4905. Imazapyr

Nomenclature

CAS number: 81334-34-1
2-[4,5-Dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridinecarboxylic acid; 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid.
C13H15N3O3; mol wt 261.28.
C 59.76%, H 5.79%, N 16.08%, O 18.37%.

Description and references

Inhibitor of acetolactate synthase, a key enzyme in branched chain amino acid biosynthesis. Prepn: M. Los, EP 41623; idem, US 4798619 (1981, 1989 both to Am. Cyanamid). Description: R. Paxman et al., Proc. 38th N. Z. Weed Pest Control Conf., 73 (1985). Mode of action: D. Shaner et al., Proc. Br. Crop Prot. Conf. - Weeds 1985, 147. Determn in soil: O. Nováková, Chromatographia 39, 62 (1994). Persistence in soil: S. Vizantinopoulos, P. Lolos, Bull. Environ. Contam. Toxicol. 52, 404 (1994). Field trials in sod: K. A. Griffin et al., Crop Sci. 34, 202 (1994).

Chemical structure

Properties

Crystals from acetone + hexane, mp 170-172.5°. pK1 1.9; pK2 3.6. Soly in water (pH 7): ≈1.0 g/l. LD50 orally in rats: >5000 mg/kg; dermally in rabbits: >2000 mg/kg (Paxman).

Derivative

Isopropylamine salt.

Nomenclature

CAS number: 81510-83-0
AC-252925; CL-252925; Arsenal (BASF); Chopper (BASF).
C13H15N3O3.C3H9N; mol wt 320.39.
C 59.98%, H 7.55%, N 17.49%, O 14.98%.

Properties

mp 160-180° (dec).

Use

Herbicide.