无溶剂条件下喹喔啉衍生物碳氮双键还原反应

Reduction of carbon-nitrogen double bonds of quinoxaline derivatives under solvent-free conditions

研究一种在室温、无溶剂条件下以硼氢化钠为还原剂还原喹喔啉衍生物碳氮双键的方法。考察还原剂、添加剂、溶剂、反应时间和温度对反应的影响。给出反应的优化条件,即以硼氢化钠(2当量)为还原剂,硅胶为添加剂,它们的质量比为1∶3时,在室温碾磨0.1h,产物收率可达90%。目标产物经过了1 HNMR、13CNHM和HRMS确证。该合成方法具有条件温和、操作简单、反应时间短、产率高及对环境友好等优点,是一种高效的亚胺还原方法。

A method for reduction of carbon nitrogen double bonds of quinoxaline derivatives was studied using sodium borohydride as reducing agent under solvent-free conditions at the room temperature. The effects of reducing agent, additive, solvent, reaction time and temperature on reaction were investigated. The results showed that the optimum reaction conditions were 1 ： 3 mass ratio of borohydride （2.0 eq ） as reducing agent and silica gel as additive; 90 % yield was obtained under milling at the room temperature for 0. 1 hour. The products were identified by 1 HNMR 13 CNMR and HRMS. This synthetic method boasts mild conditions, simple operation, short reaction time, high yield and eco-friendliness, and proves to be a highly efficient method for reduction of imines.