In order to search for ecologically-safer and environmentally-benign sulfonylurea herbicides, on the basis of study on the N-(4-methy1pyrimidin-2-y1)-N'-(2-methoxycarbonyl phenylsulfonyl)urea, named monosulfuron, a commercialized herbicide invented by our laboratory, 26 novel benzenesulfonylurea compounds modified at the 5-position of the benzene ring were synthesized. The structures of all compounds synthesized were confirmed by elemental analysis, MS and ¹H NMR spectra. Herbicidal activity of the new compounds was determined by rape disc and pot bioassay experiments. The result indicated that when the substituent group at 5-position of the benzene ring was benzamide, the herbicidal activity was good compared to sulfometuron-methyl.

Key words: 5-substituted phenyl ring, benzene sulfonylurea, synthesis, herbicidal activity