Ethyl acetate 1303134 224505881 2008-07-09T04:03:23Z 165.123.209.127 /* Preparation */ {{Chembox new | Name = Ethyl acetate | ImageFile = Ethyl-acetate-2D-skeletal.png <!-- | ImageSize = 150px --> | ImageName = Ethyl acetate | ImageFile1 = Ethyl-acetate-3D-balls.png <!-- | ImageSize1 = 150px --> | ImageName1 = Ethyl acetate | IUPACName = Ethyl ethanoate | OtherNames = ethyl ester,</br> acetic ester,</br> ester of ethanol</br> | Section1 = {{Chembox Identifiers | SMILES = CCOC(C)=O | CASNo = 141-78-6 | RTECS = AH5425000 }} | Section2 = {{Chembox Properties | Formula = C<sub>4</sub>H<sub>8</sub>O<sub>2</sub> | MolarMass = 88.105 g/mol | Appearance = colorless liquid | Density = 0.897 g/cm³, liquid | Solubility = 8.3 g/100 mL (20 °C) | Solvent = [[ethanol]],</br> [[acetone]], [[diethyl ether]],</br> [[benzene]] | SolubleOther = Miscible | MeltingPt = −83.6 °C (189.55 K) | BoilingPt = 77.1 °C (350.25 K) | Viscosity = 0.426 [[Poise|cP]] at 25 °C | RefractIndex = 1.3720 }} | Section3 = {{Chembox Structure | Dipole = 1.78 [[Debye|D]] }} | Section7 = {{Chembox Hazards | ExternalMSDS = | MainHazards = Flammable (F),<br />Irritant (Xi) | NFPA-H = 1 | NFPA-F = 3 | NFPA-R = | RPhrases = {{R11}}, {{R36}}, {{R66}}, {{R67}} | SPhrases = {{S16}}, {{S26}}, {{S33}} | FlashPt = −4 °C }} | Section8 = {{Chembox Related | Function = [[carboxylate ester]]s | OtherFunctn = [[Methyl acetate]],<br />[[Propyl acetate]],<br />[[Butyl acetate]] | OtherCpds = [[Acetic acid]],<br />[[ethanol]] }} }} '''Ethyl acetate''' ([[IUPAC nomenclature of organic chemistry|systematically]], ethyl ethanoate, commonly abbreviated EtOAc or EA) is the [[organic compound]] with the formula CH<sub>3</sub>COOCH<sub>2</sub>CH<sub>3</sub>. This colorless liquid has a characteristic, not unpleasant smell (similar to [[pear drops]]) like certain [[glue]]s or [[nail polish remover]]s, in which it is used. Ethyl acetate is the [[ester]] from [[ethanol]] and [[acetic acid]]; it is manufactured on a large scale for use as a solvent. ==Properties== Ethyl acetate is a moderately polar solvent that has the advantages of being [[Volatility (chemistry)|volatile]], relatively non-toxic, and non-[[hygroscopic]]. It is a weak [[hydrogen bond]] acceptor, and is not a donor due to the lack of an [[acidic]] proton (one directly bonded to an [[electronegative]] atom such as fluorine, oxygen, or nitrogen). Ethyl acetate can dissolve up to 3% [[water]] and has a [[solubility]] of 8% in water at room temperature. At elevated temperature its [[solubility]] in water is higher. It is unstable in the presence of strong aqueous [[Base (chemistry)|bases]] and [[acid]]s. ==Preparation== Ethyl acetate is synthesized via the [[Fischer esterification]] reaction from [[ethanol]] and [[acetic acid]], typically in the presence of an acid catalyst such as concentrated [[sulfuric acid]]. :CH<sub>3</sub>CH<sub>2</sub>OH + CH<sub>3</sub>COOH → CH<sub>3</sub>COOCH<sub>2</sub>CH<sub>3</sub> + [[Water (molecule)|H<sub>2</sub>O]] It can also be prepared through [[Tishchenko reaction]], by combining two equivalents of [[acetaldehyde]] in the presence of an [[alkoxide]] base as catalyst. This way is a commercial method of producing ethyl acetate.{{Fact|date=May 2008}} :CH<sub>3</sub>CHO + CH<sub>3</sub>CHO → CH<sub>3</sub>COOC<sub>2</sub>H<sub>5</sub> ==Industrial production== Industrially, ethyl acetate can be produced by the catalytic [[dehydrogenation]] of [[ethanol]]. For cost reasons, this method is primarily applied to conversion of surplus ethanol feedstock as opposed to predetermined generation on an industrial scale. In addition, it is commonly accepted as far less practical and less cost effective. Catalysts for dehydrogenation include copper, operating at an elevated temperature but below 250 °C. The copper may have its surface area increased by depositing it on zinc, promoting the growth of snowflake, fractal like, structures. This surface area can be again increased by deposition onto a [[zeolite]], typically ZSM-5. Traces of rare earth metals or alkalies, such as that of sodium and potassium, have also been found to be beneficial to the process. Byproducts of hydrogenation include [[diethyl ether]] (thought to primarily arise due to aluminum sites in the catalyst), acetaldehyde, acetaldehyde aldol products, higher esters and ketones. [[Acetaldehyde]] and [[MEK]] complicate conversion and purification as ethanol forms an [[azeotrope]] with water, as does ethyl acetate with ethanol and water and MEK with both ethanol and the acetate. To obtain a high purity product, these azeotropes must be "broken", and this can be achieved by making use of pressure swing distillation. The composition of the distillate removed from the conversion products is biased towards acetate at atmospheric pressure and ethanol at increased pressure. First, the raw product is fed into a high pressure column where the bulk of the contaminating ethanol is removed. By then feeding the ethanol depleted