中文摘要：

为了筛选出新的高活性化合物，以二氨基硫脲与有机羧酸为原料，回流反应生成中间体4-氨基-5-取代-1，2，4-三唑硫酮，再与羧酸在POCl3的催化下合成了3，6-双取代1，2，4-三唑并[3，4-b]-1，3，4-噻二唑新化合物。目标化合物通过IR、元素分析和。HNMR对其结构进行了表征。并初步测定了该化合物对5种植物病原菌（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）的杀菌活性，结果表明此类化合物对所测菌种具有良好的杀菌、抑菌作用。

英文摘要：

In order to screen out the novel highly-active compounds, the intermediate 4-amino-5-substituted-1,2 ,4- triazolethione was synthesized by using thiocarbohydrazide and carboxylic acids as raw materials, and then the new compounds of 3,6-disubstituted-1,2,4 -triazolo [ 3,4 -b ] -1,3,4-thiadiazole were synthesized by the intermediates 4 - amino-3-mercapto-5-substituted-1,2,4-triazole with carboxylic acids in the presence of phosphorus oxychloride as catalyst. The structures of target compounds were characterized by IR, elemental analysis and 1H NMR. Their preliminary biological activities to five vegetable pathogens （including Gibberlla nicotiancola, Pythium solani, Gibberlla saubinetii, Alternaria iycopersici and Fusarium oxysporium f. s. p. niveum ） were tested. The results show that most of them exhibit good fungicidal activities.