Methyl Thioglycolate → Methyl 7-bromobenzo[b]thiophene-2-carboxylate

Participants

Reaction Steps

Under an argon atmosphere, 8.2 g (205.7 mmol) of sodium hydride (60% in liquid paraffin) are introduced into 300 ml of absolute DMSO. At room temperature, 16.0 g (150.9 mmol) of methyl mercaptoacetate are slowly added dropwise to the reaction mixture, which is stirred at room temperature until hydrogen evolution ceases (about 15 min). A solution of 27.8 g (137.1 mmol) of 3-bromo-2-fluorobenzaldehyde in 50 ml of absolute DMSO is added at room temperature to the reaction mixture. The latter is stirred until the reaction is complete and then poured into ice-water. The resulting precipitate is filtered off with suction and dried in vacuo at 40° C. overnight. 20.57 g of a mixture of the title compound and of the corresponding acid (approx. 1:1) are obtained.

Provenance & Evidence