Methanol → Methyl 4-bromo-5-ethylthiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-bromo-5-ethyl-2-thiophenecarboxylic acid (1 g, 4.25 mmol) in methanol (21.27 ml) was added sulfuric acid (0.23 mL, 4.25 mmol). The resulting solution was stirred at 50° C. for 48 h. H2O (50 mL) was added and the reaction was cooled to 0° C. in an ice-bath. The pH was adjusted to ˜12 and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and used directly without further purification providing methyl 4-bromo-5-ethyl-2-thiophenecarboxylate (1.060 g, 4.25 mmol, 100% yield): LCMS (ES) m/e 248, 250 (M, M+2)+.

Provenance & Evidence