电喷雾萃取电离质谱监测Paal-Knorr反应的研究

Monitoring of Paal-Knorr Reaction Using Extractive Electrospray Ionization Tandem Mass Spectrometry

在线监测有机化学反应能够实时捕捉反应过程中反应物、中间体、产物的信号及其变化,从而加深对反应机理的认识。本实验采用电喷雾萃取电离质谱法(EESI-MS)实时在线监测甲醇为溶剂、乙酸为催化剂条件下,己二酮和苯胺的Paal-Knorr反应,在反应开始后的不同时间点,分别捕捉到了反应物、中间体、产物及其二聚体的准分子离子信号,并记录了它们在反应过程中随时间变化的趋势。该方法无需对反应体系中各物质进行预处理,缩短了延迟时间(响应时间少于1s),能够捕捉到短寿命中间体的信息,具有灵敏度高、特异性好、响应速度快等优点,可为化学反应的机理研究提供新思路。

Online monitoring of organic reactions can capture the signal and change of reaction reactants, intermediates and products, so as to deepen the understanding of the reaction mechanism. In this study, extractive electrospray ionization tandem mass spec- trometry （EESI-MS） were used to monitor Paal-Knorr about acetonylacetone and aniline under the condition of using methanol as solvent, acetic acid as a catalyst. At different time after the start of the reaction, the molecular ion peak of reactants, intermediates, product and dimer signal were captured, and the changes of them in the course of the reaction with time trends were recorded. This method does not require pretreatment of the analyte, which minimizes contamination of the instrument and greatly reduces the delay time （response time less than 1 s）, with the characteristics of high sensitivity, high specificity and fast response. It is able to capture short-lived intermediates, and thereby gives a true reflection of substance changes of chemical reactions. This work provides a new idea for the study of the mechanism of chemical reactions.