【作者】 谭伟；

【导师】 石雷；

【作者基本信息】 辽宁师范大学 ， 物理化学， 2009， 硕士

【摘要】 N-苯基哌啶作为一种重要的有机原料和精细化工产品,在工业、农业和医药等领域中应用非常广泛。由苯胺和1,5-戊二醇气相合成N-苯基哌啶是N-苯基哌啶众多合成方法中最为经济的一种。与传统的合成方法相比较,该方法简便、成本低廉,并且避免了使用传统液相法中所需的大量有毒有机溶剂。本论文报道了一种简易可行的以γ-Al2O3作为催化剂的气相催化合成N-苯基哌啶的方法,通过常压气固相反应及NH3-TPD、BET和TG等表征方法对该催化剂进行了深入研究。主要得到了如下实验结果:1.以直接升温焙烧方法制备用于苯胺和1,5-戊二醇气相合成N-苯基哌啶的γ-Al2O3催化剂。该催化剂不仅制备方法简便、易于重复,而且活性和选择性较高。2.当活性Al2O3由室温升温至500℃并在此温度下焙烧4 h,在300℃的反应温度下N-苯基哌啶的收率可以达到92%。3.向反应体系通入氢气可以很好地清除催化剂表面的积碳。4.具有一定比表面积和孔容的γ-Al2O3催化剂活性高、选择性好。孔容过大或过小都不利于N-苯基哌啶的生成。5.通过量子化学计算和实验对苯胺和1,5-戊二醇合成N-苯基哌啶的反应机理进行了探讨,推出在γ-Al2O3催化剂的存在下,该反应是1,5-戊二醇先脱水生成四氢吡喃,然后四氢吡喃再和苯胺反应生成产物N-苯基哌啶。更多还原

【Abstract】 N-phenylpiperidine, which is an important organic raw material and fine chemical product, has many uses in the fields of industry, agriculture and medicine. There are many methods to produce N-phenylpiperidine. However, from the industrial, environmental and economical points of view, the synthesis from aniline and 1,5-pentanediol seems to be one of the most promising routes. Because it is easy from the reactants to N-phenylpiperidine and the raw materials are inexpensive, a low cost process on the industrial scale could be possible. Moreover, this method avoids using a large amount of organic solvent. Herein, we report a simple and practical catalyzed procedure for the synthesis of N-phenylpiperidine overγ-Al2O3 catalyst. The catalyst was investigated by means of some characterizations such as NH3-TPD, BET and TG . The main results are summarized as follows:1.γ-Al2O3 catalyst prepared by temperature-direct-calcination, exhibited very high activity and selectivity for the reaction of aniline and 1,5-pentanediol. It was prepared easily as well as obtained repeatly.2. When the active alumina was calcined at 500℃for 4 h with temperature-direct calcination method, the yield of N-phenylpiperidine could be up to 92% at the reaction temperature of 300℃.3. The carbon-deposition could be efficiently suppressed when hydrogen was added to the reaction system.4.γ-Al2O3 catalyst with appropriate specific surface area and total pore volume has high catalytic activity and selectivity. Too big or too small total pore volume couldn’t favor to obtain the high yield of N-phenylpiperidine.5. The mechanism of the reaction from aniline and 1,5-pentanediol to N-phenylpiperidine was investigated by quantum chemistry calculation. The dehydration of 1,5-pentanediol to tetrahydropyran is first presumed, then the synthesis of N-phenylpiperidine from tetrahydropyran and aniline takes place.更多还原