微波辅助合成菲并咪唑衍生物及微波非热效应

Microwave-assisted Synthesis of Imidazole[4,5f][1,10]phenanthroline Derivatives and Microwave Nonthermal Effect

以1,10-邻菲啰啉5,6-二酮及苯甲醛(或取代苯甲醛)为原料,在微波辐射条件下制备了一系列菲并咪唑类衍生物,考察了温度、时间以及投料比对微波辅助合成菲并咪唑类衍生物的影响,并进一步探讨了微波非热效应的影响.设计正交实验优化了反应条件;使用SiC管作为反应容器屏蔽微波对反应的影响;通过元素分析、核磁共振波谱、质谱及红外光谱等对化合物进行了表征.结果表明,微波辅助反应的最佳反应条件为:1,10-邻菲啰啉-5,6-二酮与苯甲醛(或取代苯甲醛)的投料比为1∶1.5,反应温度为100℃,反应时间为20 min;并且发现SiC管中反应的产率明显低于石英管反应容器.与传统制备方法相比,微波辅助合成方法可在更短时间内快速方便地制得菲并咪唑类衍生物;反应温度、反应时间以及投料比对微波辅助合成反应有明显影响;微波非热效应有助于提高反应产率.

A series of imidazole[4,5f][1,10]phenanthroline and its derivatives were synthesized using 1,10-phenanthroline and various benzaldehydes and substitute benzaldehydes as raw materials in Pyrex reactor through application of microwave-assisted heating technology with the yield of 52%-89%, and the target compounds were characterized and in agreement with that of literature. The orthogonal test methods were used to optimize the synthesis conditions of PIP and the results indicated that the yield of PIP will reach to 89% under the irradiation of microwave for 20 min at 100℃ with a reactant ratio of n（phenanthroline）： n（benzaldehydes）=1.0： 1.5. Compared with the conventional synthesis method, microwave-assisted synthesis offers a simple feasible method to synthesize imidazole[4,5f][1,10]phenanthroline and its derivatives with high yield in a short time. Further studies on the synthesis of p-BrPIP in SiC vial, which adsorb the microwave and transfer it to heat instantly, showed a reducing yield but improving stability of the reaction compare to that in prexy vial attributed to the nonthermal effect of microwave.