Design,Synthesis and Herbicidal Activity of Novel Sulfonylureas Containing Triazole and Oxadiazole Moieties

Three novel series of 5-substituted sulfonylurea derivatives were designed and synthesized via introducing a triazole or oxadiazole ring at the 5th position of the benzene ring in classical sulfonylurea herbicides. All the target compounds were confirmed by means of ¹H nuclear magnetic resonance(NMR), ¹³C NMR and elemental analysis. The bioassay results show that the target compounds containing an oxadiazole ring at the 5th position display moderate to excellent herbicidal activities against Brassica campestris and Amaranthus retroflexus under soil treatment. Especially, compounds zdk20, zdk21 and zdk22 possess 98.6%, 96.5% and 94.5% inhibition rates, respectively, against Amaranthus retroflexus at a concentration of 75 g/ha(1 ha=1×10⁴ m²) under soil treatment, which approach to those of the commercial herbicide chlorsulfuron.