Trimethyl phosphate

Trimethyl phosphate
Names
	Preferred IUPAC name Trimethyl phosphate
	Other names Phosphoric acid trimethyl ester; Methyl phosphate, tribasic; Trimethoxyphosphine oxide; Trimethyl orthophosphate fraction
Identifiers
CAS Number	512-56-1 ;
3D model (JSmol)	Interactive image;
Abbreviations	TMP
Beilstein Reference	1071731
ChEBI	CHEBI:46324 ;
ChemSpider	10101 ;
ECHA InfoCard	100.007.405
Gmelin Reference	49926
PubChem CID	10541;
RTECS number	TC8225000;
UNII	Z1E45TMW1Z ;
CompTox Dashboard (EPA)	DTXSID1021403 ;
	InChI InChI=1S/C3H9O4P/c1-5-8(4,6-2)7-3/h1-3H3 Key: WVLBCYQITXONBZ-UHFFFAOYSA-N ; InChI=1/C3H9O4P/c1-5-8(4,6-2)7-3/h1-3H3 Key: WVLBCYQITXONBZ-UHFFFAOYAV;
	SMILES O=P(OC)(OC)OC;
Properties
Chemical formula	(CH3O)3PO
Molar mass	140.08
Appearance	Colorless liquid
Melting point	−46 °C (−51 °F; 227 K)
Boiling point	197 °C (387 °F; 470 K)
Solubility in water	good
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H315, H318, H319, H340, H350, H351, H361, H373
Precautionary statements	P201, P202, P260, P264, P270, P280, P281, P301 P312, P302 P352, P305 P351 P338, P308 P313, P310, P314, P321, P330, P332 P313, P337 P313, P362, P405, P501
NFPA 704 (fire diamond)	2 1 0
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Trimethyl phosphate is the trimethyl ester of phosphoric acid. It is a colourless, nonvolatile liquid. It has some specialized uses in the production of other compounds.^[1]

Production

Trimethyl phosphate is prepared by treating phosphorus oxychloride with methanol in the presence of an amine base:

POCl₃ 3 CH₃OH 3 R₃N → PO(OCH₃)₃ 3 R₃NHCl⁻

It is a tetrahedral molecule that is a weakly polar solvent.

Applications

Trimethyl phosphate is a mild methylating agent, useful for dimethylation of anilines and related heterocyclic compounds.^[2] The method is complementary to the traditional Eschweiler-Clarke reaction in cases where formaldehyde engages in side reactions.

Trimethyl phosphate is used as a solvent for aromatic halogenations and nitrations as required for the preparation of pesticides and pharmaceuticals.

Other applications

It is used as a color inhibitor for fibers (e.g. polyester) and other polymers. Trimethyl phosphate is used as a simulant for chemical weapon nerve agents.^{[citation needed]}

Safety considerations

With an LD50 of 2g/kg for rats, trimethylphosphate is expected to have low acute toxicity.^[3]

References

^ D. E. C. Corbridge "Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology" 5th Edition Elsevier: Amsterdam 1995. ISBN 0-444-89307-5.
^ William A. Sheppard (1973). "m-Trifluoromethyl-N,N-dimethylaniline". Organic Syntheses; Collected Volumes, vol. 5, p. 1085.
^ J. Svara, N. Weferling, T. Hofmann "Phosphorus Compounds, Organic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2006. doi:10.1002/14356007.a19_545.pub2

External links

WebBook page for C3H9PO4

[1] D. E. C. Corbridge "Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology" 5th Edition Elsevier: Amsterdam 1995. ISBN 0-444-89307-5.

[2] William A. Sheppard (1973). "m-Trifluoromethyl-N,N-dimethylaniline". Organic Syntheses; Collected Volumes, vol. 5, p. 1085.

[3] J. Svara, N. Weferling, T. Hofmann "Phosphorus Compounds, Organic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2006. doi:10.1002/14356007.a19_545.pub2

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