Condensation reactions in water of active methylene compounds with arylaldehydes. One-pot synthesis of flavonols

Article abstract of DOI:10.1016/S0040-4020(01)89287-5

The condensation reactions of acetophenone, cyclohexanone, isophorone, phenylacetonitrile, p-nitrophenylacetonitrile, (phenylsulfonyl)acetonitrile and indene with benzaldehyde were studied in water heterogeneous phase in the presence and absence of anionic and cationic surfactants such as SLS, CTACl, (CTA)₂SO₄ and CTAOH. All the reactions occur with excellent yields. The cationic surfactants favour the reaction and the comparison with the corresponding tetrabutylammonium salts show that the micellar catalysis is effective mainly towards the dehydration reaction following that of condensation. Anionic surfactant SLS is inactive. 2'-hydroxychalcones were prepared in aqueous medium in good-excellent yields and the one-pot synthesis of 7- and 3',4'-substituted flavonols was achieved.