5445. Leptophos

Nomenclature

CAS number: 21609-90-5
P-Phenylphosphonothioic acid O-(4-bromo-2,5-dichlorophenyl) O-methyl ester; O-(4-bromo-2,5-dichlorophenyl) O-methyl phenylphosphonothioate; O-methyl O-2,5-dichloro-4-bromophenyl phenylthiophosphonate; VCS-506; Abar; Phosvel.
C13H10BrCl2O2PS; mol wt 412.07.
C 37.89%, H 2.45%, Br 19.39%, Cl 17.21%, O 7.77%, P 7.52%, S 7.78%.

Description and references

Organophosphate insecticide; cholinesterase inhibitor. Prepn and use as an insecticide: Richter, Hanna; US 3459836, US 3551563, US 3577482 (1969, 1970, 1971, all to Velsicol). Metabolism in mice and on cotton plants: Holmstead et al., Arch. Environ. Contam. Toxicol. 1, 133 (1973) DOI PubMed. Toxicological studies in mammals: Kamel et al., J. Eur. Toxicol. 6, 70 (1973); Abou-Donia et al., Experientia 30, 63 (1974) DOI; T. B. Gaines, R. E. Linder, Fundam. Appl. Toxicol. 7, 299 (1986) DOI PubMed.

Chemical structure

Properties

Tan waxy solid. mp range 55-67°. Sp gr at 25° = 1.53. Solubility at 25° (gm/100 ml): benzene, 133; xylene, 73; acetone, 62; cyclohexane,14; heptane, 7; isopropanol, 2.4; water, 0.03 ppm. Stable to acids; hydrolyzed slowly under strongly alkaline conditions. LD50 in adult male, female rats (mg/kg): 19, 20 orally (Gaines, Linder).

Use

Insecticide.