Methanol → Methyl alpha-(2-bromomethylphenyl)but-2-enoate

HRID 488021Notes

Reaction equation

HRID 488021 reaction equation
B(Br)(Br)[Br:2].CO[CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[C:14](=[CH:19][CH3:20])[C:15]([O:17][CH3:18])=[O:16].CO.O>C(Cl)Cl>[Br:2][CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[C:14](=[CH:19][CH3:20])[C:15]([O:17][CH3:18])=[O:16]

Participants

6

Reactant 4

HCID 887MethanolHCID 962WaterHCID 25134Boron tribromideHCID 54268689Methyl alpha-(2-methoxymethylphenyl)-beta-methylacrylate

Product 1

HCID 54488747Methyl alpha-(2-bromomethylphenyl)but-2-enoate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

At 0° C., 105.3 ml (140 mmol) of a 1.33 M boron tribromide solution in methylene chloride was dripped into 31 g (140 mmol) of methyl α-(2-methoxymethylphenyl)-β-methylacrylate in 500 ml of CH2Cl2, and the mixture was refluxed for 2 hours. 25 ml of methanol was then added, the mixture was stirred for a further 90 minutes at room temperature, hydrolyzed with water while cooling with ice, and washed neutral with 3% strength caustic solution, and the aqueous phase was extracted with methylene chloride. The combined organic phases were washed with water, dried and evaporated down. The crystals which precipitated were separated off, washed with a small amount of n-hexane and dried. The filtrates were evaporated down end purified chromatographically in a silica gel column (cyclohexane/MTBE:8/1). A total of 31 g of product was obtained in the form of pale yellow crystals.

Workup

  1. customAt 0° C.
  2. temperaturethe mixture was refluxed for 2 hours
  3. temperaturewhile cooling with ice
  4. washwashed neutral with 3% strength caustic solution
  5. extractionthe aqueous phase was extracted with methylene chloride
  6. washThe combined organic phases were washed with water
  7. customdried
  8. customevaporated down
  9. customThe crystals which precipitated
  10. customwere separated off
  11. washwashed with a small amount of n-hexane
  12. customdried
  13. customThe filtrates were evaporated down end
  14. custompurified chromatographically in a silica gel column (cyclohexane/MTBE:8/1)

Sources & evidence

ORD record
ord-c0dbe031db41484482167f0827185fe9
Source dataset
uspto-grants-1994_03
Patent number
US05298527

Reaction notes

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