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

HRID 1190254Notes

Reaction equation

HRID 1190254 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) δ 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-47ee4e3d6ef1455caa1d164d5b952cb7
Source dataset
uspto-grants-2014_03
Patent number
US08673952B2

Reaction notes

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