Hydrochloric Acid → 4-Bromo-3-hydroxythiophene-2-carboxylic acid

Participants

Reaction Steps

A mixture of 4-bromothiophene-2-carboxylic acid methyl ester (500 mg, 2.1 mmol), sodium hydroxide (261 mg, 6.3 mmol) in a mixed solvent of methanol/water (2.5 mL+2.5 mL) was refluxed for 2 hours. After the reaction mixture was cooled to room temperature, 2N hydrochloric acid was added to adjust pH to 1, and it was diluted with ethyl acetate. After the ethyl acetate layer was washed successively with water and brine, dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure to give the title compound (326 mg, 69.4%) as a red brown powder.

Provenance & Evidence