| 摘要 |
PURPOSE:To obtain the titled compound useful as a raw material for pharmaceuticals, agricultural chemicals, etc., with simple operation in high yield, by extracting a synthetic liquid containing a malonic acid diester with water at a specific pH condition, thereby separating the organic phase distinctly from the water phase. CONSTITUTION:A synthetic liquid containing malonic acid diester is separated into an organic phase containing the malonic acid diester and an aqueous phase containing a water-soluble inorganic salt by extracting with water at <=2pH. the synthetic liquid used as the raw material of the process is obtained e.g. by producing a malonic acid diester from a monohalogenoacetic acid alkyl ester by conventional method, contacting the ester with an aqueous solution of an inorganic acid to effect the decomposition of the catalyst used in the above reaction and removing the excess alcohol from the system. The extraction with water is preferably carried out in the presence of a mineral acid such as HCl, H2SO4, etc.
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