Description
Foramsulfuron is a sulfonylurea selective, post-emergence herbicide for grass and broadleaved weed control. It is highly soluble in water and has a low volatility. It is not normally persistent in soil or water systems but does have the potential to leach to groundwater depending on local conditions. There are no serious concerns about its toxicity to humans. Toxicity to biodiversity is generally classified as low to moderate.
Definition
ChEBI: A member of the class of benzamides that is N,N-dimethylbenzamide substituted by a formylamino group at position 4 and a [(4,6-dimethoxypyrimidin-2-yl)carbamoyl]sulfamoyl group at position 2.
Production Methods
Foramsulfuron is commercially produced through a multi-step synthesis involving sulfonyl chloride intermediates and pyrimidine derivatives. It begins with the reaction of 2-(dimethylaminoformyl)-5-formamidobenzenesulfonyl chloride with sodium cyanate in a suitable solvent, typically under stirring and catalytic conditions to form a key sulfonylurea intermediate. This intermediate is then reacted with 2-amino-4,6-dimethoxypyrimidine, which introduces the pyrimidine moiety essential for herbicidal activity. The reaction is carried out under controlled temperature and pH to ensure efficient coupling and minimal by-product formation.
Agricultural Uses
Foramsulfuron (AE F130360) is a post-emergence sulfonylurea herbicide used for the control of major grass species and certain broadleaf weeds in maize. It is applied with the safener isoxadifen‐ethyl (AE F122006) and in some products in combination with small quantities iodosulfuron-methyl-sodium.
Introduced in 2001 and subsequently commercialized by Bayer CropScience, the three‐way mixture of foramsulfuron with iodosulfuron-methyl-sodium and isoxadifen-ethyl is used for post‐emergent weed control in maize. Foramsulfuron, at a dose rate of 30–45 g a.i. ha−1, offers a minimum of 90% weed control on most grassy weeds, such as E. crus-galli, Setaria spp., Agropyron repens, A. spica‐venti, A. myosuroides, L. multiflorum, Panicum dichotomiflorum, P. annua, and Sorghum halepense, and a wide selection of broadleaf weed species, such as A. theophrasti, Amaranthus spp., Galinsoga parviflora, L. purpureum, S. nigrum, and S. media. The addition of 1–2 g a.i. ha−1 of iodosulfuron-methyl-sodium improves the level of weed control on broadleaf weed species, including C. album, G. aparine, Fallopia convolvulus, Ipomoea spp., P. aviculare, P. lapathifolium, S. arvensis, and Xanthium strumarium.
The basis of selectivity of foramsulfuron in the presence of the safener isoxadifen-ethyl is a more rapid rate of metabolic detoxification in maize compared with target weeds, in which little or no degradation of the parent sulfonylurea occurs. Three main routes of metabolism have been established in maize: a hydrolytic cleavage of the sulfonylurea bridge, a deformylation of the amino group, and oxidative metabolism of the dimethoxypyrimidine ring.
Foramsulfuron is commercialized with the safener isoxadifen-ethyl under the trade names “Option®” and “Equip®,” whereas in combination with iodosulfuron-methyl-sodium, the ternary mixture is sold as “MaisTer®,” “Mester®,” “Fortuna®” or “Equip Plus,” and “Option 360”. The combination of the two herbicides probably makes “MaisTer” and “Mester” the widest-spectrum maize herbicides used in Europe today.
Agricultural Uses
Herbicide: Used on athletic fields and recreational areas, including golf courses (for turf), lawns, etc. Used on corn.
An acetolactate syntheses inhibitor.
