33433-82-8Relevant articles and documents
Divalproex sodium method for the recovery and use of the crystallization mother liquor
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Paragraph 0070; 0071, (2017/02/24)
The invention provides a recycling method of divalproex sodium crystallization mother liquor. The method comprises the following steps: 1) concentrating the divalproex sodium crystallization mother liquor to obtain a solid-state mixture containing divalproex sodium; 2) mixing the solid-state mixture obtained in the step 1) with an alkaline solution to dissolve the solid-state mixture to further obtain a mixed solution; 3) mixing the mixed solution obtained in the step 2) with an inorganic salt to produce a valproate precipitate, and separating to obtain the valproate precipitate; 4) mixing the valproate precipitate obtained in the step 3) with an acid solution to obtain an organic layer, and performing fractionation on the organic layer to obtain valproic acid. Through the method provided by the invention, the yield of obtained valproic acid can be as high as 93%, the purity is not lower than 99.6%, and valproic acid can meet medicinal requirements; the method provided by the invention has the advantages of simplicity, easiness in operation, easiness in control of reaction process and effect of reducing actual production cost, and is in line with requirements of industrial mass production.