Synthesis and biological activity of novel dimethylpyrazole and piperazine-containing (bis)1,2,4-triazole derivatives

A series of novel dimethylpyrazole and piperazine-containing (bis)1,2,4-triazole derivatives have been conveniently synthesized via Mannich reaction in good yields. Their structures were identified by IR, H-1 NMR, C-13 NMR, and elemental analysis. The preliminary bioassays showed that among 14 new compounds, the trifluoromethyl-containing compounds exhibited superior activity than the methyl-containing ones; some of the compounds displayed significant in vitro and in vivo fungicidal activity against several plant fungi and were comparable with the control Triadimefon; several compounds exhibited certain herbicidal activity against Brassica campestris; several compounds possessed favorable KARI inhibitory activity, especially 8D could be a promising KARI inhibitor for further study. The research results will provide useful information for the design and discovery of new agrochemicals with novel heterocyclic Mannich base structures containing piperazine moiety.