Acetanilide

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(Redirected from
Antifebrin
)
Acetanilide
Acetanilide
Names
Preferred IUPAC name
N-Phenylacetamide[1]
Other names
Acetanilide[1]
N-Phenylethanamide
Identifiers
3D model (
JSmol
)
606468
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
 100.002.864 Edit this at Wikidata
EC Number
  • 203-150-7
82833
KEGG
RTECS number
  • AD7350000
UNII
  • InChI=1S/C8H9NO/c1-7(10)9-8-5-3-2-4-6-8/h2-6H,1H3,(H,9,10) checkY
    Key: FZERHIULMFGESH-UHFFFAOYSA-N checkY
  • InChI=1/C8H9NO/c1-7(10)9-8-5-3-2-4-6-8/h2-6H,1H3,(H,9,10)
    Key: FZERHIULMFGESH-UHFFFAOYAA
  • O=C(Nc1ccccc1)C
Properties[3][4]
C8H9NO
Molar mass 135.166 g·mol−1
Odor Odorless
Density 1.219 g/cm3
Melting point 113–115 °C (235–239 °F; 386–388 K)
Boiling point 304 °C (579 °F; 577 K)
<0.56 g/100 mL (25 °C)
Solubility Soluble in ethanol, diethyl ether, acetone, benzene
log P 1.16 (23 °C)
Vapor pressure 2 Pa (20 °C)
Acidity (pKa) 0.5 (25 °C, H2O) (conjugate acid)[2]
2.71
Hazards[5][6]
GHS labelling:
Acute Tox. (oral) 4
Warning
H302
P264, P270, P301+P312, P330, P501
Flash point 174 °C (345 °F; 447 K)
545 °C (1,013 °F; 818 K)
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)
Acetanilide crystals on a watch glass

Acetanilide[7] is an odourless solid chemical of leaf or flake-like appearance. It is also known as N-phenylacetamide, acetanil, or acetanilid, and was formerly known by the trade name Antifebrin.

Preparation and properties

Acetanilide can be produced by reacting acetic anhydride with aniline:

C6H5NH2 + (CH3CO)2O → C6H5NHCOCH3 + CH3COOH

The preparation used to be a traditional experiment in introductory organic chemistry lab classes,[8] but it has now been widely replaced by the preparation of either paracetamol or aspirin, both of which teach the same practical techniques (especially recrystallization of the product) but which avoid the use of aniline, a suspected carcinogen.

Acetanilide is slightly

soluble in water, and stable under most conditions.[5]
Pure crystals are plate shaped and appear colorless, white, or in between.

Applications

Acetanilide is used as an

rubber accelerator synthesis, dyes and dye intermediate synthesis, and camphor synthesis.[9] Acetanilide is used for the production of 4-acetamidobenzenesulfonyl chloride, a key intermediate for the manufacture of the sulfa drugs.[10]

In the 19th century acetanilide was one of a large number of compounds used as experimental photographic developers.

Pharmaceutical use

Acetanilide was the first aniline derivative found to possess analgesic as well as antipyretic properties, and was quickly introduced into medical practice under the names of Antifebrin by A. Cahn and P. Hepp in 1886.[11] But its (apparent) unacceptable toxic effects, the most alarming being cyanosis due to methemoglobinemia and ultimately liver and kidney damage,[12] prompted the search for supposedly less toxic aniline derivatives such as phenacetin.[13] After several conflicting results over the ensuing fifty years, it was established in 1948 that acetanilide was mostly metabolized to paracetamol (acetaminophen) in the human body, and that it was this metabolite that was responsible for the analgesic and antipyretic properties.[12][14] The observed methemoglobinemia after acetanilide administration was ascribed to the small proportion of acetanilide that is hydrolyzed to aniline in the body.[note 1] Acetanilide is no longer used as a drug, although the efficacy of its metabolite paracetamol (acetaminophen) is well known.

See also

Notes

  1. 4-aminophenol
    , which is less toxic than aniline; and (2) in vivo hydrolysis of the amide group in paracetamol appears to be negligible.

References

  1. ^
    ISBN 978-0-85404-182-4
    . N-Phenyl derivatives of primary amides are called 'anilides' and may be named using the term 'anilide' in place of 'amide' in systematic or retained names of amides. (…) However, names expressing N-substitution by a phenyl group on an amide are preferred IUPAC names.
  2. ISBN 9781498754293
    .
  3. ISBN 0-8493-0462-8
    ..
  4. ^ Acetanilide (PDF), SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, September 2003.
  5. ^ a b "Safety data for acetanilide". Physical Chemistry Laboratory, University of Oxford. Archived from the original on 2002-06-23..
  6. ^ "HSNO Chemical Classification Information Database". New Zealand: Environmental Risk Management Authority. Archived from the original on October 13, 2022. Retrieved August 26, 2009.
  7. ^ Acetanilide, archived from the original on 2007-11-25, retrieved 2007-12-29.
  8. doi:10.1021/ed056p488
    : the latter preparation includes the reduction of nitrobenzene to aniline.
  9. ^ PubChem. "Acetanilide". pubchem.ncbi.nlm.nih.gov. Retrieved 2022-12-10.
  10. ^ Ashford's Dictionary of Industrial Chemicals (Third ed.). 2011. p. 33.
  11. ^ Cahn, A.; Hepp, P. (1886), "Das Antifebrin, ein neues Fiebermittel", Centralbl. Klin. Med., 7: 561–64.
  12. ^
    PMID 18885610
    .
  13. PMID 17227290
    .
  14. ^ Multiple sources:

External links

"Making an old pain and fever medication" by NileRed. YouTube. May 21, 2017.

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