METHOD OF SYNTHESIS OF 2-HYDROXY-4-METHYLTHIO-BUTANOIC ACID Russian patent published in 2002 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to a method of synthesis of 2-hydroxy-4-methylthiobutanoic acid. Method involves carrying out a hydration reaction and the following hydrolysis of 2-hydroxy-4-methyl-thiobutyronitrile in reaction system containing 2-hydroxy-4-methyl-thiobutyronitrile and sulfuric acid where ammonium bisulfate is added during hydration and/or hydrolysis. Then method involves isolation of 2- hydroxy-4-methylthiobutanoic acid from the obtained organic layer, addition of an organic solvent mixing with water to by-side an aqueous layer in order to precipitate ammonium sulfate followed by separation and removal of ammonium sulfate. It ensures to recirculate and use ammonium bisulfate again, decrease consumption of sulfuric acid used, eliminate sulfate-containing sewage practically, decrease manufacture expenditures and avoid the environment pollution. EFFECT: improved method of synthesis, decreased cost, improved ecology. 4 cl, 8 tbl, 2 dwg