Title: Dimethoate
CAS Registry Number: 60-51-5
CAS Name: Phosphorodithioic acid O,O-dimethyl S-[2-(methylamino)-2-oxoethyl] ester
Additional Names: phosphorodithioic acid O,O-dimethyl ester, ester with 2-mercapto-N-methylacetamide; O,O-dimethyl S-methylcarbamoylmethyl phosphorodithioate
Manufacturers' Codes: American Cyanamid 12880
Trademarks: Cygon; Fostion MM (Agrimont); Perfekthion (BASF); Rogor (Isagro); Roxion (BASF)
Molecular Formula: C5H12NO3PS2
Molecular Weight: 229.26
Percent Composition: C 26.19%, H 5.28%, N 6.11%, O 20.94%, P 13.51%, S 27.97%
Literature References: Prepn: Cassaday et al., Young, US 2494283 and US 2996531 (1950, 1961, both to Am. Cyanamid); GB 791824 (1958 to Montecatini), C.A. 52, 18222 (1958). Toxicity data: E. W. Schafer, Toxicol. Appl. Pharmacol. 21, 315 (1972). Teratogenicity study: K. D. Courtney et al., J. Environ. Sci. Health B20, 373 (1985).
Properties: Crystals, mp 52-52.5°. d65 1.277. nD65 1.5334. Burns readily on contact with flame. Very slightly sol in water. Freely sol in most organic solvents, except saturated hydrocarbons. Stable in aq soln; hydrolyzed by aq alkali. LD50 orally in rats: 250 mg/kg (Schafer).
Melting point: mp 52-52.5°
Index of refraction: nD65 1.5334
Density: d65 1.277
Toxicity data: LD50 orally in rats: 250 mg/kg (Schafer)
CAUTION: Cholinesterase inhibitor: Clinical Toxicology of Commercial Products, R. E. Gosselin et al., Eds. (Williams & Wilkins, Baltimore, 5th ed., 1984) Section II, p 297.
Use: Systemic and contact insecticide.
Dimethocaine Dimethomorph Dimethoxanate Dimethoxane Dimethyl Carbate

Dimethoate Structural Formulae .V.1.svg
CAS number 60-51-5 YesY
PubChem 3082
ChemSpider 2973 YesY
UNII W6U08B045O YesY
KEGG C14326 YesY
ChEBI CHEBI:34714 YesY
Jmol-3D images Image 1
Molecular formula C5H12NO3PS2
Molar mass 229.26 g/mol
Appearance Grey-white crystalline solid
Density 1.3 g/cm3, solid
Melting point 43–45 °C (316–318 K)
Boiling point 117 °C (390 K) at 10 Pa
Solubility in water 2.5 g/100 ml
MSDS External MSDS
GHS pictograms GHS-pictogram-exclam.svg[1]
GHS hazard statements H302 - H312[1]
GHS precautionary statements P280[1]
Main hazards Highly toxic
Flash point 107 °C; 225 °F; 380 K
Related compounds
Related organophosphates malathion
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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

Dimethoate is a widely used organophosphate insecticide used to kill insects on contact. It was patented and introduced in the 1950s by American Cyanamid. Like other organophosphates, dimethoate is an acetylcholinesterase inhibitor which disables cholinesterase, an enzyme essential for central nervous system function.