咪唑并[1,5-a]吡啶的合成工艺研究

Research on the Synthesis of Imidazo[1,5-a]Pyridine

目的:基于氧化碳氢键官能团化策略,重新构建咪唑并[1,5-a]吡啶的合成方法。方法:以2-苄基吡啶和苄胺为反应原料,采用单因素试验法,考察了催化剂、添加剂、溶剂、反应温度、反应时间和投料比对反应的影响,寻找最佳反应条件,并对所得目标产物分别用核磁共振氢谱(1 H-NMR)、核磁共振碳谱(13 C-NMR)进行结构表征。结果:以溴化亚铜二甲硫醚作为催化剂,甲苯作为溶剂,特戊酸作为添加剂,温度为110℃条件下,苄基吡啶和苄胺可以反生串联环化反应,以较高的收率得到目标产物咪唑并[1,5-a]吡啶。结论:开发了一种铜催化的咪唑并[1,5-a]吡啶合成方法,该合成方法采用价廉易得的苄胺和苄基吡啶为起始原料,避免了底物的预先官能团化,减少了操作步骤,具有较好的实用性。

Objective：To develop a new synthetic method for constructing imidazole[1,5-a]pyridines based on the oxidative hydrocarbon bond functionalization strategy.Methods：2-Benzylpyridine and benzyl amine were chosen as substrates.To find the best reaction conditions,the catalysts,additives,solvents,reaction temperature,reaction time and the reaction of charge ratio wer examined by using the single factor experiment method.The chemical structure of the target products was characterized by 1 H and 1 3 C NMR spectroscopy.Results：With cuprous bromide dimethyl sulfide as catalyst,toluene as solvent,pivalic acid as additive,tandem cyclization of 2-benzylpyridine with benzyl amines to obtain imidazo[1,5-a]pyridines at 110 ℃ with higher yield.Conclusion：A copper catalyzed reaction to synthesize imidazole[1,5-a]pyridines was developed.The synthetic method,which utilize cheap benzylamine and 2-benzylpyridine as starting materials to avoid pre-functionalization of the substrates,can reduce the operation steps and has good practicability.