| abstract |
An improved method for preparing succinic acid with consistently high biological activity, inter alia adaptogenic activity, comprising the preparation of a modified palladium-containing catalyst using acid, the liquid-phase hydrogenation of unsaturated acidic compounds on the resultant modified catalyst at elevated temperature and elevated pressure, the removal of the catalyst after hydrogenation, and the isolation of the resultant succinic acid. For the purpose of modification, a pre-prepared palladium-containing catalyst applied to a carrier is used in an oxygen-free atmosphere. Modification is carried out in an aqueous medium of succinic or maleic or fumaric acid and/or a mixture thereof at a mass ratio of Pd2+ : acid = 1 : 1-100, after which the liquid-phase hydrogenation of unsaturated acidic compounds selected from the group consisting of maleic and fumaric acid or anhydrides thereof or mixtures thereof is carried out on the resultant catalyst. The succinic acid resulting from this hydrogenation is isolated by crystallization from an aqueous solution containing 0.001-0.01 mass% of a seeding agent, namely succinic acid with good biological properties. |