原釜羰基合成丙二酸二乙酯

在反应釜中，加入铁锰合金粉，氯化钴，硫代硫酸钠，乙醇及通入CO气体，制备四羰基钴钠。接着在同一反应釜中，加入氯乙酸乙酯及溶剂，合成了丙二酸二乙酯。该法极大地简化了生产工艺。

Synthesis of Diethyl Malonate in Situ

A powder of Fe-Mn alloy with cobalt chloride was fed in a reactor, and sodium thiosulfate and alcohol were added after carbon monoxid was introduced to synthesis sodium tetracarbonylcobaltate which was the catalyst of the following diethyl malonate syntheses in situ. Then methylbenzene was added and carbonylation of ethyl chloroacetate was followed to produce diethyl malonate(DEM) in the same reactor. For preparing catalyst , on pressure 1.5MPa, the optimal temperature is about 333K and the optimal reaction time is about 3hr . The synthesis of DEM is conducted according to the table of three factors and three level crisscross test . On the optimal condition of 363K , 1.6MPa , the molar ratio of ClCHCOOC2H5 : CH3CH2OH 1:3.7 and reaction time 5hr , the yield of DEM is about 95% .This process really simplifies the production of diethyl malonate.