Abstract: Sulfonylurea herbicides have been applied worldwide in agriculture. Some sulfonylurea residues might exist in soil longer than that people expected. However, flupyrsulfuron-methyl-sodium which was firstly reported as a new 5-substituted sulfonylurea herbicide has less than one month residual life. Therefore, 5-substituted benzenesulfonylureas are potential molecules to regulate its residual situation. In order to develop new sulfonylurea derivatives, the substituent on the critical 5-posotion of the benzene ring was optimized. On the basis of our former work on sulfonylureas which contains a characteristic mono-substituted pyrimidine moiety, twenty-six new sulfonylurea derivatives were synthesized and their structures were confirmed by 1H NMR, 31P NMR and elemental analysis. The greenhouse bioassay tests show that some title compounds exhibit potent herbicidal activity.

Key words: Sulfonylurea, 5-Substituted phenyl ring, Herbicidal activity