Synthesis, antifungal and insecticidal activity of novel [1,2,4]triazolo[4,3-a]pyridine derivatives containing a sulfide substructure

A series of [1,2,4]triazolo[4,3-a]pyridine derivatives bearing a sulfide substructure was designed, synthesized and characterized via H-1 center dot NMR, C-13 center dot NMR, IR and elemental analyses. Bioassay Results indicated some of the derivatives displayed good fungicidal activity on Rhizoctonia cerealis, moderated insecticidal activity against Plutella xylostella and good insecticidal activity on Helicoverpa armigera. The inhibitory effects of compounds 4g and 4u against Rhizotonia cerealis were 70.9% at 50 mu g mL(-1); the IC50 values of compounds 4d and 4s against Plutella xylostella were 43.87 and 50.75 mu g mL(-1), respectively. And the IC50 values of compounds 4d, 4q, and 4s on Helicoverpa armigera were 58.3, 77.14 and 65.31 mu g mL(-1), respectively, which were better than that of commercial chlorpyrifos (103.77 mu g mL(-1)).