Liquid 2-hydroxy-4-methylthiobutyric acid and process for the preparation thereof
First Claim
1. A process for the preparation of 2-hydroxy-4-methylthiobutyric acid having improved color, odor and lower viscosity, comprising the steps ofhydrolyzing 2-hydroxy-4-methylthiobutyronitrile with sulfuric acid having an initial strength of betwen about 50% by weight and about 70% by weight on an organic-free basis, thereby producing an intermediate aqueous hydrolysis product solution containing 2-hydroxy-4-methylthiobutyramide;
- hydrolyzing said 2-hydroxy-4-methylthiobutyramide with sulfuric acid having a strength of between about 30% by weight and about 50% by weight on an organic-free basis, thereby producing an aqueous hydrolyzate solution containing 2-hydroxy-4-methylthiobutyric acid;
contacting said hydrolyzate solution with a substantially water-immiscible organic solvent in a liquid/liquid extraction system to produce an extract comprising said solvent and 2-hydroxy-4-methylthiobutyric acid transferred from said hydrolyzate; and
recovering said 2-hydroxy-4-methylthiobutyric acid from said extract in the presence of about 5% or more by weight water based on the amount of recovered 2-hydroxy-4-methylthiobutyric acid.
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Accused Products
Abstract
A process for the preparation of 2-hydroxy-4-methylthiobutyric acid having improved color, odor and lower viscosity. 2-hydroxy-4-methylthiobutyric acid which is also known as 2-hydroxy-4-(methylthio) butanoic acid, is hydrolyzed with sulfuric acid having an initial strength of between about 50% by weight and about 70% by weight on an organic-free basis, thereby producing an intermediate aqueous hydrolysis product solution containing 2-hydroxy-4-methylthiobutyramide. The 2-hydroxy-4-methylthiobutyramide is hydrolyzed with sulfuric acid having a strength of between about 30% by weight and about 50% by weight on an organic-free basis to produce an aqueous hydrolyzate containing 2-hydroxy-4-methylthiobutyric acid. The hydrolyzate solution is contacted with a substantially water-immiscible organic solvent in a liquid-liquid extraction system to produce an extract comprising the solvent and 2-hydroxy-4-methylthiobutyric acid transferred from the hydrolyzate. The acid product is then recovered from the extract.
44 Citations
24 Claims
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1. A process for the preparation of 2-hydroxy-4-methylthiobutyric acid having improved color, odor and lower viscosity, comprising the steps of
hydrolyzing 2-hydroxy-4-methylthiobutyronitrile with sulfuric acid having an initial strength of betwen about 50% by weight and about 70% by weight on an organic-free basis, thereby producing an intermediate aqueous hydrolysis product solution containing 2-hydroxy-4-methylthiobutyramide; -
hydrolyzing said 2-hydroxy-4-methylthiobutyramide with sulfuric acid having a strength of between about 30% by weight and about 50% by weight on an organic-free basis, thereby producing an aqueous hydrolyzate solution containing 2-hydroxy-4-methylthiobutyric acid; contacting said hydrolyzate solution with a substantially water-immiscible organic solvent in a liquid/liquid extraction system to produce an extract comprising said solvent and 2-hydroxy-4-methylthiobutyric acid transferred from said hydrolyzate; and recovering said 2-hydroxy-4-methylthiobutyric acid from said extract in the presence of about 5% or more by weight water based on the amount of recovered 2-hydroxy-4-methylthiobutyric acid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A liquid phase animal feed supplement comprising between about 80% and about 95% by weight of the total of weight proportions of 2-hydroxy-4-methylthiobutyric acid monomer, dimers, and oligomers, and between about 5% and about 20% by weight water, and having a color of not greater than about 10 as measured on the Gardner scale, a ratio of the weight proportions of monomer to the weight proportions of the sum of dimers and other oligomers of about 2.8 or more, a kinematic viscosity at 25°
- C. as measured by a Cannon-Fenske viscometer of not greater than about 90 centistokes, and which, upon subjection to accelerating rate calorimetry exhibits neither exothermic nor endothermic thermochemical effects at any temperature less than about 150°
C.
- C. as measured by a Cannon-Fenske viscometer of not greater than about 90 centistokes, and which, upon subjection to accelerating rate calorimetry exhibits neither exothermic nor endothermic thermochemical effects at any temperature less than about 150°
Specification