Synthesis and pharmacological properties of a phthalide derivative containing methoxy groups

4,6-Dimethoxy-5-hydroxyphthalide 2 was obtained on three routes: by selective demethylation of 4,5,6-trimethoxyphthalide and by the action of formaldehyde on either syringic acid or acetylsyringic acid. Pharmacological tests carried out on rats showed that the product significantly increased bile excretion, its activity being five times higher than those of dehydrocholic acid.