N-bromobutanimide → Benzyl 4-bromo-but-2-enate

HRID 1417928Notes

Reaction equation

HRID 1417928 reaction equation
[C:1]([O:6][CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)(=[O:5])/[CH:2]=[CH:3]/[CH3:4].[Br:14]N1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl>[Br:14][CH2:4][CH:3]=[CH:2][C:1]([O:6][CH2:7][C:8]1[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1)=[O:5]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 5356259Benzyl crotonate, (E)-

Product 1

HCID 54298885Benzyl 4-bromo-but-2-enate

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of benzyl crotonate (4.0 g, 22.73 mmol) in anhydrous carbon tetrachloride (20 ml) was added N-bromosuccinimide (4.045 g, 22.7 mmol). The resulting suspension was refluxed at 100° C. under nitrogen for 20 minutes. After cooling to room temperature, the solid was removed by filtration. The filtrate was evaporated under reduced pressure to dryness. The oily residue was separated on a flash column (silica, F 4×40 cm), packed with hexane. The column was eluted with 4 liters of 4% ethyl acetate. The desired product was obtained as an oil (510 mg, 9% yield). Rf: 0.4 (10% ether/hexane) 1H NMR (CDCl3): δppm 3.99 (2H, dd, J1=7.4 Hz, J2=1.3 Hz), 5.19 (2H, s), 6.07 (1H, dt, J1=15.3 Hz, J2=1.1 Hz), 7.04 (1H, m), 7.36 (5H, m). 13C NMR (CDCl3): δppm 29.0 (t), 66.5 (t), 124.2 (d), 128.2 (d), 128.3 (d), 128.5 (d), 135.8 (s), 142.2 (d), 165.2 (s).

Workup

  1. temperatureAfter cooling to room temperature
  2. customthe solid was removed by filtration
  3. customThe filtrate was evaporated under reduced pressure to dryness
  4. customThe oily residue was separated on a flash column (silica, F 4×40 cm)
  5. washThe column was eluted with 4 liters of 4% ethyl acetate

Sources & evidence

ORD record
ord-f27e3e19bdf844838b3c1ad012228062
Source dataset
uspto-grants-1999_03
Patent number
US05879894

Reaction notes

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