5-Bromo-thiophene-2-carboxylic acid methyl ester

67-56-1

7311-63-9

62224-19-5

General procedure for the synthesis of methyl 5-bromothiophene-2-carboxylate from methanol and 5-bromo-2-carboxythiophene: 950 mg (4.62 mmol) of 5-bromo-2-carboxythiophene was accurately weighed and dissolved in 10 mL of methanol. Under stirring conditions, 2 ml of sulfoxide chloride (SOCl2) was slowly added dropwise to the solution. After completion of the reaction, the reaction mixture was cooled to room temperature. Subsequently, the solvent was removed by evaporation under reduced pressure. The residue was dissolved in an appropriate amount of toluene and dried by evaporation under reduced pressure, this process was repeated three times to completely remove the residual sulfoxide chloride and methanol. The intermediate 5-bromothiophene-2-carboxylic acid methyl ester was finally obtained as 1.0 g in 100% yield.