钯催化羰基化合成丙二酸二乙酯

Palladium Catalyzed Carbonylation of Ethyl Chloroacetate for Synthesis of Diethyl Malonate

以Pd(Ph3P)4为催化剂, 在相转移条件下, 高产率地合成了丙二酸二乙酯。讨论了温度、碱的种类与浓度、催化剂及相转移催化剂对丙二酸二乙酯收率的影响。通过对常压下反应动力学数据的分析,得出该反应为准一级反应,求得了常压下的反应动力学方程和表观活化能,并提出可能的反应机理。

The palladium complex, Pd(Ph3P)4, was used as catalyst in the carbonylation of ethyl chloroacetate for the synthesis of diethyl malonate under the mild conditions. High yield of diethyl malonate, 92.5%, was achieved in the presence of phase transfer catalyst (Bu4NI). The effects of reaction parameters, such as reaction temperature, types of phase transfer agent and kinds of bases as well as the dosage of catalyst on the yields of diehtyl malonate were discussed. The results showed that under atmospheric pressure the optimum reaction temperature was 70℃ and the optimum mole ratio of Bu4NI to reaction substrate was 1:15. Among five kinds of alkaline reagents, NaHCO3 exhibited the most efficient. The reaction rate of carbonylation was enhanced with the increase of the dosage of catalyst. The kinetic studies indicated that this carbontlation reaction showed a pseudo-first-order reaction under the condition of excess of ethanol and carbon monoxide. The apparent kinetic equation was deduced and the apparent activation energy was also determined from the Arrhenius plot. Meanwhile a possible reaction mechanism was proposed.