[Synthesis of isoflavones as cardiovascular drug]

On the basis of the chemical structure of daidzein, a series of isoflavones have been synthesized. The intermediates, 7-methoxy-4'-hydroxy-isoflavone(V) and 7-hydroxy-4'-methoxyisoflavone(IX) were prepared by condensation of corresponding desoxybenzoin with dimethylformamide dimethylacetal. 7-Methoxy-2-methyl-4'-hydroxyisoflavone (VII) was also prepared from desoxybenzoin IV by reacting with acetic anhydride and anhydrous sodium acetate and followed by hydrolysis. Compounds I1-5 were obtained by Mannich reaction and compounds II1,2 III1,2 were obtained by etherification of corresponding isoflavones. All compounds were tested for resistance to hypoxia in mice and I1-3, I5, II1 and III2 were shown to have significant effect. Compound I1 and I5 were also found to increase coronary blood flow.