【作者】 阚显文；

【导师】 方宾；

【作者基本信息】 安徽师范大学 ， 分析化学， 2003， 硕士

【摘要】 苯甲醛类化合物是一类重要的药物中间体。目前通过无污染的方法来合成芳醛的新技术受到了高度的重视。超声波作用于化学反应具有加快反应速度、提高反应产率等优点已引起人们的极大注意。本文将超声波技术和间接电合成法相结合，将甲苯类化合物氧化成苯甲醛系列化合物。具体研究内容和结果如下： 探讨了氧化还原媒质Mn（Ⅱ）在铅电极上的电氧化机理，超声的参与使氧化电位和还原峰电位分别发生了一定程度的负移。从电流密度、氧化电位、H₂SO₄浓度和MnSO₄浓度等多个方面优化了超声电解的条件。新电解的氧化态媒质Mn（Ⅲ）氧化甲苯类物质得到了相应的药物中间体：苯甲醛、o-,m-,p-甲基苯甲醛。发现超声的加入，除p-甲基苯甲醛外，其它三种苯甲醛的产率均有提高，比较了超声对三种甲基苯甲醛产率的影响。且在超声合成中，可不必加入相转移催化剂，从根本上解决了媒质的再生问题。 建立了快速、简便的现场同时测定产物中苯甲醛和苯甲酸的电位滴定分析方法，相对标准偏差小于2％。 纳米粒子作为新一代的催化剂，在光、电方面表现出优良的催化性能。本论文合成了Ag、Ag₂O纳米粒子，探讨了它们对铅电极电解的催化作用，并用于Mn（Ⅱ）的电解过程，使其转化率均有所提高。更多还原

【Abstract】 Benzaldehydes are a type of important pharmaceutical intermediates. A new technology of electrosynthesis aromatic aldehyde with non-pollution has attracted increasing attention. Ultrasound acted on chemical reaction has enhanced the reaction rate and increased yield, which has aroused much attention. In this thesis, ultrasonic technique was combined with indirect electrosynthesis to oxidate toluenes to corresponding benzaldehydes. Investigations and results are as follows:Electro-oxidate mechanism of Mn（ II） as redox medium on Pb electrode was discussed, and oxidate potential and reduction peak potential were moved negatively under ultrasound. The conditions of electrolysis under ultrasound were optimized on aspects such as current efficiency, oxidate potential, concentration of MnSO₄ and H₂SO₄ Corresponding pharmaceutical intermediates: benzaldehyde, o-methyl--benzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde could be obtained by Mn（III） oxidating toluenes.The yields of three benzaldehydes were found to be increased expect p-methylbenzaldehyde when ultrasound was introduced in the reaction system. And ultrasound’s effect on yields of three methylbenzaldehydes was discussed. We also found that no phase-transfer catalyst was needed in the whole process, which made the recycle of the oxidation possible.A potentiometric titration method for determinating benzaldehyde and benzoic acid in electrosynthesis product simultaneously was established, and RSD was less than 2%.As a new generate catalyst, nanoparticles put up excellent catalyze characteristic on aspects of optics and electricity. Nano-Ag and nano-Ag20 have been successfully prepared as well as their catalyze function of electrolysising on Pb electrode were discussed. The yield of Mn（III） was increased by appling their catalyze function in electrolysis process.更多还原