Acetamide

Production

Laboratory scale

Acetamide can be produced in the laboratory from ammonium acetate by dehydration: : [NH4][CH3CO2] → CH3C(O)NH2 + H2O

Alternatively acetamide can be obtained in excellent yield via ammonolysis of acetylacetone under conditions commonly used in reductive amination.

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

Industrial scale

In a similar fashion to some laboratory methods, acetamide is produced by dehydrating ammonium acetate or via the hydration of acetonitrile, a byproduct of the production of acrylonitrile: : CH3CN + H2O → CH3C(O)NH2

Uses

Acetamide is used as a plasticizer and an industrial solvent. Molten acetamide is good solvent with a broad range of applicability. Notably, its dielectric constant is higher than most organic solvents, allowing it to dissolve inorganic compounds with solubilities closely analogous to that of water. Acetamide has uses in electrochemistry and the organic synthesis of pharmaceuticals, pesticides, and antioxidants for plastics. It is a precursor to thioacetamide.

Occurrence

Acetamide has been detected near the center of the Milky Way galaxy. 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 on Earth) can form in space.

On 30 July 2015, scientists reported that upon the first touchdown of the Philae lander on comet 67/P surface, measurements by the COSAC and Ptolemy instruments revealed sixteen organic compounds, four of which – acetamide, acetone, methyl isocyanate, and propionaldehyde – 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.

References

References

1. (2014). "Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book)". [[Royal Society of Chemistry.
2. ''[[The Merck Index]]'', 14th Edition, '''36'''
3. (2016). "CRC Handbook of Chemistry and Physics". [[CRC Press]].
4. (June 18, 2018). "CRC Handbook of Chemistry and Physics". CRC Press.
5. The related compound [[Dimethylacetamide. ''N'',''N''-dimethylacetamide]] (DMA) is more widely used, but it is not prepared from acetamide. Acetamide can be considered an intermediate between [[acetone]], which has two methyl (CH₃) groups either side of the carbonyl (CO), and [[urea]] which has two amide (NH₂) groups in those locations. Acetamide is also a naturally occurring mineral[https://www.mindat.org/min-13.html Mindat: Naturally occurring acetamide]
6. Warr, L.N.. (2021). "IMA-CNMNC approved mineral symbols". Mineralogical Magazine.
7. (2003). "A new refinement of the orthorhombic polymorph of acetamide". Acta Crystallographica Section E.
8. (1923). "Acetamide".
9. (1939). "Preparation of Certain Amines". [[J. Am. Chem. Soc.]].
10. "Acetic Acid".
11. Stafford, O. F.. (1933). "Acetamide as a Solvent". [[J. Am. Chem. Soc.]].
12. Wagner, Frank S.. (2002). "Kirk-Othmer Encyclopedia of Chemical Technology". John Wiley & Sons.
13. Schwarz, G.. (1945). "2,4-Dimethylthiazole".
14. (2006). "Detection of Acetamide (CH₃CONH₂): The Largest Interstellar Molecule with a Peptide Bond". [[Astrophys. J.]].
15. Jordans, Frank. (30 July 2015). "Philae probe finds evidence that comets can be cosmic labs". The Washington Post.
16. (30 July 2015). "Science on the Surface of a Comet". European Space Agency.
17. (31 July 2015). "Philae's First Days on the Comet - Introduction to Special Issue". [[Science (journal).
18. "Acetamide". Mindat.org.
19. "Acetamide". RRUFF Project.