Water → Ethyl 5-chloro-3-hydroxy-1-benzofuran-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

12.3 g (0.11 mol) of potassium tert.-butylate were added in portions to a solution of 28.6 g (0.1 mol) of (2-carbethoxy-4-chlorophenoxy)-acetic acid ethyl ester in 50 ml of ethanol. The batch was warmed to 80° C. for 2 hours and was then cooled, and the reaction mixture was poured into 200 ml of water. The aqueous solution was first extracted with methylene chloride (to remove neutral impurities) and was then acidified with hydrochloric acid while cooling with ice. The acid solution was repeatedly extracted with methylene chloride. The combined organic extracts were dried over sodium sulfate and then concentrated. 21 g (87.5% of theory) of 2-carbethoxy-5-chloro-3-hydroxy-benzofuran were obtained in the form of colorless crystals of melting point 100°-102° C.

Provenance & Evidence