Demethylation-Sulfonation of 2',3',4'-Trimethoxyflavones
摘要:
Total demethylation of 2',3',4'-trimethoxyflavones with sulfuric acid was realised at mild temperature giving respective 2',3', 4'-trihydroxyflavone-5'-sulfonic acids. A multi steps mechanism is proposed in the light of earlier results and the complete assignment of the H-1 and C-13 NMR spectra of a suggested 3'-hydroxy-2',4'-dimethoxy intermediate.