| 摘要 |
PURPOSE:To prepare the titled compound economically, by carbonylating a monochloroacetic acid ester using an alcohol solution of cobalt tetracarbonyl anion as a catalyst, regenerating the catalyst after decomposition and recovery, and esterifying the reaction by-products. CONSTITUTION:A monochloroacetic acid ester is carbonylated using an alcohol or acetone solution of cobalt tetracarbonyl anion as a catalyst. The catalyst in the produced liquid is decomposed with sulfuric acid and oxygen to obtain cobalt sulfate, which is extracted with water and separated from the organic layer after removing the excess alcohol by distillation. The titled compound is separated from the organic layer by distillation, and a malonic acid monoester existing in the distillation residue is esterified to obtain the titled compound in high yield. The cobalt sulfate produced in the decomposition process is converted to a water-insoluble cobalt compound (e.g. carbonate or hydroxide), recovered from the aqueous layer, and made to react with CO and H2 in the above solvent in the presence of a seed catalyst to regenerate the catalyst. |
