Synthesis and biological activity of N-substituted phenyl-1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethylcarbamate

In order to find highly active triazole phenyl carbamate derivatives, 1,2,4-triazole and 2-chloro-2,4-difluoroacetophenone were used as raw materials, and the strategy of active substructure splicing was adopted, eighteen N-substituted phenyl-1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethyl carbamate derivatives 6a-6r were designed and synthesized. Their structures were confirmed by ¹H NMR, ¹³C NMR and high resolution mass spectrometry (HRMS). The results of fungicidal activity assay showed that compound 6m had a good inhibitory effect on the 6 tested fungi at 100 μmol/L with a inhibition rate of more than 50%. The EC₅₀ value of compound 6p against Sclerotinia sclerotiorum was 7.1 μmol/L, the fungicidal activity was higher than that of the control compound diniconazole (EC₅₀ value was 9.1 μmol/L). The results of acaricidal activity showed that at 150 μmol/L, the lethal rates of compounds 6h , 6k and 6o were 67.7%, 74.9% and 57.5% for Tetranychus cinnabarinus at 48 h, respectively, and the acaricidal activity was lower than that of the control compound abamectin B1a (100%). The compound 6o synthesized in this study has both fungicidal and acaricidal activities, which can provide a reference for the design and research of novel fungicidal and acaricidal triazole compounds.