Trimethyl borate





































Trimethyl borate




Trimethyl-borate-2D.png


Trimethyl-borate-3D-vdW.png

Names
Other names
trimethoxyborane, boron trimethoxide

Identifiers

CAS Number



  • 121-43-7 ☑Y


3D model (JSmol)


  • Interactive image


ChEBI


  • CHEBI:38913 ☑Y


ChemSpider


  • 8157 ☑Y


ECHA InfoCard

100.004.063

EC Number
204-468-9


PubChem CID


  • 8470





Properties

Chemical formula


C3H9BO3

Molar mass
103.91 g·mol−1
Appearance
colourless liquid

Density
0.932 g/ml

Melting point
−34 °C (−29 °F; 239 K)

Boiling point
68 to 69 °C (154 to 156 °F; 341 to 342 K)

Solubility in water

decomposition
Hazards
Main hazards
flammable
Related compounds

Other cations


Trimethyl phosphite
Tetramethyl orthosilicate

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).


☑Y verify (what is ☑Y☒N ?)

Infobox references


Trimethyl borate is the organoboron compound with the formula B(OCH3)3. It is a colourless liquid that burns with a green flame.[1] It is an intermediate in the preparation of sodium borohydride and is a popular reagent in organic chemistry. It is a weak Lewis acid (AN = 23, Gutmann-Beckett method). [2]




Green fire of boric acid in methanol


Borate esters are prepared by heating boric acid or related boron oxides with alcohols under conditions where water is removed.[1]





Applications


Trimethyl borate is the main precursor to sodium borohydride by its reaction with sodium hydride:


4 NaH + B(OCH3)3 → NaBH4 + 3 NaOCH3

It is a gaseous anti-oxidant in brazing and solder flux. Otherwise, trimethyl borate has no announced commercial applications. It has been explored as a fire retardant, as well as being examined as an additive to some polymers.[1] It is a useful reagent in organic synthesis, as a precursor to boronic acids, which are used in Suzuki couplings. These boronic acids are prepared via reaction of the trimethyl borate with Grignard reagents followed by hydrolysis:.[3][4]


ArMgBr + B(OCH3)3 → MgBrOCH3 + ArB(OCH3)2

ArB(OCH3)2 + 2 H2O → ArB(OH)2 + 2 HOCH3




References



  1. ^ abc Robert J. Brotherton, C. Joseph Weber, Clarence R. Guibert, John L. Little "Boron Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2000, Wiley-VCH. doi:10.1002/14356007.a04_309


  2. ^ M.A. Beckett, G.C. Strickland, J.R. Holland, and K.S. Varma, "A convenient NMR method for the measurement of Lewis acidity at boron centres: correlation of reaction rates of Lewis acid initiated epoxide polymerizations with Lewis acidity", Polymer, 1996, 37, 4629–4631. doi: 10.1016/0032-3861(96)00323-0


  3. ^ Kazuaki Ishihara, Suguru Ohara, Hisashi Yamamoto (2002). "3,4,5-Trifluorophenylboronic Acid". Organic Syntheses. 79: 176.CS1 maint: Multiple names: authors list (link) .mw-parser-output cite.citationfont-style:inherit.mw-parser-output qquotes:"""""""'""'".mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:inherit;padding:inherit.mw-parser-output .cs1-lock-free abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-lock-subscription abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolor:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:help.mw-parser-output .cs1-hidden-errordisplay:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em; Collective Volume, 10, p. 80


  4. ^ R. L. Kidwell, M. Murphy, and S. D. Darling (1969). "Phenols: 6-Methoxy-2-naphthol". Organic Syntheses. 49: 90.CS1 maint: Multiple names: authors list (link) ; Collective Volume, 10, p. 80



External links


  • National Pollutant Inventory - Boron and compounds

  • MSDS for Trimethyl Borate

  • WebBook page for BC3H9O3


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