Synthesis, Structure and Biological Activity of Novel 1,2,4-Triazole Mannich Bases Containing a Substituted Benzylpiperazine Moiety

A series of novel Mannich bases with trifluoromethyl-1,2,4-triazole and substituted benzylpiperazine moieties were synthesized. Their structures were confirmed by IR, (1)H NMR and elemental analysis. The single crystal structure of compound 4r was also determined. The preliminary bioassays showed that most of the lead compounds had low herbicidal activity against Brassica campestris, Echinochloa crusgalli, and KARI enzyme. However, most of them exhibited significant fungicidal activity at the dosage of 50 mu g/mL toward five test fungi. Among the 18 novel compounds, several showed superiority over the commercial fungicide Triadimefon against Cercospora arachidicola and Fusarium oxysporum f. sp. cucumerinum during this study. Meanwhile, some compounds displayed plant growth regulatory activity at the dosage of 10 mu g/mL.