In search of new low toxicity and potent pesticide lead compounds, a series of novel pyrazole oxime ether derivatives containing a pyridyl ring were synthesized by the condensation of N-pyridyl pyrazole oximes with 2-chloro-5-chloromethyl pyridine. Their structures were determined by ¹H NMR, ¹³C NMR spectra and elemental analysis. Preliminary bioassay showed that some of the target compounds displayed fungicidal, insecticidal, and plant growth regulatory activities to some extent. For example, compound 5c exhibited 61.4% inhibition rate against Alternaria solani at the concentration of 50 μg/mL, compound 5j showed 60.2% inhibition rate against Cercospora arachidicola at the concentration of 50 μg/mL, the mortality rate of compound 5i was 50.3% against Aphis craccivora at the concentration of 500 μg/mL, and compound 5f displayed 71.0% promotion effect on the radicle growth of cucumber cotyledons at the concentration of 10 μg/mL.

Key words: pyridine, pyrazole oxime ether, synthesis, biological activity