Synthesis and antifungal activities of pyrazole derivatives containing oxime esters

In order to discover lead compound with high antifungal activities, 17 novel pyrazole derivatives containing oxime esters were designed and synthesized based on our previous studies. Their structures were characterized by ¹H NMR, ¹³C NMR and HRMS, and the crystal structure of compound 7q was confirmed by X-ray diffraction. The bioassay results showed that target compounds displayed antifungal activities against Valsa mali, Sclerotinia sclerotiorum, Botrytis cinerea and Gaeumannomyces graminis. Especially, compound 7q exhibited satisfied activity against B. cinerea with the EC₅₀ value of 7.04 μg/mL, which was better than that of the lead compound ( L1 ) and trifloxystrobin.