Cornforth reagent → 1-(5-Bromo-2-fluorophenyl)ethanone

HRID 1880366Notes

Reaction equation

HRID 1880366 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:11])=[C:6]([CH:8]([OH:10])[CH3:9])[CH:7]=1.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>C(Cl)Cl>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:11])=[C:6]([C:8](=[O:10])[CH3:9])[CH:7]=1

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 441820551-(5-Bromo-2-fluorophenyl)ethanol

Product 1

HCID 226074761-(5-Bromo-2-fluorophenyl)ethanoneYield 63.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 1-(5-bromo-2-fluoro-phenyl)-ethanol (37 g, 168 mmol) in CH2Cl2 (400 mL) and pyridinium dichromate (127 g, 337 mmol) were added molecular sieves (10 g). The mixture was stirred at room temperature for 20 hours. The mixture was filtered through diatomaceous earth, washed with CH2Cl2 (3×100 mL) and concentrated. The crude product was purified by column chromatography (60-120 mesh silica gel) using 10% ethyl acetate in pet-ether to afford of 1-(5-bromo-2-fluoro-phenyl)-ethanone (23 g, 63%) as pale brown oil. 1H NMR (CDCl3): δ 7.9-8.1 (d, 1H), 7.5-7.7 (m, 1H), 6.95-7.1 (t, 1H), 2.6-2.7 (d, 3H).

Workup

  1. filtrationThe mixture was filtered through diatomaceous earth
  2. washwashed with CH2Cl2 (3×100 mL)
  3. concentrationconcentrated
  4. customThe crude product was purified by column chromatography (60-120 mesh silica gel)

Sources & evidence

ORD record
ord-a6410366601d41b19b13a1410a52250f
Source dataset
uspto-grants-2012_11
Patent number
US08318762B2

Reaction notes

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