3,4-Dimethoxyphenyl methyl ketone → 2-Bromo-1-(3,4-dimethoxyphenyl)ethan-1-one

HRID 2417615Notes

Reaction equation

HRID 2417615 reaction equation
[Br:1]Br.[CH3:3][O:4][C:5]1[CH:6]=[C:7]([C:13](=[O:15])[CH3:14])[CH:8]=[CH:9][C:10]=1[O:11][CH3:12]>C(Cl)(Cl)Cl>[Br:1][CH2:14][C:13]([C:7]1[CH:8]=[CH:9][C:10]([O:11][CH3:12])=[C:5]([O:4][CH3:3])[CH:6]=1)=[O:15]

Participants

4

Reactant 2

HCID 143283,4-Dimethoxyphenyl methyl ketoneHCID 24408Bromine

Product 1

HCID 2704232-Bromo-1-(3,4-dimethoxyphenyl)ethan-1-oneYield 47.6%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

A solution of bromine (30.6 g, 1.2 eg) in chloroform (150 ml) was added dropwise to a solution of 1-(3,4-dimethoxyphenyl)-1-ethanone (28.8 g) in chloroform (50 ml) over a period of 3-5 hr. The mixture was stirred for 1.5 hr. A stream of nitrogen was passed to remove the hydrobromic acid gas. The mixture was diluted with chloroform, washed with water, aqueous sodium bicarbonate and water, dried and evaporated. The crude product (48.3 g) was passed through a silica gel column (1.5 kg) using ethyl acetate-hexane (1:4) and the eluates were evaporated to give 2-bromo-1-(3,4-dimethoxyphenyl)-1-ethanone (19.7 g), mp 87°-90° C.

Workup

  1. customto remove the hydrobromic acid gas
  2. additionThe mixture was diluted with chloroform
  3. washwashed with water, aqueous sodium bicarbonate and water
  4. customdried
  5. customevaporated
  6. customthe eluates were evaporated

Sources & evidence

ORD record
ord-b570c5faf5a74477a0094d3991df6017
Source dataset
uspto-grants-1984_09
Patent number
US04469695

Reaction notes

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