Abstract:
To discover compounds with better fungicidal activity, a series of
N-phenylacetamide derivatives (
6a-
6o) containing 1,2,4-triazoles were designed and synthesized by combining substituted
N-phenylacetamide with 1-(2,4-difluorophenyl)-2-(1
H-1,2,4-triazol-1-yl)-ethanol using an ether bridge. Their structures were confirmed by
1H NMR,
13C NMR, and HRMS analyses. The results of indoor fungicidal activity determination using the mycelial growth rate method showed that compound
6j had an EC
50 value of 0.15 mg/L for
Bipolaris maydis, with indoor toxicity comparable to that of the control agent diniconazole (0.12 mg/L). The EC
50 value of compound
6a for
Rhizoctonia solani was 6.96 mg/L, and its indoor toxicity is lower than that of the control agent diniconazole (1.88 mg/L). However, the potted results showed that at concentrations of 200 and 100 mg/L, the protective efficacy of compound
6a against rice sheath blight was 76.65% and 43.92%, respectively, which were higher than those of diniconazole (68.03% and 42.02%). The curative efficacy was 78.90% and 45.05%, respectively, which were higher than those of diniconazole (75.56% and 42.34%). The synthesized target compounds in this study have certain fungicidal activities, thereby enriching the structural types of triazole fungicides.