文献类型：期刊文献

英文题名：Insight into the Claisen condensation of methyl acetate and dimethyl carbonate to dimethyl malonate

作者：Zheng, Sainan[1];Xu, Shiwei[1];Zhou, Jinghong[1];Shen, Rongchun[1];Ji, Yang[2];Shen, Ming[3];Li, Wei[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Shanghai Pujing Chem Ind Co Ltd, 1305 Huajing Rd, Shanghai 200231, Peoples R China;[3]East China Normal Univ, Shanghai Key Lab Magnet Resonance, 3663 Northern Zhongshan Rd, Shanghai 200062, Peoples R China

年份：2018

卷号：42

期号：9

起止页码：6689

外文期刊名：NEW JOURNAL OF CHEMISTRY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000431819200017)】；

基金：We gratefully acknowledge the support from the National Natural Science Foundation of China (21376076), and we thank Prof. Dr Bingwen Hu for help in NMR measurements.

语种：英文

摘要：A mechanistic study on the synthesis of dimethyl malonate (DMM) via condensation of methyl acetate (MA) and dimethyl carbonate (DMC), catalyzed by sodium methoxide, has been conducted using gas chromatography-mass spectrometry, liquid chromatography-electrospray ionization-mass spectrometry, X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy and density functional theory calculations. The results indicated that the Claisen condensation of MA and DMC in the presence of methoxide yielded (CH3OCO)(2)CHNa (DMNa) instead of DMM since DMM is easily deprotonated by the methoxide catalyst. Further protonation after the condensation by adding a proton-donor reagent is essential to obtain DMM. Based on the experimental results, a detailed reaction mechanism for the condensation of MA and DMC into DMM in the presence of methoxide has been proposed and disclosed by computational calculations. Besides, it has been proven that the base strength of the catalyst has a critical effect on the condensation reaction and the DMM yield.