Title: Paraoxon
CAS Registry Number: 311-45-5
CAS Name: Phosphoric acid diethyl 4-nitrophenyl ester
Additional Names: diethyl p-nitrophenyl phosphate; phosphacol
Manufacturers' Codes: E-600; Ester 25
Trademarks: Eticol; Fosfakol; Mintacol; Miotisal A; Soluglaucit
Molecular Formula: C10H14NO6P
Molecular Weight: 275.20
Percent Composition: C 43.64%, H 5.13%, N 5.09%, O 34.88%, P 11.26%
Literature References: Prepd by the action of diethyl chlorophosphate on sodium p-nitrophenolate or by nitration of diethyl phenyl phosphate: Schrader, BIOS Final Report No. 714, 52 (1947); Angew. Chem. 62, 471 (1950); CH 257649 (1949); Fagerlind et al., Sven. Farm. Tidskr. 56, 303, C.A. 46, 9259. Physical properties: E. F. Williams, Ind. Eng. Chem. 43, 950 (1951). Formation from parathion on citrus foliage and soil surface: R. C. Spear et al., J. Agric. Food Chem. 23, 808 (1975); W. F. Spencer et al., Bull. Environ. Contam. Toxicol. 14, 265 (1975). Toxicity study: W. R. Pickering, J. C. Malone, Biochem. Pharmacol. 16, 1183 (1967). Brief review: G. Schrader, Die Entwicklung neuer insektizider Phosphorsäure-Ester (Verlag Chemie, Weinheim, 1963) pp 259-272.
Properties: Oily liq. Slight odor. Poisonous! bp1.0 169-170°. d425 1.2683. nD20 1.50959. uv max: 274 nm (e 8.9´103). Soly in water (25°): 2400 mg/mL. Freely sol in ether, other organic solvents. Aq solns are stable up to pH 7. Roughly 300 times more stable to hydrolysis than tetraethyl pyrophosphate. The uncatalyzed reaction with water is very small and the overall velocity constant is K = 0.52[OH] + 1´10-6 min-1. See: Coates, Ann. Appl. Biol. 36, 158 (1949). LD50 orally in rats: 1.8 mg/kg (Pickering, Malone).
Boiling point: bp1.0 169-170°
Index of refraction: nD20 1.50959
Absorption maximum: uv max: 274 nm (e 8.9´103)
Density: d425 1.2683
Toxicity data: LD50 orally in rats: 1.8 mg/kg (Pickering, Malone)
CAUTION: Cholinesterase inhibitor. For symptoms see Parathion.
Use: Insecticide. |