Cornforth reagent → 1-(5-Bromo-2-fluorophenyl)-3-(tert-butyldimethylsilyloxy)-2,2-difluoropropan-1-one

HRID 221773Notes

Reaction equation

HRID 221773 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:22])=[C:6]([CH:8]([OH:21])[C:9]([F:20])([F:19])[CH2:10][O:11][Si:12]([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13])[CH:7]=1.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:22])=[C:6]([C:8](=[O:21])[C:9]([F:19])([F:20])[CH2:10][O:11][Si:12]([C:15]([CH3:18])([CH3:16])[CH3:17])([CH3:13])[CH3:14])[CH:7]=1

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 666654561-(5-Bromo-2-fluorophenyl)-3-(tert-butyldimethylsilyloxy)-2,2-difluoropropan-1-ol

Product 1

HCID 666657711-(5-Bromo-2-fluorophenyl)-3-(tert-butyldimethylsilyloxy)-2,2-difluoropropan-1-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A mixture of 1-(5-bromo-2-fluorophenyl)-3-(tert-butyldimethylsilyloxy)-2,2-difluoropropan-1-ol (19.0 g, mmol) and Pyridinium dichromate (90.0 g, 239.2 mmol) in Dichloromethane (200 mL) was refluxed for 16 h under constant stirring. The catalyst was filtered through a pad of celite and the filtrate was concentrated under reduced pressure to obtain brown colored thick mass. Crude product was purified by column chromatography on silica gel with 1% ethyl acetate in Hexane to obtain title compound as colorless oil. Yield=17.0 g (90%). TLC (10% ethyl acetate in Hexane): Rf=0.56),

Workup

  1. temperaturewas refluxed for 16 h under constant stirring
  2. filtrationThe catalyst was filtered through a pad of celite
  3. concentrationthe filtrate was concentrated under reduced pressure
  4. customto obtain brown colored thick mass
  5. customCrude product was purified by column chromatography on silica gel with 1% ethyl acetate in Hexane

Sources & evidence

ORD record
ord-3c519d6656f147b38178b4dfc0a6a869
Source dataset
uspto-grants-2012_06
Patent number
US08207164B2

Reaction notes

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