Methylthiophosphonic acid O -ethyl ester

Structural formula
General
Surname	Methylthiophosphonic acid O -ethyl ester
other names	EMPTA O -ethyl methylphosphonothioate Ethoxyhydroxymethylsulfanylidene phosphorane ( IUPAC )
Molecular formula	C 3 H 9 O 2 PS
External identifiers / databases
CAS number 18005-40-8 EC number 621-948-7 ECHA InfoCard 100.150.755 PubChem 556615 Wikidata Q908797
properties
Molar mass	140.14 g mol −1
Physical state	liquid
density	1.18 g cm −3
boiling point	73 ° C (1.3 h Pa )
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-311-314-331 P: 261-280-301 + 310-305 + 351 + 338-310
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Methylthiophosphonsäure- O -ethyl ester (also EMPTA from engl. O- E thyl  m ethyl p hosphono t hioic  a cid ) is an organic phosphorus compound .

The best known use of methylthiophosphonic acid O -ethyl ester is that as a possible starting material for the production of the chemical warfare agent VX . Since EMPTA cannot be easily synthesized , it is also considered a “smoking gun” for the manufacture of chemical weapons. The compound can also be formed in small quantities as a decomposition product from the hydrolysis of VX.

Methylthiophosphonic acid O- ethyl ester (as EMPTA) gained some public attention in connection with the bombing of the Asch-Schifa drug factory .

It is recorded as a Schedule 2 substance in the Chemical Weapons Convention and is therefore subject to the corresponding restrictions.

Individual evidence

1. ↑ ^{a b c d} data sheet O-Ethyl methylphosphonothioate from Sigma-Aldrich , accessed on April 10, 2011 ( PDF ).
2. ↑ NB Munro, SS Talmage, GD Griffin, LC Waters, AP Watson, JF King, V. Hauschild: The sources, fate, and toxicity of chemical warfare agent degradation products. In: Environmental health perspectives. Volume 107, Number 12, December 1999, pp. 933-974, PMID 10585900 , PMC 1566810 (free full text) (review).