p-METHYLACETOPHENONE → 2-Bromo-4'-methylacetophenone

HRID 500749Notes

Reaction equation

HRID 500749 reaction equation
[C:1]1([CH3:10])[CH:6]=[CH:5][C:4]([C:7](=[O:9])[CH3:8])=[CH:3][CH:2]=1.[Br-:11].[Br-].[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC>ClCCl.CO>[Br:11][CH2:8][C:7]([C:4]1[CH:5]=[CH:6][C:1]([CH3:10])=[CH:2][CH:3]=1)=[O:9]

Participants

4

Reactant 2

HCID 8500p-METHYLACETOPHENONEHCID 23500184Tetra-n-butylammonium tribromide

Product 1

HCID 692722-Bromo-4'-methylacetophenoneYield 84%

Reagents, catalysts & solvents 1

HCID 21226129Dichloromethane methanolSolvent

Procedure

To a solution of 1-p-tolyl-ethanone (0.5 g, 4.16 mmol) in dichloromethane-methanol (50 ml-20 mL) was added tetrabutylammonium tribromide (2.2 g, 4.58 mmol) at room temperature. The mixture was stirred until the orange color faded. The solvent was then distilled under reduced pressure and the resulting precipitate was extracted with ethyl acetate. The organic layer was dried over sodium sulfate and evaporated in vacuo to give a residue which was purified by flash column chromatography to yield the desired product 2-bromo-1-p-tolyl-1-ethanone (0.74 g, 84%). 1H NMR (300 MHz, DMSO-d6) δ 2.39 (s, 3H), 4.89 (s, 2H), 7.37 (d, 2H), 7.89 (d, 2H); ESI-MS (MH+): 213 and 215.

Workup

  1. distillationThe solvent was then distilled under reduced pressure
  2. extractionthe resulting precipitate was extracted with ethyl acetate
  3. dry with materialThe organic layer was dried over sodium sulfate
  4. customevaporated in vacuo
  5. customto give a residue which
  6. customwas purified by flash column chromatography

Sources & evidence

ORD record
ord-a9b151c6b0a743549ed15e2759fde192
Source dataset
uspto-grants-2010_08
Patent number
US07772248B2

Reaction notes

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