Bromine → Methyl 3-bromo-2-methylbenzo[b]thiophene-5-carboxylate

Participants

Reaction Steps

Bromine (2.08 g) was added dropwise to a stirred mixture of 2-methylbenzo[b]thiophene-5-carboxylic acid methyl ester (2.40 g) and anhydrous sodium acetate (2.40 g) in chloroform (50 ml). The mixture was stirred for 2 hours at room temperature and then washed with water, sodium bicarbonate solution and dried (NaSO4). Evaporation of the chloroform gave a solid which was crystallised from methanol/water to give 3-bromo-2-methylbenzo[b]thiophene-5-carboxylic acid methyl ester (2.00 g), m.p. 84°-85°.

Provenance & Evidence