【作者】 王雪；

【导师】 刘晓智；

【作者基本信息】 辽宁大学 ， 有机化学， 2019， 硕士

【摘要】 脲类化合物因其广泛的用途在许多领域有着重要的应用尤其在农药、医药领域,由于其是合成许多药物的重要中间体和原料被普遍应用于医药研究,并且因具有杀菌、除草等功效被普遍应用于农药生产行业。因此对脲类化合物的合成方法进行更深入的探索意义重大。本论文是在Se/CO体系的基础之上进行了更深一步的探究。在常压条件下,以硝基苯类化合物作为底物,与水、CO进行反应,在Se的催化下一步合成出二苯脲类化合物。相比高压反应,从反应本身来说,因其较高的选择性而使副反应明显减少;从绿色化学的角度来说,常压反应相对而言对反应设备的要求没有那么高,因此不仅使操作过程的危险系数明显下降,而且有效提高了生产率。并且副产物的减少意味着简化了后处理的步骤,降低了成本,节约了能源。实验部分主要是以硝基苯为例,依据实验数据对溶剂、助催化剂进行了选择,还探究了溶剂、助催化剂、硒粉、底物、水等的适宜用量,以及适宜的温度和时长。并得到最优投料量及反应条件:硝基苯5 mmol,Se 0.2 mmol,乙酸钠3 mmol,水2 mL,DMF 20 mL,温度95℃,时间3 h,CO采用持续鼓泡的方式通入。在上述的反应条件下进行实验得到二苯脲的产率在97%左右。将上述投料比应用于带有其他取代基的硝基苯类化合物进行反应得到一系列的二苯脲。后续通过重结晶、柱层析等进行提纯。产物纯品再经过熔点仪进行熔点测定,最后通过~1H NMR和IR进一步确定产物结构。本论文旨在以实验为基础优化硒催化硝基苯类化合物在常压条件下羰基化合成二苯脲的反应,并以实验结果为依据提出了一种反应机理来详细解释二苯脲的生成过程以及副产物苯胺在反应过程中的重要作用。更多还原

【Abstract】 Urea compounds have important applications in many fields,especially in the fields of pesticides and medicines.It is widely used in medical research because it is an important intermediate and raw material for the synthesis of many drugs.In the pesticide industry,it is widely used in the production of pesticides due to its efficacy in sterilization and weeding.Therefore,it is necessary to further explore the synthesis methods of urea compounds.This paper is further exploration based on the Se/CO system.The nitrobenzene compounds are used as substrates to react with water and CO under the normal pressure conditions.Se was used as a phase transfer catalyst in the reaction to synthesize diphenylurea compound in one step.Different from the high pressure reaction,the side reaction is obviously reduced due to its higher selectivity from the reaction itself;From the perspective of green chemistry,the atmospheric pressure reaction is relatively less demanding on the reaction equipment,and it also reduces the risk of operation and increases productivity.The increased selectivity of the reaction can effectively reduce the type of by-products,which means that the post-treatment step is simplified.Thereby,it is effectively reducing the cost of the synthesis and saving energy.This paper mainly uses nitrobenzene as a substrate.The solvent and cocatalyst have been selected through a large number of experiments.The optimum amount of solvent,cocatalyst,selenium powder,substrate,water,etc.,as well as the appropriate temperature and duration are also explored.And determined the best conditions:nitrobenzene 5 mmol,Se 0.2 mmol,sodium acetate 3 mmol,water 2 mL,DMF 20 mL,temperature 95℃,time 3 h,CO continuous bubbling.The experiment was carried out under the above reaction conditions to obtain a yield of diphenylurea of about 97%.The above feed ratio is applied to a nitrobenzene compound with other substituents to obtain a series of diphenylureas.The product is purified by column chromatography,recrystallization,etc.The melting point of the pure product was determined by melting point instrument.Finally the structure was determined by ~1H NMR and IR.The aim of this thesis is to optimize the reaction of selenium-catalyzed carbonylation of nitrobenzene compounds to synthesize diphenylurea under normal pressure conditions.Based on the experimental results,a reaction mechanism was proposed to explain the formation of diphenylurea and the important role of by-product aniline in the reaction process.更多还原