Triethyl orthoformate is an
organic compound with the formula HC(OC
2H
5)
3. This colorless volatile liquid, the
orthoester of
formic acid
Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Es ...
, is commercially available. The industrial synthesis is from hydrogen cyanide and ethanol.
It may also be prepared from the reaction of
sodium ethoxide, formed
in-situ from
sodium and absolute
ethanol, and
chloroform
Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to ...
:
: CHCl
3 + 3 Na + 3 EtOH → HC(OEt)
3 + H
2 + 3 NaCl
Triethyl orthoformate is used in the
Bodroux-Chichibabin aldehyde synthesis, for example:
: RMgBr + HC(OC
2H
5)
3 → RC(H)(OC
2H
5)
2 + MgBr(OC
2H
5)
: RC(H)(OC
2H
5)
2 + H2O → RCHO + 2 C
2H
5OH
In
coordination chemistry
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...
, it is used to convert
metal aquo complexes to the corresponding ethanol complexes:
:
i(H2O)6BF
4)
2 + 6 HC(OC
2H
5)
3 →
i(C2H5OH)6BF
4)
2 + 6 HC(O)(OC
2H
5) + 6 HOC
2H
5
Triethyl orthoformate (TEOF) is an excellent reagent for converting compatible carboxylic acids to ethyl esters. Such carboxylic acids, refluxed neat in excess TEOF until low-boilers cease evolution, are quantitatively converted to the ethyl esters, without need for extraneous catalysis.
[{{Cite journal, last=Paine, first=John B., date=July 2008, title=Esters of Pyromellitic Acid. Part I. Esters of Achiral Alcohols: Regioselective Synthesis of Partial and Mixed Pyromellitate Esters, Mechanism of Transesterification in the Quantitative Esterification of the Pyromellitate System Using Orthoformate Esters, and a Facile Synthesis of the Ortho Pyromellitate Diester Substitution Pattern, url=http://dx.doi.org/10.1021/jo800543w, journal=The Journal of Organic Chemistry, volume=73, issue=13, pages=4929–4938, doi=10.1021/jo800543w, pmid=18522420 , issn=0022-3263] Alternatively, added to ordinary esterifications using catalytic acid and ethanol, TEOF helps drive esterification to completion by converting the byproduct water formed to ethanol and ethyl formate.
See also
*
Trimethyl orthoformate
References
Orthoesters
Ethyl esters