy-4-methoxy-phenyl)-ethanone (20 g, 82 mmol) in dichloromethane (500 mL) at −30° C. under a nitrogen atmosphere. Treat with boron tribromide (30 mL, 318 mmol) and stir over night at room temperature. Pour mixture into cracked ice and stir for 1 hr. Extract twice with dichloromethane, wash organic layers with water, saturated aqueous sodium chloride solution, dry with magnesium sulfate, filter, and evaporate filtrate. Chromatograph residue on silica gel eluting with 2:1 dichloromethane/hexane to provide the title compound (13.8 g, 74% yield) as an off white powder. 1H NMR (CDCl3) δ 13.5 (s, 1H), 7.65 (d, J=8.0 Hz, 1H), 6.62 (d, J=8.0 Hz, 1H), 6.20 (s, 1H), 2.60 (s, 3H).

Workup

  1. additionPour mixture into cracked ice
  2. stirringstir for 1 hr
  3. extractionExtract twice with dichloromethane
  4. washwash organic layers with water, saturated aqueous sodium chloride solution
  5. dry with materialdry with magnesium sulfate
  6. filtrationfilter
  7. customevaporate filtrate

Sources & evidence

ORD record
ord-0306c0c9a52e4fbbaaec6dd702f03d05
Source dataset
uspto-grants-2010_07
Patent number
US07754742B2

Reaction notes

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