Sodium hydride → 7-Bromo-3,4-dihydro-1-benzoxepin-5(2H)-one

HRID 1498057Notes

Reaction equation

HRID 1498057 reaction equation
[H-].[Na+].[Br:3][C:4]1[CH:5]=[CH:6][C:7]([O:13][CH2:14][CH2:15]Br)=[C:8]([C:10](=[O:12])[CH3:11])[CH:9]=1>C1COCC1>[Br:3][C:4]1[CH:5]=[CH:6][C:7]2[O:13][CH2:14][CH2:15][CH2:11][C:10](=[O:12])[C:8]=2[CH:9]=1

Participants

4

Reactant 2

HCID 24758Sodium hydrideHCID 582041051-[5-Bromo-2-(2-bromoethoxy)phenyl]ethanone

Product 1

HCID 106815487-Bromo-3,4-dihydro-1-benzoxepin-5(2H)-oneYield 70%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a slurry of NaH (60% dispersion in mineral oil) (1.48 g, 37.1 mmol) in THF (˜50 mL) at room temperature was added 1-(5-bromo-2-(2-bromoethoxy)phenyl)ethanone (8.07 g, 25.1 mmol). The reaction mixture was slowly heated to reflux and allowed to stir for 20 h. The solvent was removed under vacuum pressure and the concentrated residue was absorbed onto silica gel and purified by column chromatography (4:1 ethyl acetate/petroleum ether). The product was afforded as a yellow oil after the solvents were removed, providing 4.22 g (70%) of 7-bromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one. 1H NMR (CDCl3) 7.87 (d, J=2.6 Hz, 1H), 7.50 (dd, J=2.6, 8.1 Hz, 1H), 6.97 (d, J=8.8 Hz, 2H), 4.24 (t, J=6.6 Hz, 2H), 2.89 (t, J=7.0 Hz, 2H), 2.15-2.29 (m, 2H).

Workup

  1. temperatureThe reaction mixture was slowly heated
  2. temperatureto reflux
  3. customThe solvent was removed under vacuum pressure
  4. customthe concentrated residue was absorbed onto silica gel
  5. custompurified by column chromatography (4:1 ethyl acetate/petroleum ether)
  6. customThe product was afforded as a yellow oil after the solvents
  7. customwere removed

Sources & evidence

ORD record
ord-eff4740c8f3f4a46b066d6d95c50a45a
Source dataset
uspto-grants-2015_12
Patent number
US09198918B2

Reaction notes

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