METHOD OF SYNTHESIS OF 2-HYDROXY-4-METHYLTHIOBUTYRIC ACID (HYDROXY-ANALOG OF METHIONINE) Russian patent published in 1999 - IPC

FIELD: organic chemistry and technology. SUBSTANCE: invention describes a method of synthesis of 2-hydroxy-4-methylthiobutyric acid where 2-hydroxy-4-methylthiobutyric acid is isolated from reaction mass. The latter is obtained by an addition reaction of hydrocyanic acid to methylmercaptopropionic aldehyde and hydrolysis of methylmercaptopropionic aldehydecyanohydrin formed that is carried out by interaction with sulfuric acid. Reaction mixture is contacted with an organic solvent not mixing with water mainly in an extraction system liquid-liquid to obtain an extraction solution containing a solvent. 2-Hydroxy-4-methyl-thiobutyric acid is extracted from the reaction mixture and 2-hydroxy-4-methylthiobutyric acid is obtained as an extract from this an extraction solution by evaporation. Evaporation is carried out thus that water content in the extract obtained is less 4 wt. -%. Invention describes also hydroxy-analog of an amino acid methionine in racemic form which is an essential addition to animal fodder. EFFECT: increased purity and high concentration of the end product. 8 cl, 6 dwg, 2 tbl, 9 ex