7103. Penoxsulam

Nomenclature

CAS number: 219714-96-2
2-(2,2-Difluoroethoxy)-N-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-6-(trifluoromethyl)benzenesulfonamide; DE-638; Granite (Dow AgroSci.); Grasp (Dow AgroSci.); Viper (Dow AgroSci.).
C16H14F5N5O5S; mol wt 483.37.
C 39.76%, H 2.92%, F 19.65%, N 14.49%, O 16.55%, S 6.63%.

Description and references

Triazolopyrimidine sulfonamide herbicide for weed control in rice; inhibits acetolactate synthase (ALS). Prepn: T. C. Johnson et al., US 5858924 (1999 to Dow AgroSciences). Dissipation study in rice fields: D. W. Roberts et al., Proc. 12th Symp. Pestic. Chem. 2003, 349. Comprehensive review: D. Larelle et al., BCPC Int. Congr. - Crop Sci. Technol. 2003, 75-80.

Chemical structure

Properties

Tan solid, mp 223-224°. Vapor pressure (mm Hg): 7.16×10-16 at 25°, 1.87×10-16 at 20°. pKa 5.1. Soly in water at 20° (mg/l): 5.7 pH 5, 408 pH 7, 1460 pH 9. Log P (octanol/water): -0.354 (19°, unbuffered water). LD50 (mg/kg): >5000 orally in rats; >5000 dermally in rabbits. LC50 (8 day) in bobwhite quail, mallard duck (ppm): >4411, >4310. LC50 (96 hr) in rainbow trout, bluegill sunfish, common carp (mg/l): >102, >103, >101 (Larelle).

Use

Herbicide.