Patent ID: 7148379

Claim:
A process for the preparation of 2-hydroxy-4-methylthiobutyric acid, comprising reacting an addition product 2-hydroxy-4-methylthiobutyronitrile obtained by addition of hydrocyanic acid on to 3-methyithiopropionaldehyde with sulfuric acid via an intermediate 2-hydroxy-4-methylthiobutyramide, wherein the reaction of 2-hydroxy-4-methylthiobutyronitrile to give 2-hydroxy-4-methylthiobutyramide and the subsequent conversion to 2-hydroxy-4-methylthiobutyric acid are carried out in reaction containers which are corrosion-resistant for reaction media employed and are manufactured from a corrosion-resistant material which is at least one of alloyed steel and nickel alloys and wherein the corrosion-resistant materials employed have a material loss rate of <0.06 mm p.a. at temperature of 60° or of <0.1 mm p.a. at temperature of 110° C. as measured in accordance with ASTM G4-68.