Bromine → 4,7-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one

HRID 1498058Notes

Reaction equation

HRID 1498058 reaction equation
[Br:1][C:2]1[CH:13]=[CH:12][C:5]2[O:6][CH2:7][CH2:8][CH2:9][C:10](=[O:11])[C:4]=2[CH:3]=1.[Br:14]Br>CCOCC>[Br:14][CH:9]1[CH2:8][CH2:7][O:6][C:5]2[CH:12]=[CH:13][C:2]([Br:1])=[CH:3][C:4]=2[C:10]1=[O:11]

Participants

4

Reactant 2

HCID 24408BromineHCID 106815487-Bromo-3,4-dihydro-1-benzoxepin-5(2H)-one

Product 1

HCID 579004584,7-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-oneYield 91.9%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To 7-bromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one (3 g, 12 mmol) in ether (110 mL) was added bromine (0.7 mL, 14 mmol) and allowed to stir at room temperature overnight. The reaction mixture was concentrated under reduced pressure and purified via ISCO chromatography (hexane to 20% hexane in EtOAc over 45 minutes). Collected fractions and concentrated to give 4,7-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one (3.53 g, 89%). 1H NMR (500 MHz, CDCl3) δ 7.86 (d, J=2.5, 1H), 7.52 (dt, J=28.5, 14.2, 1H), 6.97 (d, J=8.7, 1H), 4.95 (dd, J=7.6, 6.8, 1H), 4.53-4.36 (m, 1H), 4.17 (ddd, J=12.8, 9.9, 4.4, 1H), 3.04-2.84 (m, 1H), 2.52 (ddt, J=14.7, 7.8, 4.5, 1H)

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. custompurified via ISCO chromatography (hexane to 20% hexane in EtOAc over 45 minutes)
  3. concentrationCollected fractions and concentrated

Sources & evidence

ORD record
ord-2d2cb4bff7f242e29b075b73248c2757
Source dataset
uspto-grants-2015_12
Patent number
US09198918B2

Reaction notes

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