6154. Metribuzin

Nomenclature

CAS number: 21087-64-9
4-Amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one; 4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one; Bay 94337; Lexone (DuPont); Sencor (Bayer CropSci.); Sencoral (Bayer CropSci.).
C8H14N4OS; mol wt 214.29.
C 44.84%, H 6.59%, N 26.15%, O 7.47%, S 14.96%.

Description and references

Pre- and post-emergence triazone herbicide. Prepn: BE 697083; K. Westphal et al., US 3671523 (1967, 1972 both to Bayer AG). Physicochemical properties, toxicology and herbicidal activity: L. Eue, Pflanzenschutz-Nachr. 25, 175 (1972). Toxicity data: E. Loeser, G. Kimmerle, ibid. 186. HPLC determn in plant tissues: C. E. Parker, G. H. Degen, J. Liq. Chromatogr. 6, 725 (1983).

Chemical structure

Properties

White crystalline solid, mp 125-126.5°. d420 1.28. Vapor pressure at 20°: <105 mm Hg. Sol in methanol, ethanol. Soly in water: 1200 ppm. LD50 orally in rats: 2200 mg/kg; LC50 in rainbow trout: >10 ppm (Loeser, Kimmerle).

Caution

Potential symptoms of overexposure in exptl animals are CNS depression; thyroid, liver and enzyme changes. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 216.

Use

Herbicide.