Carbon tetrabromide → 4-(2,2-Dibromo-vinyl)-5-methyl-3-phenyl-isoxazole

HRID 1695467Notes

Reaction equation

HRID 1695467 reaction equation
[CH3:1][C:2]1[O:6][N:5]=[C:4]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[C:3]=1[CH:13]=O.[Br:15][C:16](Br)(Br)[Br:17].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>>[Br:15][C:16]([Br:17])=[CH:13][C:3]1[C:4]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)=[N:5][O:6][C:2]=1[CH3:1]

Participants

4

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 27761445-Methyl-3-phenylisoxazole-4-carboxaldehyde

Product 1

HCID 867615574-(2,2-Dibromo-vinyl)-5-methyl-3-phenyl-isoxazoleYield 83%

Procedure

To a stirred solution of 5-methyl-3-phenyl-isoxazole-4-carbaldehyde (5.20 g, 27.8 mmol) was added tetrabromomethane (12.9 g, 38.9 mmol) and then triphenylphosphine (14.57 g, 55.5 mmol) and the resulting mixture stirred under argon for 2 h at 0° C. The solution was concentrated to approximately 90 mL and the resulting precipitate filtered, washed with dichloromethane and discarded. This was repeated until the majority of the triphenylphospine oxide and bromide was removed. Purification by chromatography (silica, heptane:ethyl acetate 9:1 to 2:3) afforded the title compound (7.9 g, 83%) which was obtained as a colorless oil. MS: m/e=344.0 [M+H]+.

Workup

  1. concentrationThe solution was concentrated to approximately 90 mL
  2. filtrationthe resulting precipitate filtered
  3. washwashed with dichloromethane
  4. customwas removed
  5. customPurification by chromatography (silica, heptane:ethyl acetate 9:1 to 2:3)

Sources & evidence

ORD record
ord-4429e26dd5184aa0a81320cae45a4a51
Source dataset
uspto-grants-2012_04
Patent number
US08163728B2

Reaction notes

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