Synthesis and Structure-activity Relationships of Herbicidal Thiophene Sulfonylurea Compounds

Abstract

In a study of sulfonylurea herbicides, we found that some thiophene sulfonylureas, substituted at the 3 position and possessing the sulfonylurea bridge at the 2 position of the thiophene ring, exhibit high herbicidal activities on paddy field application. Although most of them are phytotoxic to rice (Oryza sativa), introduction of a fluorine atom onto the substituent attached at the 3 position of the thiophene moiety improved the selectivity to rice. Namely, N-{(4, 6-dimethoxypyrimidin-2-yl)aminocarbonyl}-3-{(2, 2, 2-trifluoroethoxy)methyl}-2-thiophenesulfonamide and N-{(4, 6-dimethoxypyrimidin-2-yl)-aminocarbonyl}-3-{(2-fluoroethoxy)methyl}-2-thiophene sulfonamide were selected as good herbicides for paddy field application.