Synthesis and biological activities of novel triazole piperzazine derivatives

Twenty novel triazole piperzazine derivatives 7a - 7t were synthesized using 1,2,4-triazol, 2-chloro-1-(2,4-difluorophenyl) ethanone and piperzazine compounds as the starting materials, through the combination of active substructures. All target compounds were characterized by ¹H NMR, ¹³C NMR and HRMS. The fungicidal activities and insecticide activities of compounds were evaluated by the hyphal growth rate method and the drop method. The results showed that most of those compounds exhibited high inhibitory effects against Rhizoctonia solani, Fusarium graminearum and Magnaporthe oryzae. Compounds 7n , 7r and 7s exhibited good fungicidal activities with the inhibition rate of 60.19%, 62.27% and 50.00% against F. graminearum at the concentration of 200 μmol/L, resepectively. They were equal to triadimenol. And the EC₅₀ value of compound 7r was 49.49 μmol/L against R. solani. Moreover, The results indicated that compound 7o showed 40.00% mortality rate against Spodoptera litura larva at 100 mg/L, which was slightly lower than that of the commercial insecticide cyhalothrin (46.67%). The compounds with good fungicidal activities and insecticidal activities were synthesized in this work, which provided a reference for the activity study for novel triazole piperzazine derivatives.