Azobisisobutyronitrile → (E)-Ethyl 4-bromo-3-(1-ethoxycarbonylcyclopropyl)-2-fluoro-2-butenoate

HRID 1954634Notes

Reaction equation

HRID 1954634 reaction equation
[CH2:1]([O:3][C:4]([C:6]1([C:9]([CH3:17])=[C:10]([F:16])[C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH2:8][CH2:7]1)=[O:5])[CH3:2].[Br:18]N1C(=O)CCC1=O.N(C(C)(C)C#N)=NC(C)(C)C#N>C(Cl)(Cl)Cl>[Br:18][CH2:17]/[C:9](/[C:6]1([C:4]([O:3][CH2:1][CH3:2])=[O:5])[CH2:8][CH2:7]1)=[C:10](/[F:16])\[C:11]([O:13][CH2:14][CH3:15])=[O:12]

Participants

5

Reactant 3

HCID 6547AzobisisobutyronitrileHCID 67184N-bromobutanimideHCID 54159932Ethyl 3-(1-ethoxycarbonylcyclopropyl)-2-fluoro-2-butenoate

Product 1

HCID 11688379(E)-Ethyl 4-bromo-3-(1-ethoxycarbonylcyclopropyl)-2-fluoro-2-butenoateYield 49.8%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a solution of ethyl 3-(1-ethoxycarbonylcyclopropyl)-2-fluoro-2-butenoate (152.78 g, 0.625 mol) in chloroform (1500 ml) were added N-bromosuccinimide (111.33 g, 0.625 mol) and a catalytic amount of 2,2'-azobis-(isobutyronitrile) and then the resultant mixture was heated under reflux for 16 hours. Then, the liquid reaction mixture was cooled and concentrated under reduced pressure. After adding benzene (300 ml), insoluble matter was filtered off and the filtrate was concentrated under reduced pressure. The residue was subjected to flash silica gel column chromatography (eluent:n-hexane:ethyl acetate=4:1) to obtain 100.5 g (49.7%) of the title compound as a yellow oily substance. On the other hand, 75 g (37.1%) of (Z)-ethyl 4-bromo-3-(1-ethoxycarbonylcyclopropyl)-2-fluoro-2-butenoate (the geometrical isomer of the title compound) was obtained as a yellow oily substance with the use of another eluent (n-hexane:ethyl acetate=2:1).

Workup

  1. temperatureunder reflux for 16 hours
  2. customThen, the liquid reaction mixture
  3. temperaturewas cooled
  4. concentrationconcentrated under reduced pressure
  5. additionAfter adding benzene (300 ml), insoluble matter
  6. filtrationwas filtered off
  7. concentrationthe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-15b413d436db46a59fc1868cea96a4d5
Source dataset
uspto-grants-2000_09
Patent number
US06121285

Reaction notes

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