3-Bromobenzyl bromide → 1-Bromo-3-(but-3-en-1-yl)benzene

HRID 921207Notes

Reaction equation

HRID 921207 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH2:8]Br)[CH:3]=1.[CH2:10]([Mg]Br)[CH:11]=[CH2:12]>C1COCC1>[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH2:8][CH2:12][CH:11]=[CH2:10])[CH:3]=1

Participants

4

Reactant 2

HCID 699793-Bromobenzyl bromideHCID 178455850HCID 178455850, compound

Product 1

HCID 157251651-Bromo-3-(but-3-en-1-yl)benzeneYield 83%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A mixture of 1-bromo-3-(bromomethyl)benzene (1 g, 4.00 mmol) in THF (15 mL) was added allylmagnesium bromide (4.80 mL, 4.80 mmol) and stirred at rt for 1 h, then refluxed for 2 h. It was then quenched with NH4Cl, extracted with EtOAc. The organic layer was dried over MgSO4, filtered and concentrated to obtain an oil. It was then purified by 5% EtOAc/hexane to isolate 1-bromo-3-(but-3-en-1-yl)benzene (0.7 g, 3.32 mmol, 83% yield) as an oil. 1H NMR (400 MHz, CDCl3) δ 7.41-7.31 (m, 2H), 7.21-7.12 (m, 2H), 5.85 (ddt, J=17.1, 10.3, 6.6 Hz, 1H), 5.14-4.94 (m, 2H), 2.75-2.64 (m, 2H), 2.45-2.31 (m, 2H).

Workup

  1. temperaturerefluxed for 2 h
  2. customIt was then quenched with NH4Cl
  3. extractionextracted with EtOAc
  4. dry with materialThe organic layer was dried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto obtain an oil
  8. customIt was then purified by 5% EtOAc/hexane

Sources & evidence

ORD record
ord-e1b2300de3c445f3b3b0e10b03029053
Source dataset
uspto-grants-2016_03
Patent number
US09273067B2

Reaction notes

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