Selective Herbicidal Activities of Ethyl 5-(4, 6-Dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-1-methylpyrazole-4-carboxylate and Its Related Compounds

Abstract

Twenty-six derivatives of pyrazole-5-sulfonylureas were synthesized and investigated for their herbicidal activities. The title compound, pyrazosulfuron-ethyl (5, code No. NC-311), was found the best compound that was highly effective in controlling paddy weeds, especially annual and perennial broad-leaf weeds and sedges. In the paddy-field trial, 5 effectively controlled weeds at the rate of 20-30g a. i./ha without phytotoxicity to transplanted rice. This herbicide is proposed as a potent novel herbicide to protect paddy rice.