微波法合成1,3-二芳基吡嗪[1,2-a]苯并咪唑衍生物

Microwave Supported Synthesis of 1,3-Diarylpyrazino[1,2-a]Benzimidazole Derivatives

以苯并咪唑为原料,通过4步反应合成目标产物1,3-二芳基吡嗪[1,2-a]苯并咪唑衍生物,在该反应中,前两步反应通过简单的原料和常规方法合成其中间产物,第三步脱羰基合环以微波辐射为反应条件。中间产物2-芳基苯并咪唑类化合物(1a,1b),1-(2-芳基-2-氧乙基)-2-芳基苯并咪唑衍生物(2a,2b)和目标产物1,3-二芳基吡嗪[1,2-a]苯并咪唑衍生物通过核磁、质谱、红外、元素分析等方法进行结构鉴定并确认。该方法合成简单可行,微波辐射下的有机合成,反应更加快速高效,产率也相应的提高,减少了剧烈反应带来的潜在危害性。由于反应时间的缩短,也减少了副产物的产生,该实验所用原料简单易得,工艺可控,为此类化合物的制备提供了一条更佳途径,也为工业化生产提供了一定的基础。

Synthesis of the 1,3-diarylpyrazino [1,2-a] benzimidazole derivatives by microwave.2-aryloylbenzimidazole derivative was reacted with 2-bromoacetophenonesin acetone to give 1-（2-aryl-2-oxoethyl）-2-aryloylbenzimidazoles,in the reaction,the first two steps for the synthesis of the intermediate product by simple raw materials and the conventional method,the third step decarbonylation of loop to microwave radiation reaction conditions.The intermediate 2-arylbenzimidazoles（1a,1b）,1-（2-aryl-2-ethyl）-2-arylbenzimidazole derivatives （2a,2b） and target product 1,3-diarylpyrazino [1,2-a] benzimidazole derivatives were confirmed by NMR,MS,IR,EA.The synthetic route was simple,feasible and convenient than traditional ones.Under microwave irradiation,organic synthesis not only reacts more quickly and efficiently,but also increases corresponding,,and reduces the potential harm caused by the violent reaction.Because of the shorter reaction time,harmful production is reduced.The used raw materials are easy to obtain,the process is controlable,.The preparation provides a better way for such compounds,and also provides a foundation for industrialized production.