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Acetamide (systematic name:ethanamide) is anorganic compound with the formula CH₃CONH₂. It is anamide derived fromammonia andacetic acid. It finds some use as aplasticizer and as an industrial solvent.^[5] The related compoundN,N-dimethylacetamide (DMA) is more widely used, but it is not prepared from acetamide. Acetamide can be considered an intermediate betweenacetone, which has two methyl (CH₃) groups either side of the carbonyl (CO), andurea which has two amide (NH₂) groups in those locations. Acetamide is also a naturally occurring mineral^[6] with theIMA symbol: Ace.^[7]

Production

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Structure of acetamidehydrogen-bonded dimer fromX-ray crystallography. Selected distances: C-O: 1.243, C-N, 1.325, N---O, 2.925 Å. Color code: red = O, blue = N, gray = C, white = H.^[8]

Laboratory scale

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Acetamide can be produced in the laboratory fromammonium acetate bydehydration:^[9]

[NH₄][CH₃CO₂] → CH₃C(O)NH₂ + H₂O

Alternatively acetamide can be obtained in excellent yield viaammonolysis ofacetylacetone under conditions commonly used inreductive amination.^[10]

It can also be made from anhydrous acetic acid, acetonitrile and very well dried hydrogen chloride gas, using an ice bath, alongside more valuable reagentacetyl chloride. Yield is typically low (up to 35%), and the acetamide made this way is generated as a salt with HCl.

Industrial scale

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In a similar fashion to some laboratory methods, acetamide is produced bydehydrating ammonium acetate or via thehydration ofacetonitrile, a byproduct of the production ofacrylonitrile:^[5]

CH₃CN + H₂O → CH₃C(O)NH₂

Uses

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Acetamide is used as a plasticizer and an industrial solvent.^[5] Molten acetamide is good solvent with a broad range of applicability. Notably, itsdielectric constant is higher than most organic solvents, allowing it to dissolveinorganic compounds with solubilities closely analogous to that of water.^[11] Acetamide has uses in electrochemistry and theorganic synthesis of pharmaceuticals, pesticides, and antioxidants for plastics.^[12] It is a precursor tothioacetamide.^[13]

Occurrence

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Acetamide has been detected near the center of theMilky Way galaxy.^[14] This finding is potentially significant because acetamide has an amide bond, similar to the essential bond between amino acids in proteins. This finding lends support to the theory that organic molecules that can lead to life (as we know it onEarth) can form in space.

On 30 July 2015, scientists reported that upon the first touchdown of thePhilae lander oncomet 67/P's surface, measurements by the COSAC and Ptolemy instruments revealed sixteenorganic compounds, four of which – acetamide,acetone,methyl isocyanate, andpropionaldehyde^[15]^[16]^[17] – were seen for the first time on a comet.

In addition, acetamide is found infrequently on burning coal dumps, as a mineral of the same name.^[18]^[19]

References

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^"Front Matter".Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge:The Royal Society of Chemistry. 2014. p. 841.doi:10.1039/9781849733069-FP001.ISBN 978-0-85404-182-4.
^^a ^b ^c ^dThe Merck Index, 14th Edition,36
^Haynes, William M., ed. (2016).CRC Handbook of Chemistry and Physics (97th ed.).CRC Press. pp. 5–88.ISBN 9781498754293.
^John Rumble (June 18, 2018).CRC Handbook of Chemistry and Physics (99th ed.). CRC Press. pp. 5–3.ISBN 978-1138561632.
^^a ^b ^cCheung, H.; Tanke, R. S.; Torrence, G. P. "Acetic Acid".Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH.doi:10.1002/14356007.a01_045.pub2.ISBN 978-3-527-30673-2.
^Mindat: Naturally occurring acetamide
^Warr, L.N. (2021)."IMA-CNMNC approved mineral symbols".Mineralogical Magazine.85 (3):291–320.Bibcode:2021MinM...85..291W.doi:10.1180/mgm.2021.43.S2CID 235729616.
^Bats, Jan W.; Haberecht, Monika C.; Wagner, Matthias (2003). "A new refinement of the orthorhombic polymorph of acetamide".Acta Crystallographica Section E.59 (10):o1483 –o1485.doi:10.1107/S1600536803019494.
^Coleman, G. H.; Alvarado, A. M. (1923)."Acetamide".Organic Syntheses.3: 3.doi:10.15227/orgsyn.003.0003;Collected Volumes, vol. 1, p. 3.
^Schwoegler, Edward J.;Adkins, Homer (1939). "Preparation of Certain Amines".J. Am. Chem. Soc.61 (12):3499–3502.doi:10.1021/ja01267a081.
^Stafford, O. F. (1933). "Acetamide as a Solvent".J. Am. Chem. Soc.55 (10):3987–3988.doi:10.1021/ja01337a011.
^Wagner, Frank S. (2002).Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons.doi:10.1002/0471238961.0103052023010714.a02.pub2.ISBN 9780471238966.
^Schwarz, G. (1945)."2,4-Dimethylthiazole".Organic Syntheses.25: 35;Collected Volumes, vol. 3, p. 332.
^Hollis, J. M.; Lovas, F. J.; Remijan, A. J.; Jewell, P. R.; Ilyushin, V. V.; Kleiner, I. (2006)."Detection of Acetamide (CH₃CONH₂): The Largest Interstellar Molecule with a Peptide Bond".Astrophys. J.643 (1):L25 –L28.Bibcode:2006ApJ...643L..25H.doi:10.1086/505110.
^Jordans, Frank (30 July 2015)."Philae probe finds evidence that comets can be cosmic labs".The Washington Post. Associated Press. Archived fromthe original on 23 December 2018. Retrieved30 July 2015.
^"Science on the Surface of a Comet". European Space Agency. 30 July 2015. Retrieved30 July 2015.
^Bibring, J.-P.; Taylor, M.G.G.T.; Alexander, C.; Auster, U.; Biele, J.; Finzi, A. Ercoli; Goesmann, F.; Klingehoefer, G.; Kofman, W.; Mottola, S.; Seidenstiker, K.J.; Spohn, T.; Wright, I. (31 July 2015)."Philae's First Days on the Comet - Introduction to Special Issue".Science.349 (6247): 493.Bibcode:2015Sci...349..493B.doi:10.1126/science.aac5116.PMID 26228139.
^"Acetamide". Mindat.org.
^"Acetamide"(PDF).Handbook of Mineralogy. RRUFF Project.

