Cornforth reagent → 1-(5-Bromo-2-chlorophenyl)ethan-1-one

HRID 858785Notes

Reaction equation

HRID 858785 reaction equation
[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[Br:22][C:23]1[CH:24]=[CH:25][C:26]([Cl:32])=[C:27]([CH:29]([OH:31])[CH3:30])[CH:28]=1>C(Cl)Cl>[Br:22][C:23]1[CH:24]=[CH:25][C:26]([Cl:32])=[C:27]([C:29](=[O:31])[CH3:30])[CH:28]=1

Participants

4

Procedure

Pyridinium dichromate (2.6 g, 6.94 mmol) was added to a solution of 1-(5-bromo-2-chloro-phenyl)-ethanol (1.09 g, 4.6 mmol) in CH2Cl2 (20 mL). The reaction was stirred for 15 hours and then more pyridinium dichromate (2.6 g, 6.94 mmol) was added. After another 24 hours celite was added and the mixture was stirred for 20 mins. The reaction mixture was filtered through a pad of celite washing with ether. The filtrate was concentrated to a brown oil. The residue was purified by flash silica gel chromatography (0% to 10% EtOAc in hexanes) to give the title compound as a clear oil (0.92 g, 85%). 1H NMR (400 MHz, CDCl3): δ 2.64 (s, 3H), 7.29 (d, J=8.6 Hz, 1 H), 7.51 (dd, J=8.6, 2.3 Hz, 1 H), 7.66 (d, J=2.3 Hz, 1 H).

Workup

  1. additionAfter another 24 hours celite was added
  2. stirringthe mixture was stirred for 20 mins
  3. filtrationThe reaction mixture was filtered through a pad of celite
  4. washwashing with ether
  5. concentrationThe filtrate was concentrated to a brown oil
  6. customThe residue was purified by flash silica gel chromatography (0% to 10% EtOAc in hexanes)

Sources & evidence

ORD record
ord-27319599dd4f4126a9a17fd23917cf76
Source dataset
uspto-grants-2006_12
Patent number
US07148226B2

Reaction notes

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