Ethyl acetoacetate: Difference between revisions

|Watchedfields = changed

|verifiedrevid = 415312046

|Name = Ethyl acetoacetate

|ImageFile = Ethyl-acetoacetate-2D-skeletal.svg

|ImageAlt = Skeletal formula of ethyl acetoacetate

|ImageFile1 = Ethyl acetoacetate 3D spacefill.png

|ImageAlt1 = Space-filling model of the ethyl acetoacetate molecule

|PIN = Ethyl 3-oxobutanoate

|OtherNames = {{ubl|Acetoacetic acid ethyl ester|Ethyl acetylacetate|3-Oxobutanoic acid ethyl ester}}

|Section1={{Chembox Identifiers

|SMILES = CCOC(=O)CC(=O)C

|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

|ChemSpiderID = 13865426

|UNII_Ref = {{fdacite|correct|FDA}}

|UNII = IZP61H3TB1

|KEGG_Ref = {{keggcite|correct|kegg}}

|KEGG = C03500

|PubChem = 8868

|ChEBI = 4893

|EC_number = 205-516-1

|UNNumber = 1993

|InChI = 1/C6H10O3/c1-3-9-6(8)4-5(2)7/h3-4H2,1-2H3

|InChIKey = XYIBRDXRRQCHLP-UHFFFAOYAP

|ChEMBL_Ref = {{ebicite|correct|EBI}}

|ChEMBL = 169176

|StdInChI_Ref = {{stdinchicite|correct|chemspider}}

|StdInChI = 1S/C6H10O3/c1-3-9-6(8)4-5(2)7/h3-4H2,1-2H3

|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

|StdInChIKey = XYIBRDXRRQCHLP-UHFFFAOYSA-N

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

|CASNo = 141-97-9

|RTECS = AK5250000

}}

|Section2={{Chembox Properties

|Formula = C₆H₁₀O₃

|MolarMass = 130.14 g/mol

|Appearance = Colourless liquid

|Odour = [[Fruit]] or [[rum]]

|Density = 1.021 g/cm³, liquid

|Solubility = 2.86{{nbsp}}g/100{{nbsp}}ml (20{{nbsp}}°C)

|MeltingPtC = −45

|BoilingPtC = 180.8

|pKa = {{ubl|10.68 (in H₂O)|14.2 (in [[dimethyl sulfoxide|DMSO]])}}

|MagSus = −71.67×10⁻⁶cm³/mol

}}

|Section7={{Chembox Hazards

| GHSPictograms = {{GHS07}}

| GHSSignalWord = warning

| HPhrases = {{HPhrases|H319}}

| PPhrases = {{PPhrases|P305+P351+P338}}

| GHS_ref = <ref>{{GESTIS|ZVG=10400|Date=2021-12-19}}</ref>

|NFPA-H = 2

|NFPA-F = 2

|NFPA-R =

|FlashPtC = 70

}}

|Section8={{Chembox Related

|OtherFunction_label = [[ester]]s

|OtherFunction = {{ubl|[[Methyl acetoacetate]]|[[Ethyl acetate]]|[[Diethyl malonate]]}}

|OtherCompounds = {{ubl|[[Acetone]]|[[Acetylacetone]]|[[Diketene]]}}

}}

The [[organic compound]] '''ethyl acetoacetate''' ('''EAA''') is the [[ethyl group|ethyl]] [[ester]] of [[acetoacetic acid]]. It is a colorless liquid. It is widely used as a [[chemical intermediate]] in the production of a wide variety of compounds.

At large scale, ethyl acetoacetate is industrially produced by treatment of [[diketene]] with [[ethanol]].<ref>{{cite book|doi=10.1002/14356007.a09_565.pub2|chapter=Esters, Organic|year=2005|last1=Riemenschneider|first1=Wilhelm|last2=Bolt|first2=Hermann M.|isbn=3527306730|title=Ullmann's Encyclopedia of Industrial Chemistry|location=Weinheim|publisher=Wiley-VCH}}</ref>

The small scale preparation of ethyl acetoacetate is a classic laboratory procedure.<ref>{{OrgSynth | author = J. K. H. Inglis and K. C. Roberts | title = Ethyl Acetoacetate | volume = 6 | pages = 36 | doi = 10.15227/orgsyn.006.0036 | year = 1926}}</ref> It involves [[Claisen condensation]] of [[ethyl acetate]]. Two moles of ethyl acetate condense to form one mole each of ethyl acetoacetate and ethanol.

