6907. Oxadiazon

Nomenclature

CAS number: 19666-30-9
3-[2,4-Dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3H)-one; 2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one; 5-tert-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazolin-2-one; RP-17623; Ronstar (Rh^one-Poulenc).
C15H18Cl2N2O3; mol wt 345.22.
C 52.19%, H 5.26%, Cl 20.54%, N 8.11%, O 13.90%.

Description and references

Selective pre-emergence herbicide. Prepn: J. Metivier, R. Boesch, US 3385862 (1968 to Rh^one Poulenc). Metabolism: A. Guardigli et al., Arch. Environ. Contam. Toxicol. 4, 145 (1976). Persistence in soil: D. Ambrosi et al., J. Agric. Food Chem. 25, 868 (1977). Efficacy and phytotoxicity: G. W. Knox, Proc. Fla. State Hort. Soc. 99, 270 (1986). Weed control: S. S. Lim, Proc. Nat. Semin. Workshop Rice Field Weed Mgmt. 1988, 169.

Chemical structure

Properties

White, odorless, non-hygroscopic crystals, mp 88-90°. Vapor pressure at 20°: <1 × 10-6 mm Hg. Soly at 20° (g/l): water ≈0.0007; ethanol, methanol ≈100; cyclohexanone ≈200; acetone, acetophenone, anisole carbon tetrachloride, isophorone, methylethylketone ≈600; benzene, chloroform, methylene chloride, toluene ≈1000. LD50 orally in rats, bobwhite quail, mallard duck: 8000, 6000, 1000 mg/kg (Lim).

Use

Herbicide.