141776-32-1

A sulfonylurea herbicide approved for use in the European Union and in some other countries. Sulfosulfuron is highly soluble in water, is semi-volatile and is mobile with a high potential for leaching to groundwater based on its physico-chemical properties. It is considered to be moderately persistent in soils and can also be persistent in water systems depending upon conditions. It may bioaccumulate but has a low mammalian toxicity. It is moderately toxic to fish, algae, earthworms and honeybees but less so to birds and aquatic invertebrates.

Sulfosulfuron pure product is odorless white solid, melting point 201.1~201.7℃. Vapor pressure 3.1×10-5mPa(20℃), 8.8×10-5mPa(25℃).KowlgP:0.73(pH 5), -0.77(pH 7), -1.44(pH 9). Relative density 1.5185 (20°C). Solubility in water (2o C, mg/L): 17.6 (pH 5), 1627 (pH 7), 482 (pH 9). Solubility in organic solvents (20°C, g/L): acetone 0.71, methanol 0.33, ethyl acetate 1.01, dichloromethane 4.35, xylene 0.16, heptane <0.01. Stability less than 14d at 54°C. Hydrolyzed DT50 (25°C): 7d (pH 4), 48d (pH 5), 168d (pH 7), 156d (pH 9). pKa 3.5 (pH 5): 17.6 (pH 7), 1627 (pH 7), 482 (pH 9). ). pKa 3.51 (20 °C).

Herbicide.

Sulfosulfuron is commercially produced via a convergent synthesis: the pyrimidine intermediate 2-amino-4-methoxy-6-methyl-1,3,5-triazine reacts with phosgene to form the corresponding isocyanate, which is coupled with 2-(ethylsulfonyl)imidazole-1-sulfonamide (prepared by oxidation of 2-(ethylthio)imidazole-1-sulfonamide with hydrogen peroxide); subsequent amination and ring closure under basic conditions yield the active compound.

Sulfosulfuron (MON 37500) is a post‐emergent herbicide for the control of grass (especially Bromus sp.) and broadleaf weeds in cereal crops at rates of 10–35 g a.i. ha−1. Sulfosulfuron was jointly developed by Monsanto Company and Takeda Chemical Industries and launched in 1997. As barley and oats are both sensitive to applications of sulfosulfuron, its use in these crops is not recommended. At rates of 20–30 g a.i. ha−1, the following weeds are controlled with at least 85% efficiency: Elymus repens, A. spica‐venti, Agrostis stolonifera, Avena fatua (North America), Bromus commutatus, B. japonicus, B. mollis, B. rigidus, B. secalinus, B. sterilis, B. tectorum, Poa bulbosa and Poa trivialis, Ambrosia artemisiifolia, Amsinckia lycopsoides, Atriplex patula, Brassica nigra, C. bursa‐pastoris, Claytonia per, Descurainia pinnata, D. sophia, Fumaria officinalis, G. aparine, Helianthus sp., Matricaria chamomilla, M. inodora, P. aviculare, P. persicaria, S. arvensis, Sisymbrium altissimum, S. media, T. arvense, and V. arvensis. In Europe, sulfosulfuron is commercially available under the trade name “Monitor®.”

Systemic, absorbed by roots and leaves and translocated. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS

Herbicide