邻苯二胺与醛反应合成苯并咪唑衍生物的反应机理研究

Investigation on the Reaction Mechanism for the Synthesis of Benzimidazole Derivatives from Aldehydes and o-Phenylenediamine

以4-甲基苯甲醛与邻苯二胺反应合成2-(4-甲基苯基)苯并咪唑的反应为例,以HPLC方法跟踪反应进程,对关键中间体与产物的结构通过1H NMR,FT-IR及LC-MS等手段进行了表征.实验证明了在邻苯二胺和醛物质的量比为1∶1时同时生成单席夫碱和双席夫碱中间体的反应机理,并提出了该类反应的影响规律.

The synthesis of 2-（4-methyphenyl）benzimidazole from 4-methyl benzylaldehyde and o-phenylenediamine was performed.The reaction process was monitored by HPLC,and the structures of re-lated intermediates and products were identified by 1H NMR,FT-IR and LC-MS techniques.The experi-ments proved that mono-Schiff base and bis-Schiff base could both be synthesized at the same time when o-phenylenediamine and aldehydes were in a molar ratio of 1∶1,and the influences of the reaction were pro-posed.