Phenylacetic Acid → 7-Hydroxyisoflavone

Participants

Reaction Conditions

Reaction Steps

Resorcinol (0.66 g, 6 mmol), phenylacetic acid (0.816 g, 6 mmol), and boron triflouride diethyletherate (5 ml) were heated to 85° C. for 90 mins. After this time the reaction was cooled and DMF (4 ml) was added. 30 min prior to the completion of the first stage, PCl5 (1.878 g, 9 mmol) was added to cool DMF (8 ml) and the mixture heated (60° C.) for 20 minutes. This was added to the solution from stage one, and the combined solution allowed to stir at room temperature for 1 hour. The reaction mixture was then poured into 1MHCl (100 ml). The precipitate formed was filtered and re-crystallized from methanol to give 7-Hydroxy-3-phenyl-chromen-4-one as a white solid (1.3 g, 91.0%); Rf 0.25 ethyl acetate/hexane (30/70)].

Provenance & Evidence