Ethyl ester

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Ethyl ester of a carboxylic acid. The ethyl ester residue is marked in blue . R stands for a hydrogen atom or an organyl radical (alkyl radical, aryl radical or alkylaryl radical, etc.). In chloroformate
ester R is a chlorine atom.
Diethyl ester (top) and monoethyl ester (bottom) of carbonic acid. The functional group is marked in blue .
Ethyl ester of a sulfonic acid. The ethyl ester residue is marked in blue . R stands for an organyl radical (alkyl radical, aryl radical or alkylaryl radical, etc.).

Ethyl esters are chemical compounds that belong to the group of carboxylic acid esters . They are created by esterifying a carboxylic acid with ethanol . They have the characteristic functional ester group . In a broader sense, the ethyl esters also include carbonic acid esters and esters derived from sulfonic acids and ethanol. Similarly, ethyl esters in the broader sense can also form from nitric acid , sulfinic acids , phosphonic acids or phosphinic acids on the one hand and ethanol on the other. Triethyl orthoformate , HC (OC 2 H 5 ) 3 , is a well-known representative of the orthocarboxylic acid ester .

Occurrence

Carboxylic acid ethyl esters come as so. Fruit esters are found in many fruits and dishes as an odor-giving component. In nature, butyric acid ethyl ester occurs in various plants, e.g. B. in strawberries, apples, oranges and pineapples. ( Z ) - 4-Decenoic acid ethyl ester , ( E ) - 2-octenoic acid ethyl ester and ( E, Z ) - 2,4-decadienoic acid ethyl ester are found in pears, ( S ) - 2-methylbutyric acid ethyl ester in orange and pineapple. Ethyl formate is a component of rum and arrack .

Manufacturing

Ethyl esters arise z. B. from a carboxylic acid and ethanol with acid-catalyzed dehydration.

Production of ethyl acetate from ethanol and acetic acid

Ethyl esters can also be obtained from carboxylic acid chlorides and ethanol by the Schotten-Baumann method . Ethyl esters can also be synthesized from carboxylic acid anhydrides and ethanol . The nucleophilic substitution of methyl halides (e.g. ethyl iodide ) with carboxylate ions also yields ethyl esters.

Similarly, diethyl esters are formed from dicarboxylic acids and ethanol, triethyl esters from tricarboxylic acids and ethanol, etc.

use

Ethyl acetate is used as a solvent and gelatinizing agent - e.g. B. for collodion wool and celluloid - used in industry. Some ethyl esters of carboxylic acids are used as flavorings and flavorings.

Due to their increased lipophilicity, ethyl esters can pass barriers or bypass amino acid transport defects. Ethyl esters of L-tryptophan and possibly other amino acids are the only treatment option for severe cases of Hartnup's disease.

See also

Individual evidence

  1. ^ Siegfried Hauptmann : Organic Chemistry , 2nd revised edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig 1985, ISBN 3-342-00280-8 , p. 421.
  2. ↑ Wolfgang Legrum: Fragrances, between stink and fragrance , Vieweg + Teubner Verlag (2011), ISBN 978-3-8348-1245-2 , pp. 85–86.
  3. ^ AJ Jonas, IJ Butler: Circumvention of defective neutral amino acid transport in Hartnup disease using tryptophan ethyl ester. In: The Journal of clinical investigation. Volume 84, Number 1, July 1989, pp. 200-204, ISSN  0021-9738 . doi : 10.1172 / JCI114141 . PMID 2472426 . PMC 303970 (free full text).