| 摘要 |
PURPOSE:To obtain the title compound conveniently in an industrial scale by reacting monohalogenoacetic acid alkyl ester, a lower aliphatic alcohol and CO in the presence of a Co carbonyl catalyst, and decomposing, recovering, and rgenerating the catalyst. CONSTITUTION:A malonic acid dialky ester is prpared by the reaction of monohalogenoacetic acid alkyl ester, a lower aliphatic alcohol and CO in the presence of a Co carbonyl catalyst and a basic substance. The produced solution is treated with an aqueous solution of an inorganic acid to decompose the catalyst. For example, the formed Co inorganic acid salt is extracted to the water layer. The organic liquid layer is distilled to obtaine a pure malonic acid dialkyl ester. The water layer containing the catalyst is treated with an alkali hydroxide aqueous solution to afford a Co hydroxide which is regenerated as the catslyst. EFFECT:The energy of recovery and recycling of the catalyst can be minimized corresponding to the decrease in the amount of the alcohol. The catalyst can be recovered quantitatively. |
