Synonyms:ethyl 5-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-1-methylpyrazole-4-carboxylate (IUPAC)
CAS No.: 93697-74-6
Molecular Weight: 414.3922
Molecular Formula: C14H18N6O7S
Form Colourless crystals.
M.p. 177.8–179.5 °C
V.p. 4.2 × 10-5 mPa (25 °C)
S.g./density 1.46 (20 °C)
Solubility: In water 9.76 mg/l (20 °C). methanol 4.32, hexane 0.0185, benzene 15.6(all in g/l, 20 °C).
Stability: Stable at 50 °C for 6months. Relatively stable at pH 7. Unstable in acidic or alkaline media. pKa 3.7
Pyrazosulfuron-Ethyl is a branched chain amino acid synthesis (ALS or AHAS) inhibitor, acting by inhibiting biosynthesis of the essential amino acids valine and isoleucine, hence stopping cell division and plant growth. Selectivity derives from rapid metabolism (demethylation of methoxy group) in the crop. Systemic herbicide, absorbed by roots and/or leaves and translocated to the meristems. Used to control of annual and perennial broad-leaved weeds and sedges, pre- or post-emergence, in wet-sown and transplanted rice crops
7.5% WP; 10% WP; 95% TC and other formulations
Pouch, bag, drum
Risks and Safety Information
Class 9, hazard to environment
Oral Acute oral LD50( rats and mice) >5000mg/kg. Skin and eye Acute percutaneous LD50(rats) >2000mg/kg. Non-irritating to skin and eyes (rabbits). Non-sensitising to skin (guinea pigs).
Birds Acute oral LD50(bobwhite quail) >2250mg/kg. Fish LC50 (96h for rainbow trout and bluegill sunfish) >180mg/l