Research and development of a novel rice herbicide, pyrimisulfan^#

Abstract

Pyrimisulfan is a novel paddy herbicide that was discovered and developed by Kumiai Chemical Industry Co., Ltd.; Ihara Chemical Industry Co., Ltd.; and K-I Chemical Research Institute Co., Ltd. It was registered in Japan in 2010 and launched the first one-shot herbicide containing only one active ingredient (a.i.) developed with our original formulation technology. The compound is sulfonanilide, having a pyrimidinyl-containing group at the 2′-position and an acetolactate synthase (ALS) inhibitor. Pyrimisulfan shows broad-spectrum weed control against annual grass, sedge, broadleaf, and sulfonylurea-resistant weeds without causing phytotoxic injury to rice. At doses of 50-75 g a.i./ha, pyrimisulfan has a wide application window and exhibits long residual activity against these weeds. Pyrimisulfan has favorable toxicological, ecotoxicological, and environmental profiles.

Exploration of new reaction tools for late-stage functionalization of complex chemicals

“…180 After exploration of the optimal conditions, identified as arene (1.0 equiv), PhSO 2 SCF 2 H (2.0 equiv), TBAI To demonstrate the practicality of this method, the late-stage modification was performed to furnish the corresponding difluoromethylsulfoxides (48b'') and difluoromethylsulfones (48b'), which were both identified as valuable entities in medicinal chemistry (Scheme 30a). [181][182] Other thiolation moieties, e.g., phenyl-(77b) and naphthylthiol (78b), proceed successfully, endowing this method with appreciable With regards to the mechanistic insight, we performed trapping experiments which suggested a radical process (Scheme 31). In the presence of radical-clock type reagent, the ring-closure product was isolated (81b).…”

Development of novel pesticides in the 21st century

“…Pyrimisulfan is the first one-shot herbicide for rice containing only one active ingredient, with an original formulation technology. 93) In addition, it can control other troublesome weeds, including Sagittaria trifolia, Scirpus nipponicus, Bolboschoenus maritimus, Eleocharis kuroguwai, and sulfonylurearesistant weeds, which have presented serious problems in recent years.…”

Applications of Bioisosteres in the Design of Biologically Active Compounds

“…Agricultural chemistry has been a source of interesting constellations of functionality, several of which have subsequently been embraced by the medicinal chemistry community where they have often been exploited in the context of bioisosterism. Several marketed agricultural products contain elements and functionalities not yet represented in approved drugs, including the silicon atoms in the antifungal agent flusilazole ( 1 ) and the insecticide silafluofen ( 2 ), the sulfoximine moiety that is a hallmark of the insecticide sulfoxaflor ( 3 ), the 1,1,1,2,3,3,3-heptafluoropropan-2-yl substituent in the insecticide flubendiamide ( 4 ), and the differentially configured difluoromethylated motifs found in the herbicides pyrimisulfan ( 5 ) and sulfentrazone ( 6 ). − However, all of these motifs have been exemplified in the medicinal chemistry arena where they have often been associated with studies involving bioisostere design. − There are many structural elements that are highly prevalent in medicinal chemistry that only sparsely populate the agricultural chemistry field, most notably the piperazine heterocycle, which is heavily represented in marketed drugs and which has been the subject of extensive study in the context of bioisostere design. ,,, The paucity of piperazines in agricultural chemicals is believed to be related to the general observation of an absence of basic moieties because of a negative impact on bioavailability . In this synopsis of applications of bioisosteres in the design of biologically active compounds, we will provide a flavor of motifs with practical importance in drug design while highlighting some of those that originated in the agricultural chemistry field.…”