Acetamide

Ethanamide, the simplest two-carbon example of an amide linkage.

Formula
C2H5NO
Functional group
Amides
Molar mass
59.07 g/mol
Also known as
Ethanamide, Acetic acid amide, Methanecarboxamide, Acetimidic acid, Ethanimidic acid, Amid kyseliny octove

Overview

Ethanamide, the simplest two-carbon example of an amide linkage.

Nitrogen is attached directly to a carbonyl carbon. Delocalisation of its lone pair reduces its basicity relative to ethylamine and influences the bond geometry. Hydrolysis breaks the acyl–nitrogen linkage under suitable acidic or alkaline conditions, connecting amides with carboxylic-acid chemistry.

Identifiers

Formula
C2H5NO
Functional group
Amides
Molar mass
59.07 g/mol
Also known as
Ethanamide, Acetic acid amide, Methanecarboxamide, Acetimidic acid, Ethanimidic acid, Amid kyseliny octove
Chemical identifiers
SMILES
CC(=O)N
InChI
InChI=1S/C2H5NO/c1-2(3)4/h1H3,(H2,3,4)
PubChem CID
178

Properties

Melting Point
81.16 °C
Boiling Point
222 °C at 760 mm Hg
Density
1.16 g/cm³
Water solubility
In water, 7.05X10+5 mg/L at 24.5 °C

Related compounds

  • Amides

    Ethanamide, the simplest two-carbon example of an amide linkage.

Connected reactions

  • Amide formation: Acetyl chloride → Acetamide

    Ammonia attacks the carbonyl carbon and chloride leaves when the tetrahedral intermediate collapses. Deprotonation gives acetamide, while another ammonia equivalent neutralises the acid to form ammonium chloride.

  • Amide hydrolysis: Acetamide → Ethanoic acid

    Acid activates the amide carbonyl for water addition. Proton transfer makes nitrogen a better leaving group before C-N cleavage; the acyl fragment becomes ethanoic acid and the nitrogen ends as ammonium.

References

  1. PubChem Compound Summary: Acetamide (CID 178)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  2. OpenStax Organic Chemistry: Chemistry of amidesJohn McMurry · OpenStax · 2023

    Supports the qualitative structural interpretation of the recorded molecular structure; no new physical measurement or verified preparative yield is claimed.

  3. OpenStax Organic Chemistry: Basicity of aminesJohn McMurry · OpenStax · 2023

    Supports the qualitative structural interpretation of the recorded molecular structure; no new physical measurement or verified preparative yield is claimed.

  4. Hazardous Substances Data Bank (HSDB): Acetamide — melting pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/178#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-4

  5. Hazardous Substances Data Bank (HSDB): Acetamide — boiling pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/178#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 9

  6. ILO-WHO International Chemical Safety Cards (ICSCs): Acetamide — densityILO-WHO International Chemical Safety Cards (ICSCs)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/178#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.

  7. Hazardous Substances Data Bank (HSDB): Acetamide — solubilityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/178#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Yalkowsky, S.H., He, Yan, Jain, P. Handbook of Aqueous Solubility Data Second Edition. CRC Press, Boca Raton, FL 2010, p. 35