Hydrazine hydrate (1:1) → 2,3-Dihydro-1-benzofuran-6-ol

Participants

Reaction Steps

6-Hydroxycoumaran-3-one (15 g) was suspended in ethanol (75 ml) and hydrazine hydrate (10 ml, 90%) was added and the mixture heated at reflux for 1 hour. The solvent was evaporated and a solution of potassium hydroxide (15 g) in ethylene glycol (100 ml) was added to the residue. The resulting mixture was distilled with stirring until the internal temperature reached 185°-190° C. This temperature was maintained until no more nitrogen was evolved, approximately 1.5 hours. After cooling, the mixture was added to dilute hydrochloric acid containing sufficient acid to make the mixture acidic. This acidified mixture was then extracted with ether, dried and distilled (110°-120° C./0.75 mm) to give 6-hydroxy-2,3-dihydrobenzofuran.

Provenance & Evidence