triethyl orthoformate

{{chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 421482767

| ImageFile = Triethoxymethane.svg

| ImageSize = 180px

| ImageAlt = Structural formula

| ImageFile1 = Triethyl-orthoformate-3D-balls.png

| ImageSize1 = 180

| ImageAlt1 = Ball-and-stick model

| PIN=(Diethoxymethoxy)ethane

| OtherNames=Triethoxymethane; Ethyl orthoformate

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo=122-51-0

| PubChem=31214

| EC_number = 204-550-4

| UNNumber = 2524

| UNII = 355LRR361Q

| ChEMBL = 1476236

| SMILES=CCOC(OCC)OCC

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| ChemSpiderID = 28955

| InChI = 1/C7H16O3/c1-4-8-7(9-5-2)10-6-3/h7H,4-6H2,1-3H3

| InChIKey = GKASDNZWUGIAMG-UHFFFAOYAW

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

| StdInChI = 1S/C7H16O3/c1-4-8-7(9-5-2)10-6-3/h7H,4-6H2,1-3H3

| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = GKASDNZWUGIAMG-UHFFFAOYSA-N

}}

|Section2={{Chembox Properties

| C=7 | H=16 | O=3

| Appearance=

| Density=0.891 g/mL

| MeltingPtC= -76

| BoilingPtC= 146

| Solubility=

}}

|Section3={{Chembox Hazards

| GHSPictograms = {{GHS02}}{{GHS07}}

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|226|315|319|335}}

| PPhrases = {{P-phrases|210|233|240|241|242|243|261|264|271|280|302+352|303+361+353|304+340|305+351+338|312|321|332+313|337+313|362|370+378|403+233|403+235|405|501}}

| ExternalSDS = [https://fscimage.fishersci.com/msds/97204.htm Fischer Scientific]

| FlashPt=

| AutoignitionPt =

}}

}}

Triethyl orthoformate is an organic compound with the formula HC(OC2H5)3. This colorless volatile liquid, the ortho ester of formic acid, is commercially available. The industrial synthesis is from hydrogen cyanide and ethanol.Ashford's Dictionary of Industrial Chemicals, Third edition, 2011, page 9288

It may also be prepared from the reaction of sodium ethoxide, formed in-situ from sodium and absolute ethanol, and chloroform:{{OrgSynth | title = Ethyl orthoformate | author = W. E. Kaufmann and E. E. Dreger | prep = CV1P0258 | collvol =1 | collvolpages = 258 | year = 1941}}

: CHCl3 + 3 Na + 3 EtOH → HC(OEt)3 + {{frac|3|2}} H2 + 3 NaCl

Triethyl orthoformate is used in the Bodroux–Chichibabin aldehyde synthesis, for example:{{OrgSynth | title = n-Hexaldehyde | author = G. Bryant Bachman | collvol = 2 | collvolpages = 323 | year = 1943 | prep = CV2P0323}}

: RMgBr + HC(OC2H5)3 → RC(H)(OC2H5)2 + MgBr(OC2H5)

: RC(H)(OC2H5)2 + H2O → RCHO + 2 C2H5OH

In coordination chemistry, it is used to convert metal aquo complexes to the corresponding ethanol complexes:Willem L. Driessen, Jan Reedijk "Solid Solvates: The Use of Weak Ligands in Coordination Chemistry" Inorg. Synth., 1992, Vol. 29,111–118. {{doi|10.1002/9780470132609.ch27}}

:[Ni(H2O)6](BF4)2 + 6 HC(OC2H5)3 → [Ni(C2H5OH)6](BF4)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.

See also

References