A series of novel quinazolin-4(3H)-one derivatives (6a–6y) containing a 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole moiety were designed and synthesized, and their structures were fully characterized by ¹H NMR, ¹³C NMR, HRMS and IR spectra. Among them, the structure of compound 6u was unambiguously confirmed via single crystal X-ray diffraction analysis. The obtained bioassay results showed that compounds 6h, 6k, 6l and 6y had the EC₅₀ (half-maximal effective concentration) values of 34.8, 28.2, 41.5 and 42.5 μg/mL against the phytopathogenic bacterium Xanthomonas oryzae pv. oryzae (Xoo), respectively, which were significantly better than commercial bactericide Bismerthiazol (EC₅₀ = 95.8 μg/mL). Additionally, compounds 6a and 6b exhibited the strong inhibition activity against the pathogen Xanthomonas axonopodis pv. citri (Xac).

设计并合成了一系列新的包含1,2,4-三唑并[3,4- b ] [1,3,4]噻二唑部分的喹唑啉-4（3 H）-一衍生物（6a - 6y），并它们的结构通过¹ H NMR，¹³ C NMR，HRMS和IR光谱充分表征。其中，通过单晶X射线衍射分析明确地确认了化合物6u的结构。获得的生物测定结果表明化合物6h，6k，6l和6y具有EC ₅₀致病性细菌米生黄单胞菌pv的（最大最大有效浓度）值为34.8、28.2、41.5和42.5μg/ mL 。米糠（Xoo）分别显着优于商业杀菌剂Bismerthiazol（EC ₅₀  = 95.8μg / mL）。另外，化合物6a和6b显示出对病原体黄单胞菌xv的强烈抑制活性。柠檬（Xac）。