Hydrochloric Acid → 7-CHLOROTHIENO[3,2-B]PYRIDINE-6-CARBOXYLIC ACID

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 7-chlorothieno[3,2-b]pyridine-6-carboxylate (2.98 g, 12.3 mmol) [Thompson, M.; Forbes, I. F. EP 126970] in 40 mL of ethanol and 15 mL of 2.5 N sodium hydroxide is heated at reflux for 1 hour. The mixture is cooled to 0° C. and the pH is adjusted to 4 by the addition of 4 N hydrochloric acid. The mixture is stirred at room temperature and the resulting precipitate is collected by filtration washing with water to provide 2.47 g of 7-chlorothieno[3,2-b]pyridine-6-carboxylic acid as a white solid, 1H NMR (DMSO-d6) δ 7.73 (d, J=6 Hz, 1H), 8.44 (d, J=6 Hz, 1H), 9.07 (s, 1H).

Provenance & Evidence