4108. Florasulam

Nomenclature

CAS number: 145701-23-1
N-(2,6-Difluorophenyl)-8-fluoro-5-methoxy-[1,2,4]triazolo[l,5-c]pyrimidine-2-sulfonamide; 2′,6′,8-trifluoro-5-methoxy-s-triazolo[1,5-c]pyrimidine-2-sulfonanilide; Boxer (Dow AgroSci.); Nikos (Dow AgroSci.); Primus (Dow AgroSci.).
C12H8F3N5O3S; mol wt 359.28.
C 40.12%, H 2.24%, F 15.86%, N 19.49%, O 13.36%, S 8.92%.

Description and references

Triazolopyrimidine herbicide for use in cereals. Acetolactate synthase (ALS) inhibitor. Prepn: J. C. Van Heertum et al., WO 8911782 (1989 to Dow); eidem, US 5163995 (1992 to DowElanco). Comprehensive description: A. R. Thompson et al., Brighton Crop Prot. Conf. - Weeds 1999, 73-80. Review of field trials: A. D. Bailey et al., ibid. 205-209. Photolytic degradation in soil and water: M. S. Krieger et al., J. Agric. Food Chem. 48, 3710 (2000).

Chemical structure

Properties

mp 220-221° (dec) (Van Heertum); also reported as 193.5-230.5° (Thompson). pKa: 4.54. Partition coefficient (octanol/water): 0.060 (pH 7.0). Vapor pressure (25°): 1 × 105 Pa. Soly in water (20°): 6.36 g/l (pH 7.0). LD50 in rat, quail (mg/kg): >6000, 1046 orally; percutaneously in rabbit: >2000 mg/kg. LC50 in rainbow trout, bluegill (96 hr): >96, >98 mg/l (Thompson).

Use

Herbicide.