Acetic Anhydride → HCID 14857385, compound

Participants

Reaction Steps

400 mg of 3-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxide were dissolved in 10 ml of acetic anhydride and heated at reflux for 8 hours. After removal of the solvent by evaporation the residue was dissolved in ethanol and 15 mg of 80% (w/w) sodium hydride were added. After stirring for 30 minutes the mixture was evaporated and the residue was dissolved in a mixture of ethyl acetate and water. The aqueous phase was acidified with dilute hydrochloric acid, extracted with ethyl acetate, then made basic with sodium bicarbonate solution and re-extracted with ethyl acetate. The combined organic extracts were dried over sodium sulphate and evaporated. The residue was chromatographed on silica gel using 8% (v/v) methanol/ethyl acetate for the elution to give 310 mg of 3-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)-2(1H)-pyridone of melting point 196°-197° C. after recrystallization from t-butyl methyl ether.

Provenance & Evidence