Hydrogen Bromide → 3,9-Dibromo-5,7-dihydrodibenzo[c,e]oxepine

HRID 645419Notes

Reaction equation

HRID 645419 reaction equation
Br.C1COCC1.[Br:7][C:8]1[CH:13]=[CH:12][C:11]([C:14]2[CH:19]=[CH:18][C:17]([Br:20])=[CH:16][C:15]=2[CH2:21]O)=[C:10]([CH2:23][OH:24])[CH:9]=1>CC(C)=O>[Br:20][C:17]1[CH:18]=[CH:19][C:14]2[C:11]3[CH:12]=[CH:13][C:8]([Br:7])=[CH:9][C:10]=3[CH2:23][O:24][CH2:21][C:15]=2[CH:16]=1

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 8028TetrahydrofuranHCID 113721754,4'-Dibromo-2,2'-bis-hydroxymethyl-biphenyl

Product 1

HCID 223161653,9-Dibromo-5,7-dihydrodibenzo[c,e]oxepineYield 51%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

HBr (11 mL, 97 mmol) was added to a THF (10 mL) solution of (4,4′-dibromobiphenyl-2,2′-diyl)dimethanol (for preparation, see: Tetrahedron Letters 2004, 45, 2801; 1.3 g, 3.49 mmol), and the mixture was refluxed for six hours and then allowed to cool to ambient temperature. Most of the organic component was removed with a rotervap, and the residue was extracted with CH2Cl2 (10 mL, 3×). The combined organic phase was dried (MgSO4), filtered, and concentrated in vacuo to afford a brown oil, which when dissolved in 5 mL acetone and allowed to stand at ambient condition for 1 h afforded a precipitate. Filtration and drying in vacuo afforded 3,9-dibromo-5,7-dihydrodibenzo[c,e]oxepine as a white solid (0.628 g, 51% yield). 1H NMR (DMSO-d6, δ=2.5, 500 MHz): 4.23-4.29 (m, 4H), 7.53-7.60 (m, 2H), 7.74 (dd, J=7.9, 2.1, 2H) 7.79 (d, J=2.1, 2H).

Workup

  1. temperaturethe mixture was refluxed for six hours
  2. customMost of the organic component was removed with a rotervap
  3. extractionthe residue was extracted with CH2Cl2 (10 mL, 3×)
  4. dry with materialThe combined organic phase was dried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customto afford a brown oil, which when
  8. customafforded a precipitate
  9. filtrationFiltration
  10. customdrying in vacuo

Sources & evidence

ORD record
ord-354ae66f26984ac6910b04ae2c29be05
Source dataset
uspto-grants-2010_04
Patent number
US07704992B2

Reaction notes

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