A new substituted coumarin

摘要

6,7 - Dihydroxycoumarin - 4 - methylsulphonic acid and its salts are prepared by heating 6,7-dihydroxy-4-halogenomethylcoumarin with a metal sulphite and converting the metal salt thus obtained into the free acid, another metal salt, or salts with organic bases such as papaverine, aminophylline, vicamine, pyridoxine and ketaine. Therapeutic compositions contain the above novel compounds as the active ingredients. The compositions, which may be administered orally, parenterally, or rectally, are useful in the treatment of capillary permeability or capillary fragility and for protecting oxidizable metabolites and drugs from oxidation in vivo.