Bromine → 4,8-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one

HRID 1190248Notes

Reaction equation

HRID 1190248 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[C:11](=[O:12])[CH2:10][CH2:9][CH2:8][O:7][C:6]=2[CH:13]=1.[Br:14]Br>CCOCC>[Br:14][CH:10]1[CH2:9][CH2:8][O:7][C:6]2[CH:13]=[C:2]([Br:1])[CH:3]=[CH:4][C:5]=2[C:11]1=[O:12]

Participants

4

Reactant 2

HCID 24408BromineHCID 103770258-Bromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one

Product 1

HCID 579002754,8-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-oneYield 102.5%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a stirred solution of 8-bromo-3,4-dihydro-2H-benzo[b]oxepin-5-one (3.10 g; 12.8 mmol) in Et2O at 0° C. was added Br2 (625 μl; 12.2 mmol) and the reaction mixture was allowed to warm to r.t. over 2 h. Volatiles were evaporated and the residue purified by flash column chromatography (0-20% EtOAc in hexanes) to give 4,8-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one as a colorless solid (4.0 g, 96% yield). 1H NMR (400 MHz, CDCl3) δ 7.18-7.21 (m, 2H), 7.55 (d, J=8.0, 1H), 4.87 (app. t, J=5.2, 2H), 4.33-4.39 (m, 1H), 4.09-4.16 (m, 1H), 2.78-2.91 (m, 1H), 2.40-2.49 (m, 1H).

Workup

  1. customVolatiles were evaporated
  2. customthe residue purified by flash column chromatography (0-20% EtOAc in hexanes)

Sources & evidence

ORD record
ord-470a2e0a14c54112a390f716be0a90ac
Source dataset
uspto-grants-2014_03
Patent number
US08673952B2

Reaction notes

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