Dimethylphosphite

Dimethylphosphite
Names
	Preferred IUPAC name Dimethyl phosphonate
	Other names Phosphonic acid, dimethyl ester
Identifiers
CAS Number	868-85-9 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL65359;
ChemSpider	85582;
ECHA InfoCard	100.011.622
PubChem CID	94853;
UNII	ST4TBO000H ;
CompTox Dashboard (EPA)	DTXSID5020493 ;
	InChI InChI=1S/C2H7O3P/c1-4-6(3)5-2/h3H,1-2H3 Key: DLQDGVZAEYZNTG-UHFFFAOYSA-N;
	SMILES COP(O)OC;
Properties
Chemical formula	C2H7O3P
Molar mass	110.049 g·mol−1
Appearance	colorless liquid
Density	1.20 g/cm3
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
	Infobox references

Dimethyl hydrogen phosphite (DMHP), also known as Dimethylphosphite, is an organophosphorus compound with the formula (CH₃O)₂P(O)H. It is a reagent for generating other organophosphorus compounds, exploiting the high reactivity of the P-H bond. The molecule is tetrahedral. It is a colorless liquid. The compounds can be prepared by methanolysis of phosphorus trichloride or by heating diethylphosphite in methanol.^[1]

Due to the presence of hydrogen, a "soft" ligand, the compound resonates. DMHP exists in chemical equilibrium, in two structures. One of the structures has a lone electron cloud, which is nucleophilically attacking the remaining tetrahedral structure. Due to the structural equilibrium tending towards the phosphonate, this reaction is slow, needing a chemical or electromagnetic catalyst (heat).

This tautomeric nature of DMHP made it desirable as a precursor to the G-series compounds, and it was the most successful among all other phosphonate precursors.^[2] The now obsolete process, which used it as a precursor, was called the DMHP process, investigated by Otto Ambros' team and implemented to scale sarin production.^[3]

References[]

^ Balint, Erika; Tajti, Adam; Drahos, Laszlo; Ilia, Gheorge; Keglevich, Gyorgy (2013). "Alcoholysis of Dialkyl Phosphites Under Microwave Conditions". Current Organic Chemistry. 17: 555–562.CS1 maint: uses authors parameter (link)
^ Sipri - Chemical Weapons: Destruction and Conversion. p 57-62
^ Mark A. Prelas, Dabir S. Viswanath,. Science and Technology of Terrorism and Counterterrorism, Second Edition. p 341-342.

[1] Balint, Erika; Tajti, Adam; Drahos, Laszlo; Ilia, Gheorge; Keglevich, Gyorgy (2013). "Alcoholysis of Dialkyl Phosphites Under Microwave Conditions". Current Organic Chemistry. 17: 555–562.CS1 maint: uses authors parameter (link)

[2] Sipri - Chemical Weapons: Destruction and Conversion. p 57-62

[3] Mark A. Prelas, Dabir S. Viswanath,. Science and Technology of Terrorism and Counterterrorism, Second Edition. p 341-342.

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