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

Participants

Reaction Steps

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.

Provenance & Evidence