Design, synthesis and antifungal activity of novel fenfuram analogues containing a diarylamine moiety

Abstract:

Carboxylic amides are one of the most important classes of agricultural fungicides. To discover new carboxylic amide analogues with high activity against plant pathogenic fungi, twenty novel fenfuram analogues containing a diarylamine moiety were designed, synthesized and characterized by 1H NMR. Their antifungal activities in vitro were evaluated against four phytopathogenic fungi（Rhizoctonia solani, Sclerotinia sclerotiorum，Pythium aphanidermatum and Fusarium oxysporum）by mycelium growth inhibition method. Most compounds showed significant antifungal effect on R. solani and S. sclerotiorum, however, slightly weak antifungal effect on B. cinerea and F. oxysporum. Compound 1i exhibited the most potent antifungal effect on S. sclerotiorum with EC50 value of 1.9229 mg/L, superior to commercial fungicides boscalid (EC50 = 2.6736 mg/L) and lead fungicide fenfuram (EC50 = 9.9667 mg/L). The present work demonstrated that fenfuram analogues containing a diarylamine moiety could be used as a lead structure for further developing novel fungicides.