Abstract: Based on the structure of the fungicide fenfuram, twenty novel 2-methyl-3-furancarboxamide derivatives were designed, synthesized characterized by 1H NMR. Their in vitro antifungal activities were evaluated against five normal phytopathogenic fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Phytophthora infestans, Pythium aphanidermatum, Physalospora piricola by mycelial growth inhibition method. Compounds 1e, 1f, 2a, 2b and 2f exhibited stronger antifungal effect on R. solani with inhibition of 88.6 %, 74.5 %, 78.5 %, 78.7 % and 73.1 %, respectively, superior to commercial fungicides fenfuram (70.5 %). The EC50 values of the five tested compounds against R. solani showed that compound 1e exhibited the most potent inhibition with an EC50 value of 2.824 mg/L which lower than fenfuram (EC50 = 7.691 mg/L). As a result, compound 1e could be the lead compound for the following research.
