Dimethylformamide → Benzaldehyde, 2-(3-butenyl)-

HRID 921197Notes

Reaction equation

HRID 921197 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[CH2:8][CH2:9][CH:10]=[CH2:11].[Li]CCCC.CN(C)[CH:19]=[O:20]>C1COCC1>[CH2:8]([C:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[CH:19]=[O:20])[CH2:9][CH:10]=[CH2:11]

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 34857122-(But-3-en-1-yl)bromobenzeneHCID 178418339Butyllithium

Product 1

HCID 10261375Benzaldehyde, 2-(3-butenyl)-Yield 92.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a mixture of 1-bromo-2-(but-3-en-1-yl)benzene (1 g, 4.74 mmol) in THF (10 mL) at −78° C. was added BuLi (2.274 mL, 5.68 mmol) dropwise. It was then stirred at this temperature for 1 h, then N,N-dimethylformamide (0.416 g, 5.68 mmol) was added. The reaction was stirred at 78° C. for 30 min, then warmed to rt and stirred at rt for 1 h. It was then quenched with NH4Cl, extracted with ether. The organic layer was then dried over MgSO4, filtered and concentrated. The residue was purified by biotage, eluting with 10% EtOAc/hexane to obtain 2-(but-3-en-1-yl)benzaldehyde (0.7 g, 92%) as an oil. 1H NMR (400 MHz, CDCl3) δ 10.35-10.26 (m, 1H), 7.86 (dd, J=7.6, 1.5 Hz, 1H), 7.54 (td, J=7.5, 1.6 Hz, 1H), 7.44-7.38 (m, 1H), 7.30 (d, J=8.1 Hz, 1H), 5.95-5.83 (m, 1H), 5.09-5.00 (m, 2H),), 3.20-3.12 (m, 2H), 2.44-2.36 (m, 2H).

Workup

  1. stirringThe reaction was stirred at 78° C. for 30 min
  2. stirringstirred at rt for 1 h
  3. customIt was then quenched with NH4Cl
  4. extractionextracted with ether
  5. dry with materialThe organic layer was then dried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was purified by biotage
  9. washeluting with 10% EtOAc/hexane

Sources & evidence

ORD record
ord-e27700a3db974338b81185866d2d5676
Source dataset
uspto-grants-2016_03
Patent number
US09273067B2

Reaction notes

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