Hydrochloric Acid → Luteolin

Participants

Reaction Conditions

Reaction Steps

3.5 g of isoquercetin are carefully suspended in 500 ml of demineralized water at 60° C., and 8.8 ml of 32% strength aqueous sodium hydroxide solution are introduced into the resulting yellow suspension. During this addition, a dark-red colored clear solution forms. 25 g of sodium d-thionite are added at 60° C. and the mixture is stirred for 12 h at this temperature. The mixture is then cooled to 5° C. and carefully neutralized with 37% strength hydrochloric acid, the solution immediately turning cloudy. The mixture is stirred for 1 h at 0° C. Customary work-up gives 2.05 g of luteolin with a purity of 98.8%.

Provenance & Evidence