Title: Mesotrione
CAS Registry Number: 104206-82-8
CAS Name: 2-[4-(Methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione
Manufacturers' Codes: ZA-1296
Trademarks: Callisto (Syngenta)
Molecular Formula: C14H13NO7S
Molecular Weight: 339.32
Percent Composition: C 49.55%, H 3.86%, N 4.13%, O 33.01%, S 9.45%
Literature References: Triketone herbicide for use in maize; inhibits
p-hydroxyphenylpyruvate dioxygenase (HPPD). Synthetic mimic of
leptospermone, a natural herbicide produced by the bottlebrush plant,
Callistemon citrinus Stapf. Prepn: C. G. Carter,
EP 186118 (1986 to Stauffer);
idem,
US 5006158 (1991 to ICI). Comprehensive description: R. A. Wichert
et al., Brighton Crop Prot. Conf. - Weeds 1999, 105-110. HPLC determn in crops, soil, water: P. Alferness, L. Wiebe,
J. Agric. Food Chem. 50, 3926 (2002). Adsorption and degradation in soil: J. S. Dyson
et al.,
J. Environ. Qual. 31, 613 (2002).
Review: G. Mitchell
et al., Pest Manage. Sci. 57, 120-128 (2001).
Properties: Opaque solid, mp 165°. pKa (20°): 3.12. Vapor pressure (20°): 4.27 ′ 10-8 mm Hg. Soly in water at 20° (g/l): 2.2 (pH 4.8); 15 (pH 6.9); 22 (pH 9). LD50 in rats (mg/kg): >5000 orally; >2000 dermally. LC50 in rats (mg/l): >5 by inhalation. LC50 (96 hr) in bluegill sunfish, rainbow trout (mg/l): >120, >120 (Wichert).
Melting point: mp 165°
pKa: pKa (20°): 3.12
Toxicity data: LD50 in rats (mg/kg): >5000 orally; >2000 dermally; LC50 in rats (mg/l): >5 by inhalation; LC50 (96 hr) in bluegill sunfish, rainbow trout (mg/l): >120, >120
Use: Herbicide.