{{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 <!-- Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) --> | OtherNames = Phosphoric acid trimethyl ester<br />Methyl phosphate, tribasic<br />Trimethoxyphosphine oxide<br />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 = {{chem2|(CH3O)3PO}} | C=3|H=9|P=1|O=4 | 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}} }} | Section9={{Chembox Related | OtherCompounds = Triethyl phosphate }} }}
'''Trimethyl phosphate''' is the trimethyl ester of phosphoric acid. It is a colourless, nonvolatile liquid. It has the chemical formula {{chem2|(CH3)3PO4}} or {{chem2|(CH3O)3P\dO}}. It has some specialized uses in the production of other compounds.<ref>D. E. C. Corbridge "Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology" 5th Edition Elsevier: Amsterdam 1995. {{ISBN|0-444-89307-5}}.</ref>
==Production== Trimethyl phosphate is prepared by treating phosphorus oxychloride with methanol in the presence of an amine base: :{{chem2|POCl3 + 3 CH3OH + 3 R3N → OP(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.<ref>{{OrgSynth | author =William A. Sheppard | year =1973 | title =m-Trifluoromethyl-N,N-dimethylaniline | volume = | pages = | collvol =5 | collvolpages =1085 | prep =CV5P1085}} </ref> 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=== <!--totally mysterious--> 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.<ref>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}}</ref>
==References== {{Reflist}}
==External links== *[https://webbook.nist.gov/cgi/cbook.cgi?ID=C512561 WebBook page for C3H9PO4]
Category:Organophosphates Category:Ester solvents Category:Methyl esters Category:Methylating agents