distillate into a low pressure column, the acetate can be removed from the remaining ethanol azeotrope. MEK forms during the conversion process from 2-butanol. The latter fails to form an azeotrope with the acetate and so MEK can be removed by hydrogenation of the contaminated product over nickel and further distillation to strip away 2-butanol. This provides the simultaneous benefit of removing the acetylaldehyde contaminant by returning it to an ethanol form and is easily accomplished as hydrogen is a byproduct of the initial dehydrogenation process. It may also be possible to break the azeotropes with the use of membrane distillation, molecular sieves, an entrainer or absorption medium. The distilled ethanol and rehydrogenated contaminants can then be recycled into the raw feedstock. ==Uses== ===Solvent=== Ethyl acetate is primarily used as a [[solvent]]. For example, it is commonly used to dissolve the pigments for [[nail varnish]]es, and is responsible for the solvent-effect of some nail varnish remover ([[acetone]] and [[acetonitrile]] are also used). Industrially it is used to [[decaffeinate]] coffee beans and tea leaves.{{Fact|date=April 2007}} It is also used in paints as an activator or hardener.{{Fact|date=December 2007}} In the laboratory, a mixture of ethyl acetate and hexane is the most common solvent system used as a [[chromatography]] solvent. It is also used as a solvent for [[liquid-liquid extraction|extractions]]. It is rarely used as a reaction mixture because it is prone to [[hydrolysis]]. Like most simple esters, ethyl acetate has a fruity smell. Ethyl acetate is present in confectionery, perfumes, and fruits. In perfumes, it evaporates quickly, leaving but the scent of the perfume on the skin. ===Occurrence in wines=== Ethyl acetate is present in wines. It may be considered a contaminant at too high concentrations, as typically occurs when wine is exposed to air for a prolonged period. When present at too high concentration in [[wine]], it is regarded as an off-flavor. ===Other uses=== In the field of [[entomology]], ethyl acetate is an effective poison for use in [[insect collecting]] and study. In a [[killing jar]] charged with ethyl acetate, the vapors will kill the collected (usually adult) insect quickly without destroying it. Because it is not [[hygroscopic]], ethyl acetate also keeps the insect soft enough to allow proper mounting suitable for a collection. ==Reactions== Ethyl acetate can be [[hydrolyzed]] in acid or basic conditions to regain acetic acid and ethanol. The use of an acid catalyst such as [[sulfuric acid]] gives poor yields due to it being an equilibrium &mdash; the reverse reaction of the Fischer esterification. To obtain high yields, it is preferable to use a stoichiometric amount of strong base, such as [[sodium hydroxide]]. This reaction gives ethanol and [[sodium acetate]], which is not able to react with ethanol any longer: :CH<sub>3</sub>CO<sub>2</sub>C<sub>2</sub>H<sub>5</sub> + NaOH → C<sub>2</sub>H<sub>5</sub>OH + CH<sub>3</sub>CO<sub>2</sub>Na ==References== {{citationstyle|date=September 2007}} <references/> * ''Chembytes e-zine - Team effort: Steve Colley describes work to develop a new route to make ethyl acetate starting from low grade renewable feedstocks'' (2001)[http://www.chemsoc.org/chembytes/ezine/2001/colley_aug01.htm#] * ''Ingenia Online - Renewable Processing: The Green Alternative; Using Bio-Ethanol To Manufacture An Industrial Solvent by Mike Ashley'' (Issue 29, 2006)[http://www.ingenia.org.uk/ingenia/articles.aspx?index=403&print=true] Some industrial plants use Ethylene----> Acetic Acid in the presence of an tungstasilic acid on a silica support. This is the catalyst and the Exothermic reaction is cooled by water/ethanol/acetic acid. ==External links== * [http://www.jtbaker.com/msds/englishhtml/e2850.htm Material safety data (MSDS)] for ethyl acetate * [http://www.npi.gov.au/database/substance-info/profiles/38.html National Pollutant Inventory - Ethyl acetate fact sheet] * [http://www.chm.bris.ac.uk/motm/ethylacetate/ethylh.htm Ethyl Acetate: Molecule of the Month] * [http://hsc.csu.edu.au/chemistry/core/acidic/chem935/chem935net.html#net4 Purpose of Using Concentrated Sulfuric Acid in Esterification for Catalysis] * [http://www.sekab.com/Eng/Informationssidor/Produktblad/Microsoft%20Word%20-%20New%20Ethyl%20acetate.DOC.165.pdf SEKAB Specification] * [http://www.chemicalweekly.com/Profiles/Ethyl_Acetate.pdf A Techno Commercial Profile of Ethyl Acetate in India] [[Category:Flavors]] [[Category:Acetates]] [[Category:Esters]] [[Category:Carboxylate esters]] [[Category:Ester solvents]] [[de:Ethylacetat]] [[es:Etanoato de etilo]] [[fr:Acétate d'éthyle]] [[id:Etil asetat]] [[it:Acetato di etile]] [[hu:Etil-acetát]] [[lv:Etilacetāts]] [[nl:Ethylacetaat]] [[ja:酢酸エチル]] [[no:Etylacetat]] [[pl:Octan etylu]] [[pt:Acetato de etila]] [[ru:Этилацетат]] [[sl:Etil acetat]] [[fi:Etyyliasetaatti]] [[sv:Etylacetat]] [[vi:Axetat etyl]] [[zh:乙酸乙酯]]