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

HRID 422093Notes

Reaction equation

HRID 422093 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 (MK): 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-e3f60e57e61948a9a3e8643e86ab83c9
Source dataset
uspto-grants-2012_01
Patent number
US08101633B2

Reaction notes

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