Acetamide (CH₃CONH₂) | Laboratory & Industrial Grade Reagent

Overview

Acetamide is the amide of acetic acid and the simplest member of the acyclic amide family. It is a white crystalline solid, very soluble in water and in polar organic solvents, with a melting point of about 80 °C and an unusually wide liquid range up to its boiling point at 221 °C.

That combination is what makes it useful. Molten acetamide is a high-boiling, strongly polar solvent that dissolves many salts and organic compounds, so it is used as a reaction medium, as a plasticiser in coatings and textile processing, and as a starting material in organic synthesis. In the laboratory it also serves as a reference amide in spectroscopy, crystallisation and physical-chemistry teaching work, and as a nitrogen source in studies of microbial amidase activity.

Key features

• High-purity grade, ≥ 99.0% assay
• Wide liquid range makes it a useful high-boiling polar solvent
• Very high water solubility, approximately 2000 g/L at 20 °C
• Reference acyclic amide for spectroscopy and physical chemistry
• Established intermediate in fine-chemical synthesis

Identification

Applications

Frequently Asked Questions

Structure and Chemistry

Acetamide is the condensation product of acetic acid and ammonia, with a carbonyl group bonded directly to nitrogen. Delocalisation between the nitrogen lone pair and the carbonyl gives the C–N bond partial double-bond character, which makes the amide group planar, raises the boiling point well above that of comparable esters, and leaves the nitrogen only very weakly basic. The same delocalisation makes the molecule strongly polar, which accounts for its high water solubility and its usefulness as a solvent for ionic compounds.

In water it hydrolyses slowly to acetic acid and ammonia, and quickly under acid or base catalysis at elevated temperature. This is also the route by which damp or old material develops its characteristic ammoniacal smell.

Physical and Chemical Properties

Physical constants are literature values for pure acetamide and are given for guidance. Batch-specific results are reported on the COA.

Handling Notes

• Weigh in a fume hood or ventilated weighing enclosure. Avoid generating dust.
• Reseal the container immediately. Material left open takes up water and begins to hydrolyse.
• Where the material is melted for use as a solvent, heat it in a fume hood and avoid overheating, which accelerates decomposition.
• Incompatible with strong oxidising agents, strong acids and strong bases.
• Keep records of use and quantities held, as local regulations for carcinogens generally require.

Literature and References

1. O'Neil MJ, ed. The Merck Index, 15th ed. Royal Society of Chemistry; 2013.
2. Haynes WM, ed. CRC Handbook of Chemistry and Physics, 97th ed. CRC Press; 2016.
3. International Agency for Research on Cancer. Acetamide. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 71. IARC; 1999:1211–1216.
4. European Chemicals Agency. Acetamide (EC 200-473-5) — registered substance and CLP classification. ECHA.
5. Safe Work Australia. Code of Practice: Managing Risks of Hazardous Chemicals in the Workplace. Safe Work Australia; 2020.

Hazard Identification

Acetamide is listed by the International Agency for Research on Cancer in Group 2B, possibly carcinogenic to humans, on the basis of sufficient evidence of carcinogenicity in experimental animals and inadequate evidence in humans. It is not classified for acute toxicity, skin or eye irritation, or respiratory sensitisation. Dust may still cause mild mechanical irritation of the eyes and respiratory tract.

Precautionary statements: P201 Obtain special instructions before use. P202 Do not handle until all safety precautions have been read and understood. P280 Wear protective gloves, protective clothing and eye protection. P308+P313 IF exposed or concerned: get medical advice. P405 Store locked up. P501 Dispose of contents and container in accordance with local regulations.

Composition

Single-substance product. No hazardous impurities are present above their respective classification thresholds.

First Aid

Handling, Spills and Disposal

• Handle in a fume hood or ventilated weighing enclosure. Avoid generating dust and avoid all unnecessary exposure.
• Do not eat, drink or smoke in the handling area. Wash hands thoroughly after use.
• Store locked up or in a restricted chemical store, segregated from oxidising agents.
• Spills: avoid dust. Collect mechanically or with a HEPA vacuum into a labelled, closed container. Wash the area with water and collect the washings as chemical waste.
• Disposal: dispose of the product, contaminated packaging and spill residues as hazardous chemical waste through a licensed contractor, in accordance with local regulations. Do not discharge to drain.
• Keep a record of quantities held and used, as required for carcinogens under the model WHS Regulations.

Quality Control Specification

Identity Confirmation

Identity is confirmed by melting point and by infrared spectrum against a reference. The characteristic amide bands are the carbonyl stretch near 1660 cm^-1 and the N–H stretches between 3150 and 3400 cm^-1.