Bromide ion → 1-Fluoro-4-nitro-2-(prop-1-en-2-yl)benzene

HRID 1963740Notes

Reaction equation

HRID 1963740 reaction equation
[CH3:1][Si]([N-][Si](C)(C)C)(C)C.[K+].[Br-].[F:12][C:13]1[CH:18]=[CH:17][C:16]([N+:19]([O-:21])=[O:20])=[CH:15][C:14]=1[C:22](=O)[CH3:23]>C1(C)C=CC=CC=1.C1COCC1>[F:12][C:13]1[CH:18]=[CH:17][C:16]([N+:19]([O-:21])=[O:20])=[CH:15][C:14]=1[C:22]([CH3:23])=[CH2:1]

Participants

6

Reactant 3

HCID 259Bromide ionHCID 27810671-(2-Fluoro-5-nitrophenyl)ethan-1-oneHCID 3251421Potassium bis(trimethylsilyl)amide

Product 1

HCID 600980171-Fluoro-4-nitro-2-(prop-1-en-2-yl)benzene

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

KHMDS (1 eq) in toluene is added dropwise over 5 minutes to a stirred suspension of triphenylphosphinemethyl bromide (1.2 eq) in THF at −78° C. under nitrogen. After complete addition solution is allowed to warm to room temperature for 5 minutes then cooled a second time to 78° C. 1-(2-fluoro-5-nitrophenyl)ethanone (1 eq) in THF is then added via cannulla into the cold suspension over 10 minutes. Resulting mixture is then allowed to warm to room temperature and stirred for 1 h. Solvent is then removed under reduced pressure, cyclohexane is then added and mixture heated briefly to reflux, cooled to room temperature, filtered and filtrate concentrated. Crude product is purified using flash chromatography (85% Hex:15% EtoAc) on silica to afford 1-fluoro-4-nitro-2-(prop-1-en-2-yl)benzene.

Workup

  1. temperaturethen cooled a second time to 78° C
  2. customResulting mixture
  3. temperatureto warm to room temperature
  4. customSolvent is then removed under reduced pressure, cyclohexane
  5. additionis then added
  6. temperaturemixture heated briefly
  7. temperatureto reflux
  8. temperaturecooled to room temperature
  9. filtrationfiltered
  10. concentrationfiltrate concentrated
  11. customCrude product is purified

Sources & evidence

ORD record
ord-9dfe576ed9b3470a886442a91dd869fc
Source dataset
uspto-grants-2013_04
Patent number
US08415382B2

Reaction notes

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