含嘧啶环的1,3,4-噁二唑Mannich碱的合成及生物活性

以芳香酸为原料, 通过酯化、 肼解及环化反应制得中间体5-芳基取代-1,3,4-噁二唑-2-硫酮(C1~C3), 然后中间体与甲醛和取代氨基嘧啶(D1~D5)发生Mannich反应得到一系列新型含有嘧啶环的1,3,4-噁二唑类衍生物(E1~E15). 所得目标化合物的结构经元素分析、 IR及 ¹H NMR确认. 初步的生物活性测定结果表明, 大部分目标化合物对植物病原菌有很好的抑制作用, 其中化合物E3和E8的抑菌效果优于对照药三唑酮.

Synthesis and Biological Activity of 1,3,4-Oxadiazole Mannich Bases Containing Pyrimidine Rings†

1,3,4-Oxadiazole derivatives were reported to possess a broad spectrum of biological activities, such as antifungal, antibacterial, antiviral and antitubercular. Mannich bases had also been reported as potential biological agents, they were applicated in the fields of synthetic study and medicinal chemistry. In recent years, Mannich bases containing 1,3,4-oxadiazole ring had attracted a lot of attention and many Mannich bases of 1,3,4-oxadiazole bearing heterocycle scaffold were reported to have special bioactivity. Nevertheless, literature revealed that there were no reports of a molecular scaffold that Mannich base of 1,3,4-oxadiazole bearing pyrimidine. Prompted by these observations, a series of 1,3,4-oxadiazole derivatives containing pyrimidine(E1—E15) was synthesized from 5-aryl-1,3,4-oxadiazole-2-thione(C1—C3), formaldehyde and substituted aminopyrimidine(D1—D5) by Mannich reaction. 5-Aryl-1,3,4-oxadiazole-2-thione derivatives(C1—C3) were prepared from aromatic acids as the starting material via esterification, hydrazinolysis and cyclization. The structures of all title compounds were confirmed by elemental analysis, IR, ¹H NMR techniques. Furthermore, their biological activities to four vegetable pathogens containing Gibberll nicotiancola, Gibberlla saubinetii, Fusarium oxysporium f. sp. niveum, Pythium solani had been tested. The preliminary results indicated that most of the compounds exhibit relatively good fungicidal activities, especially compounds E3 and E8 showed better biological activity than triazolone.