6251. Monocrotophos

Nomenclature

CAS number: 6923-22-4
Phosphoric acid dimethyl (1E)-1-methyl-3-(methylamino)-3-oxo-1-propenyl ester; phosphoric acid dimethyl ester, ester with (E)-3-hydroxy-N-methylcrotonamide; 3-(dimethoxyphosphinyloxy)-N-methyl-cis-crotonamide; dimethyl (E)-1-methyl-2-(methylcarbamoyl)vinyl phosphate; 3-hydroxy-N-methyl-cis-crotonamide dimethyl phosphate; azodrin; C-1414; ENT-27129; SD-9129; Phoskill (United Phosphorus).
C7H14NO5P; mol wt 223.16.
C 37.67%, H 6.32%, N 6.28%, O 35.85%, P 13.88%.

Description and references

Organophosphate insecticide; cholinesterase inhibitor. General prepn: Whetstone, Stiles, US 2802855; see also Ward, Morales, US 3400177 (1957, 1968 both to Shell). Metabolite of dicrotophos, q.v.: Menzer, Casida, J. Agric. Food Chem. 13, 102 (1965) DOI. Toxicity study: T. B. Gaines, Toxicol. Appl. Pharmacol. 14, 515 (1969) DOI PubMed. Determn of isomers in technical formulations: N. Ismail et al., J. Chromatogr. A 903, 255 (2000) DOI PubMed.

Chemical structure

Properties

Crystals, mp 54-55°. Poisonous. Commercial product is a reddish-brown solid, mp 25-30°. Vapor pressure at 20°: 7 × 106 mm Hg. Misc with water; sol in acetone, ethanol. Practically insol in diesel oils, kerosine. LD50 in male, female rats (mg/kg): 17, 20 orally; 126, 112 dermally (Gaines).

Caution

Potential symptoms of overexposure are eye irritation, miosis, blurred vision; dizziness, convulsions; dyspnea; salivation, abdominal cramps, nausea, diarrhea, vomiting. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 218.

Use

Insecticide.