Bromine → Ethyl 5-bromothiophene-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

20 g (147 mmol) of aluminum chloride are added portionwise to a solution of 10 g (67 mmol) of ethyl thiophene-3-carboxylate in 160 ml of dichloromethane, cooled beforehand to 0° C. The reaction medium is warmed to room temperature and a solution of 4 ml (73 mmol) of bromine in 10 ml of dichloromethane is then added. After reaction for 50 minutes at room temperature, the reaction medium is poured into a water+ice mixture and extracted with dichloromethane. The organic phase is dried over magnesium sulfate, filtered and evaporated under vacuum. The residue obtained is purified by chromatography on a column of silica eluted with a 9/1 heptane/ethyl acetate mixture. 9 g (57%) of ethyl 5-bromothiophene-3-carboxylate are obtained.

Provenance & Evidence