4907. Imazethapyr

Nomenclature

CAS number: 81335-77-5
2-[4,5-Dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid; (±)-5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-1H-imidazolin-2-yl)nicotinic acid; AC-263499; CL-263499.
C15H19N3O3; mol wt 289.33.
C 62.27%, H 6.62%, N 14.52%, O 16.59%.

Description and references

Selective imidazolinone herbicide. Inhibitor of acetolactate synthase, a key enzyme in the biosynthesis of branched chain amino acids. Prepn: M. Los, EP 41623; idem, US 4798619 (1981, 1989 both to Am. Cyanamid). Comprehensive description: T. R. Peoples et al., Proc. Br. Crop Prot. Conf. - Weeds 1985, 99-106. Determn in soil: O. Nováková, Chromatographia 39 62 (1994). Metabolism in corn: N. M. Mallipudi et al., J. Agric. Food Chem. 42, 1213 (1994).

Chemical structure

Properties

White to off-white crystalline solid, mp 172-175°. pK1 2.1; pK2 3.9. Soly in water (25°): 1415 ppm. LD50 orally in rats and mice: >5000 mg/kg; dermally in rabbits: >2000 mg/kg (Peoples).

Derivative

Ammonium salt.

Nomenclature

CAS number: 101917-66-2
Pivot (BASF); Pursuit (BASF).
C15H22N4O3; mol wt 306.36.
C 58.81%, H 7.24%, N 18.29%, O 15.67%.

Use

Herbicide.