Pyridiniumtribromide → 7-Bromo-5-isobutyl-3,3-dimethyl-2,3-dihydro-benzofuran

HRID 460280Notes

Reaction equation

HRID 460280 reaction equation
[CH2:1]([C:5]1[CH:6]=[CH:7][C:8]2[O:12][CH2:11][C:10]([CH3:14])([CH3:13])[C:9]=2[CH:15]=1)[CH:2]([CH3:4])[CH3:3].[Br-:16].[Br-].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl>[Br:16][C:7]1[C:8]2[O:12][CH2:11][C:10]([CH3:13])([CH3:14])[C:9]=2[CH:15]=[C:5]([CH2:1][CH:2]([CH3:4])[CH3:3])[CH:6]=1

Participants

4

Reactant 2

HCID 21124087PyridiniumtribromideHCID 220413975-Isobutyl-3,3-dimethyl-2,3-dihydro-benzofuran

Product 1

HCID 220414107-Bromo-5-isobutyl-3,3-dimethyl-2,3-dihydro-benzofuranYield 68.5%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 5-isobutyl-3,3-dimethyl-2,3-dihydro-benzofuran (1.59 g, 7.78 mmol) in dichloromethane (40 mL) was added pyridinium tribromide (2.49 g, 7.78 mmol) and the reaction mixture stirred at room temperature overnight. The solution was washed with water and brine, dried (MgSO4), filtered and evaporated. The residue was purified on silica gel (0% to 2% ethyl acetate in hexane) to give 1.51 g of 7-bromo-5-isobutyl-3,3-dimethyl-2,3-dihydro-benzofuran (68%). 1H NMR (300 MHz; CDCl3): δ 0.90 (d, J=6.3 Hz, 6H), 1.33 (s, 6H), 1.77 (m, 1H), 2.39 (d, J=7.5 Hz, 2H), 4.30 (s, 2H), 6.80 (d, J=1.5 Hz, 1H), 7.05 (d, J=1.5 Hz, 1H).

Workup

  1. washThe solution was washed with water and brine
  2. dry with materialdried (MgSO4)
  3. filtrationfiltered
  4. customevaporated
  5. customThe residue was purified on silica gel (0% to 2% ethyl acetate in hexane)

Sources & evidence

ORD record
ord-3ebd96619f584988882e4ef33576ddad
Source dataset
uspto-grants-2007_03
Patent number
US07196108B2

Reaction notes

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