由α-氰基肉桂酸乙酯/N-溴代苯甲酰胺合成2-噁唑啉衍生物  

Synthesis of 2-Oxazoline Derivatives from Ethyl α-Cyanocinnamate Derivatives and N-Bromobenzamide

作　　者：惠文萍 刘德娥 侯丹[1] 陈战国[1] 

机构地区：[1]陕西师范大学化学化工学院,陕西省大分子科学实验室,西安710119

出　　处：《应用化学》2017年第7期757-767,共11页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(20572066);陕西省自然科学基金(2009JM2011);陕西师范大学研究生创新基金(2008CXB009)资助~~

摘　　要：作为重要的杂环化合物,合成新的2-噁唑啉衍生物以及发展其新的合成方法具有重要意义,为此以α-氰基肉桂酸乙酯衍生物为底物,以N-溴苯甲酰胺为反应试剂,在无水碳酸钠(相对于底物3为110%摩尔分数)促进下,在丙酮溶剂中,室温下,建立了合成相应2-噁唑啉衍生物的新方法,共合成了11个新化合物,其结构由核磁共振波谱仪(~1H NMR,^(13)C NMR)和高分辨质谱(HRMS)确认。结果显示,各种α-氰基肉桂酸乙酯衍生物(3a^3k)可被顺利的转化成相应的2-噁唑啉衍生物(5a^5k)。在室温下,丙酮作溶剂,以Na_2CO_3为促进剂时,相应产物的最高收率可达90%。不仅α-氰基肉桂酸乙酯衍生物(3)可被用作该反应的底物,而且α-乙氧甲酰基肉桂酸乙酯(6)也适用于该反应。实验结果还证明,除了N-溴代苯甲酰胺外,N-溴代对硝基苯甲酰胺(8)及N-溴代乙酰胺(9)也适用该反应,证明该方法具有广泛的适应性。根据实验结果,提出了可能的反应机理,该机理支持了形成2-噁唑啉衍生物的区域选择性。2-0xazoline derivative belongs to an important class of heterocyclic compounds, new synthetic method and new 2-oxazoline derivatives are eagerly desired. In order to develop a new protocol for the synthesis of deferent structural 2-oxazoline derivatives, a method from ethyl α-cyanocinnamate derivatives and N-bromobenzamide has been explored. The structures of all eleven synthesized products were confirmed by proton nuclear magnetic resonance spectroscopy （ 1H NMR）, and mass spectrometry （MS）. The results show that a series of ethyl a-cyanocinnamate derivatives （3a -3k） can be smoothly converted into corresponding 2-oxazoline derivatives（5a-5k）. When Na2CO3 was used as the promoter in acetone at room temperature, the corresponding products were obtained in high yield （ up to 90% ）. Not only can ethyl α-cyanocinnamate derivatives be used as substrate, but also ethyl α-carbethoxy-eyanocinnamate （6） can be employed as the substrate, too. Experiment results indicate that N-bromo-p-nitrobenzamide （8） and N-bromoacetamide （9） can tolerate this reaction except N-bromobenzamide （4）. Above results indicate that the easy and efficient protocol has application in a large scope of electron-deficient olefins and N-bromoamide. A possible mechanism was proposed which can explain well the full regiospeeificity of the reaction.

关 键 词：α-氰基肉桂酸乙酯 N-溴本甲酰胺 噁唑啉衍生物 

分 类 号：O626.3[理学—有机化学]