Methanol → Methyl 5-chlorothiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-chloro-2-thiophenecarboxylic acid (10 g, 61.5 mmol) in methanol (200 ml) was added sulfuric acid (0.983 ml, 18.45 mmol). The resulting solution stirred at 50° C. overnight. 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 5-chloro-2-thiophenecarboxylate (7.2 g, 40.8 mmol, 66.3% yield): LCMS (ES) m/z 178 (M+H)+.

Provenance & Evidence