trimethyl phosphate
{{chembox
| Watchedfields = changed
| verifiedrevid = 470615226
| Name = Trimethyl phosphate
| ImageFile = Trimethyl-phosphate-3D-balls.png
| ImageName = Ball-and-stick model of trimethyl phosphate
| PIN = Trimethyl phosphate
| OtherNames = Phosphoric acid trimethyl ester
Methyl phosphate, tribasic
Trimethoxyphosphine oxide
Trimethyl orthophosphate fraction
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 512-56-1
| Abbreviations = TMP
| Beilstein = 1071731
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 46324
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 10101
| Gmelin = 49926
| PubChem = 10541
| RTECS = TC8225000
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = Z1E45TMW1Z
| SMILES = O=P(OC)(OC)OC
| InChI = 1/C3H9O4P/c1-5-8(4,6-2)7-3/h1-3H3
| InChIKey = WVLBCYQITXONBZ-UHFFFAOYAV
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C3H9O4P/c1-5-8(4,6-2)7-3/h1-3H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = WVLBCYQITXONBZ-UHFFFAOYSA-N
}}
|Section2={{Chembox Properties
| Formula = (CH3O)3PO
| MolarMass = 140.08
| Appearance = Colorless liquid
| Solubility = good
| MeltingPtC = -46
| BoilingPtC = 197
}}
|Section7={{Chembox Hazards
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| GHSPictograms = {{GHS05}}{{GHS07}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|315|318|319|340|350|351|361|373}}
| PPhrases = {{P-phrases|201|202|260|264|270|280|281|301+312|302+352|305+351+338|308+313|310|314|321|330|332+313|337+313|362|405|501}}
}}
}}
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.D. E. C. Corbridge "Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology" 5th Edition Elsevier: Amsterdam 1995. {{ISBN|0-444-89307-5}}.
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 R3NH+Cl−
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.{{OrgSynth
| author =William A. Sheppard
| year =1973
| title =m-Trifluoromethyl-N,N-dimethylaniline
| volume =
| pages =
| collvol =5
| collvolpages =1085
| prep =CV5P1085}} 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|date=September 2021}}
Safety considerations
With an LD50 of 2g/kg for rats, trimethylphosphate is expected to have low acute toxicity.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}}
References
{{Reflist}}
External links
- [http://webbook.nist.gov/cgi/cbook.cgi?ID=C512561 WebBook page for C3H9PO4]