Design, Synthesis and Antifungal Evaluation of N‐Substituted‐1‐(3‐chloropyridin‐2‐yl)‐N‐(pyridin‐4‐yl)‐5‐(trifluoromethyl)‐1H‐pyrazole‐4‐carboxamide Derivatives

A series of 1‐(3‐chloropyridin‐2‐yl)‐5‐(trifluoromethyl)‐1 H ‐pyrazole‐4‐carboxamide derivatives which have di‐substituents on nitrogen were designed and synthesized. Bioassay results showed that all the synthetic compounds exhibited lower antifungal activities against Gibberella zeae , Cytospora mandshurica , and Fusarium oxysporum than T 3 (14.7, 21.1, and 32.7 μg/mL), but some of them exhibited better activities against Botrytis cinerea , Phytophthora infestans , and Sclerotinia sclerotiorum than T 3 (>200, >200, and >200 μg/mL); the EC 50 values of 7d and 7c against B. cinerea were 94.9 and 56.2 μg/mL, respectively. The EC 50 values of 7a , 7d , and 7c against S. sclerotiorum were 73.5, 78.7, and 68.5 μg/mL, respectively.