Green Synthesis, In Silico Molecular Docking, and Evaluation of Pyrazole Derivatives for Their Antifungal and Antinemic Activity

A series of 25 pyrazole derivatives was synthesized via ultrasonication‐assisted cyclization of chalcones with phenylhydrazine and characterized using 1 H NMR, 1 3 C NMR, and LC‐HRMS. Biological evaluation revealed that P‐25 [5‐(4‐fluorophenyl)‐1,3‐diphenyl‐1 H ‐pyrazole] exhibited the highest antifungal activity against Rhizoctonia solani (ED 50 = 5.56 µg mL − 1 ), approaching the efficacy of positive control hexaconazole 5% SC (ED 50 = 3.67 µg mL − 1 ). While P‐6 [5‐(3‐nitrophenyl)‐1,3‐diphenyl‐1 H ‐pyrazole] was most effective against Fusarium oxysporum (ED 50 = 301.5 µg mL − 1 ). In nematicidal assays, P‐21 [3‐(4‐ethoxyphenyl)‐5‐(4‐nitrophenyl)‐1‐phenyl‐1 H ‐pyrazole] showed the greatest activity against Meloidogyne incognita (LC 50 = 31.25 µg mL − 1 , 24 h) although less potent than fluopyram 34.48% SC (Velum Prime) (LC 50 = 3.46 µg mL − 1 ). Molecular docking studies targeting succinate dehydrogenase (SDH) supported the experimental results, with P‐6 , P‐25 , and P‐21 exhibiting the strongest binding affinities against SDH of F. oxysporum (−8.3 kcal mol − 1 ), R. solani (−8.3 kcal mol − 1 ), and M. incognita (−7.7 kcal mol − 1 ), respectively.