Process for purifying noroxymorphone compounds

Abstract

A process for purifying plant extracts which consist essentially of noroxymorphone compounds and which comprise, as impurities, α,β-unsaturated noroxymorphone compounds, by (a) converting the plant extract or the product of a subsequent stage in the synthesis of a selected noroxymorphone compound in a reaction which converts the hydroxyl groups present in the mixture to leaving groups of the formula —ORin which Ris the introduced radical of the leaving group, (b) these leaving groups are optionally detached again, then (c) the resulting mixture is subjected to a selective hydrogenation, so that a saturated bond is formed in the α,β-position of the unsaturated noroxymorphone compounds and any remaining leaving groups are each converted to a hydroxyl group and then optionally (d) the pure noroxymorphone compound is isolated; processing of the noroxymorphone purified in this way to naltrexone or naloxone or a salt of these compounds or a quaternary derivative of these compounds; pharmaceutical formulations comprising such a compound.