Bromine → 2-Bromo-1-(4-bromo-3,5-dimethoxyphenyl)ethanone

HRID 2359149Notes

Reaction equation

HRID 2359149 reaction equation
[Br:1][C:2]1[C:7]([O:8][CH3:9])=[CH:6][C:5]([C:10](=[O:12])[CH3:11])=[CH:4][C:3]=1[O:13][CH3:14].[Br:15]Br.C([O-])(O)=O.[Na+]>C(Cl)Cl>[Br:15][CH2:11][C:10]([C:5]1[CH:6]=[C:7]([O:8][CH3:9])[C:2]([Br:1])=[C:3]([O:13][CH3:14])[CH:4]=1)=[O:12]

Participants

5

Reactant 3

HCID 24408BromineHCID 516892Sodium BicarbonateHCID 584320901-(4-Bromo-3,5-dimethoxyphenyl)ethan-1-one

Product 1

HCID 584320022-Bromo-1-(4-bromo-3,5-dimethoxyphenyl)ethanoneYield 63%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

To a solution of 1-(4-bromo-3,5-dimethoxyphenyl)ethanone (0.895 g, 3.45 mmol) in anhydrous CH2Cl2 (5 mL) under a drying tube was added a freshly made solution of Br2 in CH2Cl2 (1.95 M, 1.9 mL, 3.7 mmol) dropwise. The reaction was stirred at room temperature for 30 min then neutralized with a solution of saturated aqueous NaHCO3. The mixture was diluted with CH2Cl2 and the layers were separated. The organics were washed with saturated aqueous NaHCO3 and brine then dried over MgSO4/Na2SO4 and concentrated in vacuo. The crude product was adsorbed onto silica gel (2.9 g) as a CH2Cl2 solution. Purification by chromatography (0-20% EtOAc-hexanes) gave 2-bromo-1-(4-bromo-3,5-dimethoxyphenyl)ethanone as a white solid (0.737 g, 63% yield). Large-scale synthesis of 2-bromo-1-(4-bromo-3,5-dimethoxyphenyl)ethanone was performed without chromatographic purification of the bromide.

Workup

  1. customthe layers were separated
  2. washThe organics were washed with saturated aqueous NaHCO3 and brine
  3. dry with materialthen dried over MgSO4/Na2SO4
  4. concentrationconcentrated in vacuo
  5. customPurification by chromatography (0-20% EtOAc-hexanes)

Sources & evidence

ORD record
ord-ce1f310928b34fea834957bb195f60c6
Source dataset
uspto-grants-2014_04
Patent number
US08685975B2

Reaction notes

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