二苯乙烯类化合物的合成及其选择性硝硝化

摘要本文采用含有活泼氢的硝基芳烃作为原料与苯甲醛类化合物脱水缩合生成二苯乙烯类化合物。先选取苯甲醛与2,4,6-硝基-1,3-二甲苯为底物优化反应条件，在哌啶为催化剂，底物比为2.1:1，苯作为溶剂，回流12h的条件下，得到较高产量，为85%。之后，以哌啶为催化剂，讨论微波反应对该反应的促进作用。结果显示，微波能大大加快反应速率。接着，将苯甲醛换成其他芳基醛都得到了较好的结果。但同时发现，微波的参与无法改变该类反应发生的进度。最后，对采用该方法合成出的硝基二苯乙烯类化合物使用醋酸酐-硝酸体系进行选择性硝化。通常，苯乙烯和二苯乙烯采用乙酰硝酸酯硝化可以得到40~70%的β-硝基乙酸酯和其他副产物。但采用温和、易处理、易获得的醋酸酐-硝酸体系硝化硝基二苯乙烯类化合物得到的主产物为邻硝基衍生物，产率较高，可达70%以上。68589

毕业论文关键词二苯乙烯类化合物微波促进缩合选择性硝化醋酸酐-硝酸体系

毕业设计说明书（论文）外文摘要

Title The synthesis and selective nitration of stilbenes

Abstract

In this paper, stilbenes were synthesized from nitroaromatic compounds with active methyl group and benzaldehydes through Knoevenagel reaction. Benzaldehyde and 2,4,6-trinitro-1,3-xylene were explored as the model substrate to optimize the reaction conditions. Using the piperidine as a catalyst, benzene as solvent, keeping substrate molar ratio as 2.1:1 and refluxing for 12h, the highest yield was 85%. Then, with the piperidine as a catalyst, microwave assisted synthesis for stilbenes were also disscussed. The results showed that microwave irradiation could accelerate the reaction rate effectively. Furthermore, substituted benzaldehydes as substrates and corresponding stilbenes were obtained in an excellent isolated yield. However, there was no evidence showing that the microwave could modify the equilibrium of the reaction. Finally, acetic anhydride-nitric acid system was used to selectively nitrify the nitro-stilbene compounds. In general, nitration of styrenes and stilbenes with acetyl nitrate gave 40-70% yields of β-nitro acetates as well as other byproducts. However, nitrostilbenes can be converted to their ortho-nitrated derivatives with relatively high yield (up to 70%) using in situ acetyl nitrate as a mild, easily handled and commercially available nitrating reagent.

Keywords Stilbenes Microwave irradiation Condensation Selective nitration Acetic anhydride-nitric acid system

1 绪论 1

1.1 课题相关的研究进展 1

1.2 本课题的研究内容及其方法 6

2 实验试剂及仪器 8

2.1 实验试剂 8

2.2 实验仪器 9

3 二苯乙烯类化合物的合成 11

3.1 二苯乙烯类化合物的制备方法 11

3.2 反应条件对苯甲醛与2,4,6-硝基-1,3-二甲苯反应的影响 11

3.3 微波反应合成二苯乙烯类化合物 13

3.4 哌啶催化醛缩合反应的可能机理 16

3.5 二苯乙烯类化合物结构解析 17

3.6 本章小结 19 二苯乙烯类化合物的合成及其选择性硝硝化:http://www.youerw.com/huaxue/lunwen_77186.html