Synthesis and Biological Activity of Novel Furan/Thiophene and Piperazine-Containing （Bis）1,2,4-triazole Mannich Bases

A series of novel furan/thiophene and piperazine-containing 1,2,4-triazole Mannich bases and bis（1,2,4-triazole） Mannich bases have been conveniently synthesized via Mannich reaction with triazole Schiff bases, various pipera- zinc derivatives, and formaldehyde as intermediates in good yields. Their structures were characterized by melting points, ~H NMR, 13C NMR, IR and elemental analysis. The preliminary bioassay showed that most compounds ex- hibited significant in vitro and in vivo fungicidal activity against several test plant fungi. Among 32 new compounds, the trifluoromethyl-containing compounds showed superior activity than the methyl-containing ones. Several com- pounds, such as FS, F9, F10, G5, HT, 118, 13 and 14, were comparable with some commercial fungicides against different fungi during the present study and could be further structurally optimized. Meanwhile, several compounds showed good herbicidal activity against Brassica campestris at 100 ~tg/mL and KARl inhibitory activity at 200 μg/mL. However, compounds exhibited poor insecticidal activity against oriental armyworm at 200 μg/mL in the preliminary studies. The research results will provide useful information for the design and discovery of new agro- chemicals with novel heterocyclic structures.