RESUMO
Dimesulfazet, a novel herbicide for use in paddy rice, was discovered during studies on haloalkylsulfonanilide derivatives. Our research revealed that cyclic sulfonamide derivatives exhibited herbicidal efficacy against paddy weeds prevalent in Japan, such as Schoenoplectiella juncoides (Roxb.) Lye. Furthermore, these derivatives showed efficacy against hard-to-control perennial sedges such as Eleocharis kuroguwai Ohwi. Subsequently, we converted the cyclic sulfonamide derivatives into cyclic amide derivatives, which demonstrated enhanced herbicidal activity. Among these derivatives, dimesulfazet was selected because of its exceptional efficacy against both annual and perennial sedges, while being safe for use on transplanted rice. A simple method was developed for the condensation of benzyl alcohol and cyclic amide intermediates to synthesize trifluoromethanesulfonanilide derivatives. We found that the mode of action of dimesulfazet involved the inhibition of very long-chain fatty acid biosynthesis. Dimesulfazet represents a valuable new tool for controlling S. juncoides, including biotypes resistant to acetolactate synthase inhibitors, and other perennial sedges in rice paddies. © 2024 Society of Chemical Industry.
RESUMO
Metazosulfuron is a novel sulfonylurea herbicide discovered and developed by Nissan Chemical Industries, Ltd., which exhibits excellent herbicidal activity against Echinochloa spp., annual and perennial weeds including sulfonylurea resistant biotypes in paddy fields at 60-120 g a.i./ha with good crop safety to rice. In addition, it has favorable toxicological, ecotoxicological and environmental profile. Metazosulfuron (trade name; Altair®) was registered and launched in Japan in 2013, and has been also introduced in Korea and China as of 2016. This paper describes a history of discovery, syntheses, herbicidal characteristics and crop safety of metazosulfuron.
