4227. Fomesafen

Nomenclature

CAS number: 72178-02-0
5-[2-Chloro-4-(trifluoromethyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide; Flex (Syngenta); Reflex (Syngenta).
C15H10ClF3N2O6S; mol wt 438.76.
C 41.06%, H 2.30%, Cl 8.08%, F 12.99%, N 6.38%, O 21.88%, S 7.31%.

Description and references

Post-emergence diphenyl ether herbicide used for early control of broad-leaf weeds in soybean and other legume crops. Prepn: D. Cartwright, D. J. Collins, EP 3416; eidem, US 4285723 (1979, 1981 both to Imperial Chemical Industries). Properties and field trial in soybeans: S. R. Colby, J. W. Barnes, Proc. 10th Int. Congr. Plant Prot. 1, 295 (1983); in green beans: C. M. Knott, Brighton Crop Prot. Conf. - Weeds 1993, 1053. Mode of selectivity and metabolism in plant crops and weeds: J. D. H. L. Evans et al., Proc. Br. Crop Prot. Conf. - Weeds 1987, 345. Metabolism and hepatoxicity in rodents: J. Krijt et al., Hum. Exp. Toxicol. 18, 338 (1999). Environmental fate in soils: J. B. Weber, Pestic. Sci. 39, 31 (1993); J. Guo et al., Water Air Soil Pollut. 148, 77 (2003). Ecotoxicological effects in aquatic systems: T. Caquet et al., Environ. Toxicol. Chem. 24, 1116 (2005).

Chemical structure

Properties

White crystalline solid, mp 220-221°. pKa 2.9. Soly in distilled water: ≈50 mg/l. LD50 orally in male, female rats (mg/kg): 1250-2000, 1600; LC50 (48, 96 hr.) in rainbow trout and bluegill (mg/l): 830, 680, 6740, 6030 (Colby).

Derivative

Sodium salt.

Nomenclature

CAS number: 108731-70-0
Flexstar (Syngenta).
C15H10ClF3N2NaO6S; mol wt 461.75.
C 39.02%, H 2.18%, Cl 7.68%, F 12.34%, N 6.07%, Na 4.98%, O 20.79%, S 6.94%.

Description and references

Percutaneous absorption: J. Hilton et al., Pharm. Res. 11, 1396 (1994).

Properties

Soly at 25° (mg/ml): propylene glycol 631; octanol 12; ethyl decanoate 10. LD50 orally (mg/kg) in male, female rats, mice: 1860, 1500, 750, 770; in female guinea pigs: 490-980; in male rabbit: 490 (Colby).

Use

Herbicide.