Trimethyl borate is the

organoboron compound Organoborane or organoboron compounds are chemical compounds of boron and carbon that are organic derivatives of BH3, for example trialkyl boranes. Organoboron chemistry or organoborane chemistry is the chemistry of these compounds. Organoboron ...

with the formula B(OCH₃)₃. It is a colourless liquid that burns with a green flame. It is an intermediate in the preparation of

sodium borohydride Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula Na BH4. This white solid, usually encountered as an aqueous basic solution, is a reducing agent that finds appli ...

and is a popular

reagent In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...

in organic chemistry. It is a weak Lewis acid (AN = 23, Gutmann-Beckett method). 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 Boratflamme

Borate ester In organic chemistry, borate esters are organoboron compounds which are conveniently prepared by the stoichiometric condensation reaction of boric acid with alcohols. There are two main classes of borate esters: orthoborates, and metaborates, . ...

s are prepared by heating

boric acid Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula . It may also be called hydrogen borate or boracic acid. It is usually encountered as colorless crystals or a white powder, that dissolves ...

or related boron oxides with alcohols under conditions where water is removed.

Applications

Trimethyl borate is the main precursor to

by its reaction with

sodium hydride Sodium hydride is the chemical compound with the empirical formula Na H. This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis. NaH is a saline (salt-like) hydride, composed of Na+ and H− ions, in co ...

: :4 NaH + B(OCH₃)₃ → NaBH₄ + 3 NaOCH₃ It is a gaseous anti-oxidant in

brazing Brazing is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, with the filler metal having a lower melting point than the adjoining metal. Brazing differs from we ...

and

solder Solder (; NA: ) is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable ...

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.

Organic synthesis

It is a useful reagent in organic synthesis, as a precursor to

boronic acid A boronic acid is an organic compound related to boric acid () in which one of the three hydroxyl groups () is replaced by an alkyl or aryl group (represented by R in the general formula ). As a compound containing a carbon–boron bond, membe ...

s, which are used in Suzuki couplings. These boronic acids are prepared via reaction of the trimethyl borate with

Grignard reagent A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide ...

s followed by hydrolysis:.{{OrgSynth, author=R. L. Kidwell, M. Murphy, and S. D. Darling, year=1969, title=Phenols: 6-Methoxy-2-naphthol , volume=49, pages=90, collvol=10, collvolpages=80, prep=CV5P0918 : ArMgBr + B(OCH₃)₃ → MgBrOCH₃ + ArB(OCH₃)₂ :ArB(OCH₃)₂ + 2 H₂O → ArB(OH)₂ + 2 HOCH₃

References

External links

National Pollutant Inventory - Boron and compoundsMSDS for Trimethyl BorateWebBook page for BC₃H₉O₃
Methyl esters Borate esters Solvents