| 摘要 |
<p>PURPOSE:To separate alpha-oxyisobutyric acid selectively, by adding an extracting medium to a solution of a reaction product comprising alpha-oxyisobutyric acid and acidic ammonium sulfate obtained by reacting acetoethydrin with sulfuric acid and water followed by hydrolysis. CONSTITUTION:An extracting medium is added to a solution of a reaction product comprising alpha-oxyisobutyric acid and acidic ammonium sulfate obtained by reacting acetocyanohydrin with sulfuric acid and water, followed by hydrolysis, alpha-oxyisobutyric acid is extracted into an extracting medium phase, and the acidic ammonium sulfate is left in an aqueous phase, to separate alpha-oxyisobutyric acid selectively. When free sulfuric acid remains in the solution of a reaction product, an alkali and the extracting medium are added to the solution and the free sulfuric acid is neutralized during the process. In the extraction, the solution of the reaction product is fed from approximately the middle plate of an extracting column, the extracting medium is fed from the bottom of the column, water or an alkali aqueous solution is fed from the top concentrating part, and countercurrent extraction is carried out. EFFECT:Useful as a raw material for preparing methacrylic acid industrially in high yield.</p> |