:[[File:Claisen ethyl acetate.png|400px|left|Preparation of ethyl acetoacetate]]{{clear|left}}

Ethyl acetoacetate is subject to [[keto-enol tautomerism]]. In the neat liquid at 33&nbsp;°C, the enol consists of 15% of the total.<ref>{{cite journal|title=Keto-Enol Tautomerism in β-Dicarbonyls Studied by Nuclear Magnetic Resonance Spectroscopy. I. Proton Chemical Shifts and Equilibrium Constants of Pure Compounds|author1=Jane L. Burdett|author2=Max T. Rogers|journal=J. Am. Chem. Soc.|year=1964|volume=86|pages=2105–2109|doi=10.1021/ja01065a003}}</ref> The enol is moderately acidic. Thus ethyl acetoacetate behaves similarly to [[acetylacetone]]:<ref name=RmC/>

:CH₃C(O)CH₂CO₂Et + NaH → CH₃C(O)CH(Na)CO₂Et + H₂

The resulting carbanion undergoes [[nucleophilic substitution]]. Ethyl acetoacetate is often used in the [[acetoacetic ester synthesis]], comparable to [[diethyl malonate]] in the [[malonic ester synthesis]] or the [[Knoevenagel condensation]]. After its alkylation and saponification, [[thermal decarboxylation]] is also possible.<ref>{{cite book | first=Francis A. | last=Carey | year=2006 | title=Organic Chemistry | edition=Sixth | publisher=McGraw-Hill | location=New York, NY | isbn=0-07-111562-5}}</ref> Like acetylacetone, ethyl acetoacetate affords ketoenolate complexes<ref>{{cite journal |doi=10.1107/S010827010001249X}}</ref>

The dianion of ethylacetoacetate is also a useful building block, except that the electrophile adds to the terminal carbon. The strategy can be depicted in the following simplified form:<ref name=RmC>{{cite journal |doi=10.15227/orgsyn.084.0043|title=Stereoselective Isoprenoid Chain Extension with Acetoacetate Dianion: [(''E, E, E'')-Geranylgeraniol from (''E, E'')-Farnesol|journal=Organic Syntheses|year=2007|volume=84|page=43|first1=Yinghua|last1=Jin|first2=Frank G.|last2=Roberts|first3=Robert M.|last3=Coates}}</ref>

:CH₃C(O)CH(Na)CO₂Et + BuLi → LiCH₂C(O)CH(Na)CO₂Et + BuH

:LiCH₂C(O)CH(Na)CO₂Et + RX → RCH₂C(O)CH(Na)CO₂Et + LiX

Reduction of ethyl acetoacetate gives ethyl 3-hydroxybutyrate.<ref>{{cite journal |doi=10.1021/ja01375a082}}</ref>

Ethyl acetoacetate transesterifies to give benzyl acetoacetate via a mechanism involving acetylketene. Ethyl (and other) acetoacetates nitrosate readily with equimolar sodium nitrite in acetic acid, to afford the corresponding oximinoacetoacetate esters. A dissolving-zinc reduction of these in acetic acid in the presence of ketoesters or beta-diketones constitute the [[Knorr pyrrole synthesis]], useful for the preparation of [[porphyrin]]s.

==See also==

Two ketals of ethyl acetoacetate are used in commercial fragrances.<ref>{{cite book |doi=10.1002/14356007.t11_t02 |chapter=Flavors and Fragrances, 3. Aromatic and Heterocyclic Compounds |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2016 |last1=Panten |first1=Johannes |last2=Surburg |first2=Horst |pages=1–45 |isbn=978-3-527-30673-2 }}</ref>

* [[Fructone]] ({{chem2|CH3C(O2C2H4)CH2CO2C2H5}}), the ethylene glycol ketal

* Fraistone ({{chem2|CH3C(O2C2H3CH3)CH2CO2C2H5}}), the propylene glycol ketal

{{Reflist}}

*[http://www.inchem.org/documents/icsc/icsc/eics1024.htm International Chemical Safety Card 1024]

*[http://www.inchem.org/documents/icsc/icsc/eics1024.htm Inchem properties database]

{{Authority control}}

[[Category:Acetoacetate esters]]

[[Category:Sweet-smelling chemicals]]