4141. Flumetsulam

Nomenclature

CAS number: 98967-40-9
N-(2,6-Difluorophenyl)-5-methyl[1,2,4]triazolo-[1,5-a]pyrimidine-2-sulfonamide; DE-498; Broadstrike (Dow AgroSci.); Python (Dow AgroSci.).
C12H9F2N5O2S; mol wt 325.29.
C 44.31%, H 2.79%, F 11.68%, N 21.53%, O 9.84%, S 9.86%.

Description and references

Selective inhibitor of acetolactate synthase, a key enzyme in branched chain amino acid biosynthesis. Prepn: W. A. Kleschick et al., EP 142152 (1985 to Dow). Improved process: L. H. McKendry, US 4910306 (1990 to Dow). Synthesis, toxicity and herbicidal activity: W. A. Kleschick et al., J. Agric. Food Chem. 40, 1083 (1992). Degradation in soil: R. G. Lehmann et al., Weed Res. 33, 187 (1993). Metabolism in wheat, corn and barley: D. S. Frear et al., Pestic. Biochem. Physiol. 45, 178 (1993).

Chemical structure

Properties

White powder, mp 250-251°. pKa 4.6. Partition coefficient (octanol/water): 0.21. Vapor pressure (25°): 3.7 × 1013 Pa. Soly in water (g/l): 0.049 (pH 2.5); 5.65 (pH 7). LD50 in rats (mg/kg): >5000 orally; in rabbits (mg/kg): >2000 dermally (Kleschick, 1992).

Use

Herbicide.