烷基三唑硫酮席夫碱的合成和生物活性研究

为进一步研究三唑席夫碱化合物的合成与性质,以自制的5-烷基-4-氨基-1,2,4-三唑-3-硫酮与对甲氧基苯乙酮和取代芳醛为原料,在冰醋酸催化下,回流反应0.5 h,合成了1,2,4-三唑硫酮席夫碱化合物,其结构通过元素分析、红外光谱(IR)和核磁共振(1H NMR)进行表征。分析结果表明:在IR图谱中,目标产物在波数1 587—1 603 cm-l处出现席夫碱亚胺结构CHN的特征吸收峰;在1H NMR中,席夫碱亚胺结构CHN的质子化学位移δ在10.5附近出现,NC—CH3结构中H的化学位移在2.4左右。研究了化合物对烟草赤星病、马铃薯干腐病、小麦赤霉病、番茄早疫病、西瓜枯萎病5种植物病原菌的生物活性,得到毒力回归方程及相关系数,计算EC50和EC95值,结果表明它们具有较好的抑菌活性。含有吸电子取代基的席夫碱杀菌效果比给电子取代基的好。

Synthesis and biological activities of 5-alkyl-4-amino-1,2,4-triazole-3-thione Schiff bases

In order to further study the synthesis and properties of Schiff bases of triazole,five triazolethione Schiff bases were synthesized by using 5-alkyl-4-amino-1,2,4-triazole-3-thione with p-methoxyacetophenone and substituted aldehydes as raw materials in the presence of glacial acetic acid as catalyst under refluxing reaction of 0.5 h.The structures of the compounds were characterized by elemental analysis,infrared spectroscopy(IR),and nuclear magnetic resonance(1H NMR).The results show that all the compounds have the CHN characteristic absorption band at 1 587-1 603 cm-l in IR,and the proton chemical shift of CHN is around δ=10.5 and the H shift of NC—CH3 is around δ=2.4 in 1H NMR.Their biological activities to the five vegetable pathogens of Gibberella nicotiancola,Pythium solani,Gibberella saubinetii,Alternaria iycopersici and Fusarium oxysporium f.s.p.niveum were tested.The toxic regression equation and correlation coefficient were obtained.The EC50 and EC95 were calculated.The results show that they exhibit good fungicidal activities.The Schiff bases containing an electron withdrawing substituent have better fungicidal activities than those containing an electron donating substituent.