Abstract:In order to discover new compounds with high bactericidal activity and broad inhibition, fifteen series of new 2-substituted-4-chloro-5-aryl-2H-1,2,3-triazole derivatives were synthesized using aryl aldehyde, nitromethane and sodium azide as starting materials through cyclization, chlorination and alkylation reactionin. The structures of title compounds were confirmed by 1H NMR, 13C NMR, mass spectra and elemental analyses. The in vitro antifungal activities of target compound were evaluated against six phytopathogenic fungi (Gibberella zeae, Phytophythora capsici, Alternaria alternate, Botrytis cinerea, Rhizoctonia solani and Sclerotonia sclerotiorum) using the mycelium growth rate method under the test concentration of 25 mg/L. The results of bioassay showed that some compounds exhibited excellent fungicidal activities. For example, the inhibition rates of compound 4d against Gibberella zeae, Botrytis cinerea and Sclerotonia sclerotiorum were 70.4%, 74.1% and 72.9%, respectively. The inhibition rates of compound 4k against Botrytis cinerea and Sclerotonia sclerotiorum were 87.0% and 84.7% respectively. The inhibition rate of 4d against Phytophythora capsici was 61.4%, which was higher than that of commercial difenoconazole 42.5%.