External links

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Look upacetamide in Wiktionary, the free dictionary.

International Chemical Safety Card 0233
"Acetamide". Webmineral.org.

Molecules detected in outer space

Molecules

Diatomic	Aluminium monochloride Aluminium monofluoride Aluminium(II) oxide Argonium Carbon cation Carbon monophosphide Carbon monosulfide Carbon monoxide Cyano radical Diatomic carbon Fluoromethylidynium Helium hydride ion Hydrogen chloride Hydrogen fluoride Hydrogen (molecular) Hydroxyl radical Imidogen Iron(II) oxide Magnesium monohydride Methylidyne radical Nitric oxide Nitrogen (molecular) Oxygen (molecular) Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfanyl Sulfur mononitride Sulfur monoxide Titanium(II) oxide
Triatomic	Aluminium(I) hydroxide Aluminium isocyanide Amino radical Carbon dioxide Carbonyl sulfide CCP radical Chloronium Diazenylium Dicarbon monoxide Disilicon carbide Ethynyl radical Formyl radical Hydrogen cyanide (HCN) Hydrogen isocyanide (HNC) Hydrogen sulfide Hydroperoxyl Iron cyanide Isoformyl Magnesium cyanide Magnesium isocyanide Methylene Methylidynephosphane N₂H⁺ Nitrous oxide Nitroxyl Ozone Potassium cyanide Sodium cyanide Sodium hydroxide Silicon carbonitride c-Silicon dicarbide SiNC Sulfur dioxide Thioformyl Thioxoethenylidene Titanium dioxide Tricarbon Trihydrogen cation Water
Four atoms	Acetylene Ammonia Cyanoethynyl Formaldehyde Fulminic acid HCCN Hydrogen peroxide Hydromagnesium isocyanide Isocyanic acid Isothiocyanic acid Ketenyl Methyl cation Methyl radical Methylene amidogen Propynylidyne Protonated carbon dioxide Protonated hydrogen cyanide Silicon tricarbide Thiocyanic acid Thioformaldehyde Tricarbon monosulfide Tricarbon monoxide
Five atoms	Ammonium ion Butadiynyl Carbodiimide Cyanamide Cyanoacetylene Cyanoformaldehyde Cyanomethyl Cyclopropenylidene Formic acid Isocyanoacetylene Ketene Methane Methoxy radical Methylenimine Propadienylidene Protonated formaldehyde Silane Silicon-carbide cluster
Six atoms	Acetonitrile Cyanobutadiynyl radical Cyclopropenone Diacetylene E-Cyanomethanimine Ethylene Formamide HC₄N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene
Seven atoms	Acetaldehyde Acrylonitrile Vinyl cyanide Cyanodiacetylene Ethylene oxide Glycolonitrile Hexatriynyl radical Methyl isocyanate Methylamine Propyne Vinyl alcohol
Eight atoms	Acetic acid Acrolein Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Hexapentaenylidene Methyl formate Methylcyanoacetylene
Nine atoms	Acetamide Cyanohexatriyne Dimethyl ether Ethanethiol Ethanol Methyldiacetylene N-Methylformamide Octatetraynyl radical Propene Propionitrile
Ten atoms or more	Acetone Benzene Benzonitrile Buckminsterfullerene (C₆₀, C₆₀⁺, fullerene, buckyball) Butyronitrile C₇₀ fullerene Cyanodecapentayne Ethyl formate Ethylene glycol Heptatrienyl radical Methyl acetate Methyl-cyano-diacetylene Methyltriacetylene Propionaldehyde Pyrimidine