卤素交换氟化制备氟代苯甲醛研究

【作者】 徐珍；

【导师】 吕春绪；

【作者基本信息】 南京理工大学 ， 应用化学， 2006， 硕士

【摘要】 氟代苯甲醛是一类重要的有机化工原料及中间体，用途十分广泛。卤素交换氟化反应是合成含氟有机化合物的有效方法之一，卤素交换氟化反应是合成含氟有机化合物的有效方法之一，因此本论文研究了用卤素交换氟化法制备氟代苯甲醛，以对氯苯甲醛(PCAD)和无水KF为原料合成对氟苯甲醛(PFAD)的氟化反应。在溶剂选择、催化剂选择及配比催化机理、工艺优化、动力学以及副反应等方面进行了相关探讨。在投料比n(KF)：n(PCAD)=3，10ml硝基苯为溶剂，反应温度210℃，反应时间8h，n(KF)：n(PCAD)：n(1a)：n(1b)=3：1：0.1：0.05的最佳工艺条件下，产品对氟苯甲醛的收率可达80.9％，纯度99.5％以上，采用此方法还同时可以用于其它氟代苯甲醛化合物的合成。检测中发现了很多副产物，主要来自体系内中的水分，溶剂和反应物本身。但常规加热卤素交换氟化反应时间长、副反应程度大，因此在常规加热的基础上，初步探索了微波加热下卤素交换氟化反应制备对氟苯甲醛，发现微波加热可以加快反应速率，并能提高产率。动力学研究表明，常规加热条件下卤素交换氟化反应为一级反应，而在微波加热条件下明显不再是一级反应。这可以从宏观动力学上证明微波加热存在“非热效应”。更多还原

【Abstract】 Fluorobenzaldehyde is important raw material and intermediate with widely applictations.Halogen-exchange fluorination is the main and efficient method to synthesis fluorinated aromatics. Halogen-exchange fluorination is the main and efficient method to synthesis fluorinated aromatics. So Halogen-exchange fluorination was applied to synthesis fluorobenzaldehyde The fluorination of 4-chlorobenzaldehyde was studied in solvents using spray-dried KF as fluorinating agent. In addition, factors influencing the yield were discussed on solvents selecting, catalytic mechanism, process optimizing, dynamical equation and by reaction control. Under the optimum reaction conditions of n(KF):n(PCAD):n(la):n(lb)=3:l:0.1:0.05, reaction temperature 210℃, reaction time 8h and nitrobenzene as solvent, yield of 4-fluorobenzaldehyde was over 80.9% and the purity was more than 99.5%This method can also be used to synthesis other fluorobenzaldehyde. Many by-products were detected in the reaction mixture and considered to be formed deriving from water, solvent and the reaction themselves. Nevertheless, the traditional Halogen-exchange fluorination needs long time and inevitably companies with serious by-reactions. So under the traditional, microwave was applied to promote greatly the reaction rate and arise the yield. The kinetic research indicated that the traditional halogen-exchange fluorination was a first order reaction, but the microwave-promoted fluorination was obviously not a first order reaction yet, which was safe to take it for "non-heat" of microwave.更多还原