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论文编号:HG200 论文字数:12288,页数:26
摘要：三氟乙酰乙酸乙酯是合成医药和农药的重要中间体。本文通过三氟乙酸乙酯和乙酸乙酯进行Claisen缩合反应制备三氟乙酰乙酸乙酯，比较了以氢化钠、醇钠、钠为催化剂对收率的影响。结果表明以现制的乙醇钠为催化剂，在不加溶剂条件下，三氟乙酸乙酯和乙酸乙酯进行Claisen缩合，然后用无水甲酸进行中和，再用乙酰氯进行乙酰化，最后减压蒸馏得到三氟乙酰乙酸乙酯的收率最高，可达到75％。对实验中最重要的影响因素反应温度进行了系统的研究，实验结果表明最佳反应温度在65-70℃之间。
关键词：三氟乙酰乙酸乙酯；乙醇钠；Claisen缩合
Abstract: Ethyl-trifluoroacetoacetate is used as an important intermediate in the synthesis of pharmaceutical or plant protection industry. Ethyl-trifluoroacetoacetate is prepared by Claisen condensation of Ethyl-trifluoroacetate and ethyl acetate. The catalyst of the reaction is sodium hydride, sodium or sodium ethoxide. By comparing of the effect of these catalysts to the yield, the result indicates that preparing by the following way, the yield can reach the maximum 75%: In the first step, Ethyl-trifluoroacetate is condensed with ethyl acetate in the presence of sodium ethoxide. In the second step, the condensation product is neutralized with a protonic acid, such as formic acid. In the third step, the neutralization slurry is acetylized with acetyl chloride. At last, the Ethyl-trifluoroacetoacetate obtained is separated by distillation. The most important factor of this process is the temperature of reaction. The results of the experiment show that the best temperature of reaction is between 65 to 70℃. Keywords: Ethyltrifluoroacetoacetate; Sodium ethoxide; Claisen condensation
目 录
中文摘要………………………………………………………………………………………Ⅰ
英文摘要………………………………………………………………………………………Ⅱ
目录……………………………………………………………………………………………Ⅲ
1.绪论……………………………………………………………………………………………1
1.1引言………………………………………………………………………………………1
1.2研究现状…………………………………………………………………………………1
1.2.1以氢化钠作催化剂…………………………………………………………………1
1.2.2以金属钠作催化剂…………………………………………………………………2
1.2.3以乙醇钠为催化剂…………………………………………………………………2
1.3实验设计…………………………………………………………………………………2
2.实验……………………………………………………………………………………………4
2.1试剂、样品、仪器………………………………………………………………………4
2.1.1试剂…………………………………………………………………………………4
2.1.2原料及产物的物理性质……………………………………………………………5
2.1.3仪器…………………………………………………………………………………5
2.2催化剂的比较 …………………………………………………………………………6
2.2.1以金属钠作催化剂…………………………………………………………………6
2.2.2以氢化钠作催化剂…………………………………………………………………7
2.2.3以乙醇钠作催化剂…………………………………………………………………7
2.2.4后处理……………………………………………………………………………8
2.3以乙醇钠为催化剂无溶剂条件下最佳反应温度的选择………………………………9
3.实验结果与讨论……………………………………………………………………………11
3.1标准品的气相分析谱图…………………………………………………………………11
3.2催化剂的比较实验结果…………………………………………………………………12
3.2.1以钠作催化剂的实验结果………………………………………………………13
3.2.2以氢化钠作催化剂的实验结果…………………………………………………14
3.2.3以乙醇钠作催化剂的实验结果…………………………………………………14
3.2.4催化剂比较实验结果分析………………………………………………………15
3.3以乙醇钠为催化剂无溶剂条件下最佳反应温度的选择………………………………16
3.4实验讨论………………………………………………………………………………17
3.5本章小结………………………………………………………………………………18
4.总结与展望…………………………………………………………………………………20
致谢……………………………………………………………………………………………21
参考文献………………………………………………………………………………………22
