Hydrochloric Acid → 4'-Vinyl-3-hydroxyflavone

Participants

Reaction Steps

13 gms of 4-vinyl benzaldehyde 0.955 moles) was added to a flask containing 13.9 gms of 2-hydroxyacetophenone (0.955) in 150 ml alcohol. In a separate RB flask, 13 gms of NaOH was dissolved in 100 ml of aqueous ethyl alcohol (75%). The NaOH solution was added to the reaction mixture at once. The color of the solution immediately changed from colorless to yellow to pink, and then, finally, to a dark red precipitate. The solution was allowed to sit at room temperature overnight. The next morning, 6 gms of NaOH in 200 ml of aqueous ethyl alcohol (75%) was added to the Precipitate and the reaction mixture was cooled in an icebath for 15 mins. In a separate RB flask, a solution of 50 ml of 30% hydrogen peroxide solution in 50 ml of aqueous ethyl alcohol (75%) was added to the reaction flask at once at 0°-5° C. The red colored precipitate dissolved immediately and the color of the solution slowly changed from red to yellow. The solution was gradually warmed to room temperature and was stirred for 6 hrs. The reaction mixture was neutralized with dil. HCl at 0°-4° C. A white precipitate formed and was filtered and washed with distilled water until it was free from acid. The color of the product slowly changed from colorless to light pink or to light brown during filtration.

Provenance & Evidence