Title: Demeton
CAS Registry Number: 8065-48-3
CAS Name: Phosphorothioic acid O,O-diethyl O-[2-(ethylthio)ethyl] ester mixture with O,O-diethyl S-[2-(ethylthio)ethyl]phosphorothioate
Additional Names: mercaptophos
Manufacturers' Codes: Bayer 8169; E-1059
Trademarks: Systox
Molecular Formula: C8H19O3PS2
Molecular Weight: 258.34
Percent Composition: C 37.19%, H 7.41%, O 18.58%, P 11.99%, S 24.82%
Literature References: Cholinesterase inhibitor. Isomeric mixture consisting of demeton-O and demeton-S (O,O-diethyl O(and S)-ethylmercaptoethyl thiophosphates). Another name for demeton-S is Isosystox. Prepn: Schrader, US 2571989 and US 2597534 (1951, 1952 both to Bayer); Gardner, Heath, Anal. Chem. 25, 1849 (1953). Toxicity study: T. B. Gaines, Toxicol. Appl. Pharmacol. 14, 515 (1969).
Properties: Oily liq. Faint odor. bp2 134°. Virtually insol in water. Sol in ethanol, propylene glycol, toluene and similar hydrocarbons. Absorbed by plants, rendering the foliage and plant fluids toxic to insects. LD50 in female, male rats (mg/kg): 2.5, 6.2 orally; 8.2, 14 dermally (Gaines).
Boiling point: bp2 134°
Toxicity data: LD50 in female, male rats (mg/kg): 2.5, 6.2 orally; 8.2, 14 dermally (Gaines)
CAUTION: Potential symptoms of overexposure are miosis, aching eyes, rhinorrhea and headache; chest tightening, wheezing, laryngeal spasms, salivation and cyanosis; anorexia, nausea, vomiting, abdominal cramps and diarrhea; local sweating; muscle fasciculation, weakness and paralysis; giddiness, confusion and ataxia; convulsions, coma; low blood pressure; cardiac irregularities; irritation of eyes and skin. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 90.
Use: Insecticide.
Demexiptiline Denatonium Benzoate Dendrotoxins Denileukin Diftitox Denopamine

Demeton -Molecule-3D-balls-by-AHRLS.png
Demeton-S Structural Formula V.1.svg
CAS number 126-75-0 N
PubChem 24723
ChemSpider 23115 YesY
Jmol-3D images Image 1
Molecular formula C8H19O3PS2
Molar mass 258.3384
Appearance colorless oil
Density 1.146 g/cm3
Boiling point 128 °C; 262 °F; 401 K
Solubility in water 2.0 g/100 mL
Refractive index (nD) 1.5
Flash point 147.6 °C; 297.7 °F; 420.8 K
LD50 1.5 mg/kg (oral, rat)
Related compounds
Related Organothiophosphate insecticides Demeton-S-methyl
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Demeton is a phosphorothioate insecticide with the chemical formula C8H19O3PS2.