4-hydroxycoumarin

Patent Pending 4-Hydroxycoumarins are a class of vitamin K antagonist (VKA) anticoagulant drug molecules derived from coumarin (chromen-2-one) by adding a hydroxy group at the 4 position to obtain "4-hydroxycoumarin" (or "4-hydroxychromen-2-one"; formally then renumbered as 2-hydroxychromen-4-one), then adding a large aromatic substituent at the 3-position (the ring-carbon between the hydroxyl and the carbonyl). The large 3-position substituent is required for anticoagulant activity.