p-Toluenesulfonic acid → Ethyl 4-bromo-3-oxopentanoate

HRID 2166017Notes

Reaction equation

HRID 2166017 reaction equation
[Br:1]Br.[O:3]=[C:4]([CH2:11][CH3:12])[CH2:5][C:6]([O:8][CH2:9][CH3:10])=[O:7].C1(C)C=CC(S(O)(=O)=O)=CC=1>CCl>[Br:1][CH:11]([CH3:12])[C:4](=[O:3])[CH2:5][C:6]([O:8][CH2:9][CH3:10])=[O:7]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 24408BromineHCID 78656Ethyl 3-oxovalerate

Product 1

HCID 12780443Ethyl 4-bromo-3-oxopentanoate

Reagents, catalysts & solvents 1

HCID 6327Methyl ChlorideSolvent

Procedure

277 g of bromine are added dropwise to a solution of 250 g of ethyl 3-oxovalerate and 0.5 g of p-toluenesulphonic acid in 55 ml of methyl chloride at room temperature, while stirring. The mixture is subsequently stirred at 30° C. for one hour, ice-water is added and the organic phase is separated off. The aqueous phase is extracted once more with methylene chloride and the combined organic phases are then dried over magnesium sulphate and evaporated. The product is further processed in the crude form.

Workup

  1. stirringThe mixture is subsequently stirred at 30° C. for one hour
  2. customthe organic phase is separated off
  3. extractionThe aqueous phase is extracted once more with methylene chloride
  4. dry with materialthe combined organic phases are then dried over magnesium sulphate
  5. customevaporated

Sources & evidence

ORD record
ord-70bb8d441d0643388a5e29553a42b882
Source dataset
uspto-grants-1990_07
Patent number
US04943568

Reaction notes

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