Triethyl orthoformate
Triethyl orthoformate is an organic compound with the formula HC3. It is a colorless volatile liquid. It is orthoester of formic acid. It is commercially available. The industrial synthesis is from hydrogen cyanide and ethanol.
It may also be prepared from the reaction of sodium ethoxide and chloroform:
Triethyl orthoformate is used in the Bodroux-Chichibabin aldehyde synthesis, for example:
In coordination chemistry, it is used to convert metal aquo complexes to the corresponding ethanol complexes:
Triethyl orthoformate 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. Ref. J.B.Paine III, J. Org. Chem. 2008, 73, 4929-4938. 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.
