Steglich esterification

{{short description|Chemical reaction}}

{{Reactionbox

| Name = Steglich esterification

| Type = Coupling reaction

| NamedAfter = Wolfgang Steglich

| Section3 = {{Reactionbox Identifiers

| OrganicChemistryNamed = steglich-esterification

}}

}}

The Steglich esterification is a variation of an esterification with dicyclohexylcarbodiimide as a coupling reagent and 4-dimethylaminopyridine as a catalyst. The reaction was first described by Wolfgang Steglich in 1978.{{cite journal | author = B. Neises, W. Steglich | title = Simple Method for the Esterification of Carboxylic Acids | journal = Angew. Chem. Int. Ed. | year = 1978 | volume = 17 | pages = 522–524 | doi = 10.1002/anie.197805221 | issue = 7}} It is an adaptation of an older method for the formation of amides by means of DCC (dicyclohexylcarbodiimide) and 1-hydroxybenzotriazole (HOBT).{{cite journal | author = J. C. Sheehan, G. P. Hess | title = A New Method of Forming Peptide Bonds | journal = J. Am. Chem. Soc. | year = 1955 | volume = 77 | pages = 1067–1068 | doi = 10.1021/ja01609a099 | issue = 4}}{{cite journal | author = W. König, R. Geiger | title = Eine neue Methode zur Synthese von Peptiden: Aktivierung der Carboxylgruppe mit Dicyclohexylcarbodiimid unter Zusatz von 1-Hydroxy-benzotriazolen | journal = Chem. Ber. | year = 1970 | volume = 103 | pages = 788–798 | doi = 10.1002/cber.19701030319 | issue = 3| pmid = 5436656 }}

:File:SteglichVeresterung Uebersicht.svg

This reaction generally takes place at room temperature. A variety of polar aprotic solvents can be used.{{cite journal |doi= 10.1039/D1GC02251B |journal= Green Chem. |year= 2021 |volume= 23 |pages= 6405–6413 |title= A solvent-reagent selection guide for Steglich-type esterification of carboxylic acids |first1= Andrew |last1= Jordan |first2= Kyran D. |last2= Whymark |first3 =Jack |last3= Sydenham |first4= Helen F. |last4= Sneddon |issue= 17 |doi-access= free }} Because the reaction is mild, esters can be obtained that are inaccessible through other methods for instance esters of the sensitive 2,4-dihydroxybenzoic acid. A characteristic is the formal uptake of water generated in the reaction by DCC, forming the urea compound dicyclohexylurea (DCU).