Title:  Methyl Demeton 
CAS Registry Number:  8022-00-2 
CAS Name:  Phosphorothioic acid O-[2-(ethylthio)ethyl] O,O-dimethyl ester mixt with S-[2-(ethylthio)ethyl] O,O-dimethyl phosphorothioate 
Additional Names:  demeton-methyl;  methyl-mercaptophos;  methyl systox 
Manufacturers' Codes:  Bayer 21/116 
Trademarks:  Meta-Systox 
Molecular Formula:  C6H15O3PS2 
Molecular Weight:  230.29 
Percent Composition:  C 31.29%, H 6.57%, O 20.84%, P 13.45%, S 27.85% 
Literature References:  Cholinesterase inhibitor.  Isomeric mixture consisting of demeton-O-methyl and demeton-S-methyl (O(and S)-[2-(ethylthio)ethyl] O,O-dimethyl phosphorothioate).  Ref:  Henglein, Schrader, Z. Naturforsch. 10b, 12 (1955).  Prepn:  GB 814332 (1959 to Bayer).  Toxicology studies:  M. Vandekar, Br. J. Ind. Med. 15, 158 (1958); E. F. Edson, Pharm. J. 185, 361 (1960). 
Properties:  Commercial product is a light yellow liquid.  Hydrolyzed by alkali.  LD50 in rats (mg/kg):  50-75 orally, 300-400 dermally (Edson). 
Toxicity data:  LD50 in rats (mg/kg):  50-75 orally, 300-400 dermally (Edson) 
  
Derivative Type:  Demeton-O-methyl  
CAS Registry Number:  867-27-6 
Properties:  Colorless oil, bp0.15 74°.  d420 1.190.  nD20 1.5063.  Soly in water at room temp:  330 ppm.  Soluble in organic solvents. 
Boiling point:  bp0.15 74° 
Index of refraction:  nD20 1.5063 
Density:  d420 1.190 
  
Derivative Type:  Demeton-S-methyl  
CAS Registry Number:  919-86-8 
Properties:  Pale yellow oil, bp0.15 89°.  d420 1.207.  nD20 1.5065.  Soly in water at room temp:  3,300 ppm.  Sol in organic solvents.  LD50 in rats (mg/kg):  40 orally, 85 dermally (Edson). 
Boiling point:  bp0.15 89° 
Index of refraction:  nD20 1.5065 
Density:  d420 1.207 
Toxicity data:  LD50 in rats (mg/kg):  40 orally, 85 dermally (Edson) 
  
CAUTION:  Potential symptoms of overexposure are irritation of eyes, skin; aching eyes, rhinorrhea; nausea, headache, dizziness, vomiting.  See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 206. 
Use:  Insecticide.   |