Benzamides Substituted with Quinoline-Linked 1,2,4-Oxadiazole: Synthesis, Biological Activity and Toxicity to Zebrafish Embryo.

To develop new compounds with high activity, broad spectrum and low-toxicity, 17 benzamides substituted with quinoline-linked 1,2,4-oxadiazole were designed using the splicing principle of active substructures and were synthesized. The biological activities were evaluated against 10 fungi, indicating that some of the synthetic compounds showed excellent fungicidal activities. For example, at 50 mg/L, the inhibitory activity of (3-Cl-4-Cl substituted, 86.1%) against was superior to that of quinoxyfen (77.8%), and the inhibitory activity of (3-CF substituted, 77.8%) was comparable to that of quinoxyfen. The fungicidal activities of and to were better than that of quinoxyfen (14.19 mg/L), with EC of 6.67 mg/L and 5.17 mg/L, respectively. Furthermore, the acute toxicity of was 19.42 mg/L, classifying it as a low-toxic compound.