Citric Acid → 5-Hydroxypyridine-2-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 5-hydroxy-pyridine-2-carboxylic acid (1.25 g, 9.0 mmol) in ethanol (40 mL) was added concentrated sulfuric acid (3 mL, 56.3 mmol) and the resulting solution heated at reflux under an atmosphere of argon for 20 h. The solution was then cooled to 0° C. then sodium hydroxide (2 N, 55 mL) was added. Saturated aqueous sodium bicarbonate and 10% w/w citric acid solution were then added to bring the pH to 7 and the resulting solution concentrated to ˜70 mL). The resulting mixture was extracted with ethyl acetate (3×50 mL) and the combined organic extracts dried, filtered and concentrated to afford the title compound (829 mg, 55%) as an off white solid. MS: m/e=168.3 [M+H]+.

Provenance & Evidence