THE SYNTHESIS OF 7, 11, 12-TRIMETHOXYCOUMESTAN
The reaction of 2'-hydroxy-7, 4', 5'-trimethoxyisoflavone with benzyl chloride in the presence of anhydrous potassium carbonate in acetone gave a corresponding 2'-benzyloxyisoflavone. The ring cleavage of the compound with alcoholic alkali gave 2-hydroxy-4-methoxyphenyl 2-benzyloxy-4, 5-dimethoxybenzyl ketone. By the treatment of the ketone with diethyl carbonate and sodium, 4-hydroxy-7- methoxy-3-(2-benzyloxy-4, 5-dimethoxyphenyl) coumarin was obtained. The debenzylation of the coumarin with acid gave a dihydroxycoumarin, and subsequently the intramolecular dehydration in methanol with hydrogen chloride yielded the title compound.