Preparation of Sodium Cobalt Tetracarbonyl and Optimization of Process Conditions for Hydroesterification of Ethylene Oxide

In this paper, sodium cobalt tetracarbonyl （NaCo（CO）4） was synthesized by using sodium dithionite and zinc powder as the reduction system and cobalt hexahydrate acetate as the precursor in the presence of methanol solvent. Methyl 3-hydroxypropionate was synthesized via hydroesterification of ethylene oxide （EO） catalyzed by NaCo（CO）4. The influencing factors on the reaction results were discussed, including the different ligands, the molar ratio of solvent and ethylene oxide, the reaction temperature, the reaction time, and the reaction pressure. An optimal catalytic system was obtained by using 3-hydroxypyridine as the ligoad under reaction conditions covering a reaction temperature 65 ℃, a reaction time of 7 h, a reaction pressure of 6 MPa, and a methoaol/EO molar ratio of 3：2. Under the optimal conditions, the conversion of ethylene oxide was equal to 97.86%, while the selectivity and yield of methyl 3-hydroxypropionate reached 88.19% and 86.30%, respectively. Finally, the reaction mechanism of hydroesterification of ethylene oxide catalyzed by NaCo（CO）4 was proposed.

由氯化钴制备四羰基钴盐的反应动力学

由氯化钴与ＣＯ制备四羰基钴盐是一个多相羰化反应。本文研究了影响反应速度的主要因素。测定了３２３～３４３Ｋ温度范围的动力学数据。根据实验数据得出反应速度方程式为：－ｄ［ＣｏＣｌ２］ｄｔ＝ｋ［ＣｏＣｌ２］［Ｒｅｄ］反应活化能为７４．０３ｋＪ·ｍｏｌ－１。

漆原钴法制备四羰基钴钠及羰基化反应

Sodium tetracarbonyl cobaltate was prepared by reaction of CO with CoCl2 inCH3OH, using Urushibara-Cobalt (U-Co) as activator and characterized by IR spectrometry-The optimum conditions were: Co(from U-Co)/CoCl2=0. 6; 30 ℃; 0. 1 MPa of CO. Theconvertion of CoCl2 in 3 h of reaction was 96%. The convertion of benzyl chloride to pheny-lacetic acid using the Na[Co(CO)4] as catalyst was about 90% at 50℃ and 0. 1 MPa of CO.

钴催化羰基化合成丙二酸二烷基酯

报道了原位合成的四羰基钴钠催化羰基化氯乙酸甲酯、氯乙酸乙酯和氯乙酸异丙酯合成相应丙二酸酯的反应,探讨了影响反应的几种因素。在优化的反应条件下,氯乙酸酯有较高转化率(95％左右),丙二酸二烷基酯有较高得率(90％以上)。实验显示这条绿色合成路线可望取代传统的氰化钠路线。探讨了氯乙酸烷基酯中烷基对反应活性的影响。

四羰基钴钠的制备研究

用红外光谱和碘量法定性、定量测定了四羰基钴钠均相络合催化剂的物化性能。讨论了用氯化钴和一氧化碳在常温常压下合成四羰基钴钠的反应中,温度、还原剂和溶剂的选择以及溶剂含水量对产率的影响。

四羰基钴/咪唑离子液体在羰基化合成丙二酸二甲酯反应中的催化性能

采用原位法合成了不同类型的四羰基钴/咪唑离子液体催化剂,并考察了其在氯乙酸甲酯羰基化反应中的催化性能.研究了咪唑环上不同支链对催化活性的影响.结果表明,1-丁基-3-甲基咪唑羰基钴离子液体[Bmim][Co(CO)4]不仅催化活性高,选择性好,而且对空气和水有较好的稳定性能.在pCO=2.0 MPa,85℃,反应3 h的条件下,[Bmim][Co(CO)4]催化剂循环使用4次,氯乙酸甲酯的平均转化率为94.3%,丙二酸二甲酯的平均选择性和平均产率分别为98.5%和92.9%.与传统的Na[Co(CO)4]催化剂相比,[Bmim][Co(CO)4]催化剂在保证高活性的条件下可以实现羰基钴催化剂的直接循环使用.

四羰基钴钠原釜高效催化羰基化环氧乙烷的研究

我们以保险粉及锌粉为还原剂、用Co(Ac)2.6H2O在一定条件下制备了Na[Co(CO)4]催化剂,此催化剂用于环氧乙烷羰基化合成了3-羟基丙酸甲酯,并考察了不同配体、温度、压力和时间对合成3-羟基丙酸甲酯的影响,得出最佳工艺条件为:3-羟基吡啶为配体,压力5 MPa,温度65℃,时间7 h。在此条件下3-羟基丙酸甲酯的选择性为95.6%,收率为86.3%。