Triethyl orthoformate is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the formula HC(OC₂H₅)₃. This colorless volatile liquid, the

ortho ester In organic chemistry, an ortho ester is a functional group containing three alkoxy groups attached to one carbon atom, i.e. with the general formula . Orthoesters may be considered as products of exhaustive alkylation of unstable orthocarboxylic ...

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid. It has the chemical formula HCOOH and structure . This acid is an important intermediate in chemical synthesis and occurs naturally, most notably in some an ...

, is commercially available. The industrial synthesis is from hydrogen cyanide and ethanol. It may also be prepared from the reaction of

sodium ethoxide Sodium ethoxide, also referred to as sodium ethanolate, is the Ionic compound, ionic, organic compound with the formula , , or NaOEt (Et = ethyl group, ethyl). It is a white solid, although impure samples appear yellow or brown. It dissolves in p ...

, formed

in-situ is a Latin phrase meaning 'in place' or 'on site', derived from ' ('in') and ' ( ablative of ''situs'', ). The term typically refers to the examination or occurrence of a process within its original context, without relocation. The term is use ...

from

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

and absolute

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

, and

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

: : CHCl₃ + 3 Na + 3 EtOH → HC(OEt)₃ + H₂ + 3 NaCl Triethyl orthoformate is used in the

Bodroux–Chichibabin aldehyde synthesis The Bodroux–Chichibabin aldehyde synthesis is a chemical reaction whereby a Grignard reagent is converted to an aldehyde one carbon longer. : Reaction of a Grignard reagent with triethyl orthoformate gives an acetal, which can be hydrolyzed ...

, for example: : RMgBr + HC(OC₂H₅)₃ → RC(H)(OC₂H₅)₂ + MgBr(OC₂H₅) : RC(H)(OC₂H₅)₂ + H2O → RCHO + 2 C₂H₅OH In

coordination chemistry A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' ...

, it is used to convert

metal aquo complex In chemistry, metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlo ...

es to the corresponding ethanol complexes: : i(H₂O)₆BF₄)₂ + 6 HC(OC₂H₅)₃ → i(C₂H₅OH)₆BF₄)₂ + 6 HC(O)(OC₂H₅) + 6 HOC₂H₅ 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, url-access=subscription 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.

References

Orthoesters Ethyl esters

See also

References