Acetanilide

Last updated
Acetanilide
Acetanilid.svg
Acetanilide Ball and Stick.png
Acetanilide Space Fill.png
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 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 203-150-7
82833
KEGG
PubChem CID
RTECS number
  • AD7350000
UNII
  • InChI=1S/C8H9NO/c1-7(10)9-8-5-3-2-4-6-8/h2-6H,1H3,(H,9,10) Yes check.svgY
    Key: FZERHIULMFGESH-UHFFFAOYSA-N Yes check.svgY
  • 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 [2] [3]
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) [4]
2.71
Hazards [5] [6]
GHS labelling:
GHS-pictogram-exclam.svg
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).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)
Acetanilide crystals on a watch glass Acetanilide Crystals.jpg
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.

Contents

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 inhibitor of hydrogen peroxide decomposition and is used to stabilize cellulose ester varnishes. It has also found uses in the intermediation in 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. ↑ The presence of aniline as an impurity in 19th century batches of acetanilide drugs cannot be ruled out. In this respect, paracetamol (acetaminophen) is safer than acetanilide, as (1) the corresponding impurity would be 4-aminophenol, which is less toxic than aniline; and (2) in vivo hydrolysis of the amide group in paracetamol appears to be negligible.

Related Research Articles

An antipyretic is a substance that reduces fever. Antipyretics cause the hypothalamus to override a prostaglandin-induced increase in temperature. The body then works to lower the temperature, which results in a reduction in fever.

<span class="mw-page-title-main">Paracetamol</span> Common medication for pain and fever

Paracetamol is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is a widely used over the counter medication and common brand names include Tylenol and Panadol.

<span class="mw-page-title-main">Aniline</span> Organic compound (C₆H₅NH₂); simplest aromatic amine

Aniline is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans.

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<span class="mw-page-title-main">Phenacetin</span> Pharmaceutical drug

Phenacetin is a pain-relieving and fever-reducing drug, which was widely used following its introduction in 1887. It was withdrawn from medicinal use as dangerous from the 1970s.

<span class="mw-page-title-main">Hepatotoxicity</span> Liver damage caused by a drug or chemical

Hepatotoxicity implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn from the market after approval.

<span class="mw-page-title-main">Nitrobenzene</span> Chemical compound

Nitrobenzene is an organic compound with the chemical formula C6H5NO2. It is a water-insoluble pale yellow oil with an almond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale from benzene as a precursor to aniline. In the laboratory, it is occasionally used as a solvent, especially for electrophilic reagents.

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Butalbital/acetaminophen, sold under the brand name Butapap among others, is a combination medication used to treat tension headaches and migraine headaches. It contains butalbital, a barbiturate and paracetamol (acetaminophen), an analgesic. Versions also containing caffeine are sold under the brand name Fioricet among others. It is taken by mouth. The combination is also sold with codeine.

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Nitrophenols are compounds of the formula HOC6H5−x(NO2)x. The conjugate bases are called nitrophenolates. Nitrophenols are more acidic than phenol itself.

<span class="mw-page-title-main">4-Aminophenol</span> Chemical compound

4-Aminophenol (or para-aminophenol or p-aminophenol) is an organic compound with the formula H2NC6H4OH. Typically available as a white powder, it is commonly used as a developer for black-and-white film, marketed under the name Rodinal.

<span class="mw-page-title-main">NAPQI</span> Toxic byproduct of acetaminophen

NAPQI, also known as NAPBQI or N-acetyl-p-benzoquinone imine, is a toxic byproduct produced during the xenobiotic metabolism of the analgesic paracetamol (acetaminophen). It is normally produced only in small amounts, and then almost immediately detoxified in the liver.

<span class="mw-page-title-main">AM404</span> Active metabolite of paracetamol

AM404, also known as N-arachidonoylphenolamine, is an active metabolite of paracetamol (acetaminophen), responsible for all or part of its analgesic action and anticonvulsant effects. Chemically, it is the amide formed from 4-aminophenol and arachidonic acid.

<i>N</i>-Methylphenethylamine Chemical compound

N-Methylphenethylamine (NMPEA) is a naturally occurring trace amine neuromodulator in humans that is derived from the trace amine, phenethylamine (PEA). It has been detected in human urine and is produced by phenylethanolamine N-methyltransferase with phenethylamine as a substrate, which significantly increases PEA's effects. PEA breaks down into phenylacetaldehyde which is further broken down into phenylacetic acid by monoamine oxidase. When this is inhibited by monoamine oxidase inhibitors, it allows more of the PEA to be metabolized into nymphetamine (NMPEA) and not wasted on the weaker inactive metabolites.

<span class="mw-page-title-main">Paracetamol poisoning</span> Toxicity due to paracetamol overdose

Paracetamol poisoning, also known as acetaminophen poisoning, is caused by excessive use of the medication paracetamol (acetaminophen). Most people have few or non-specific symptoms in the first 24 hours following overdose. These symptoms include feeling tired, abdominal pain, or nausea. This is typically followed by absence of symptoms for a couple of days, after which yellowish skin, blood clotting problems, and confusion occurs as a result of liver failure. Additional complications may include kidney failure, pancreatitis, low blood sugar, and lactic acidosis. If death does not occur, people tend to recover fully over a couple of weeks. Without treatment, death from toxicity occurs 4 to 18 days later.

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<span class="mw-page-title-main">Bernard Beryl Brodie</span> American biochemist

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David Lester was an American biochemist who did extensive studies of alcoholism and was a professor at Rutgers University.

An endocannabinoid enhancer (eCBE) is a type of cannabinoidergic drug that enhances the activity of the endocannabinoid system by increasing extracellular concentrations of endocannabinoids. Examples of different types of eCBEs include fatty acid amide hydrolase (FAAH) inhibitors, monoacylglycerol lipase (MAGL) inhibitors, and endocannabinoid transporter (eCBT) inhibitors. An example of an actual eCBE is AM404, the active metabolite of the analgesic paracetamol and a dual FAAH inhibitor and eCBRI.

References

  1. 1 2 "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 846. doi:10.1039/9781849733069-FP001. 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. ↑ Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. C-67. ISBN   0-8493-0462-8..
  3. ↑ Acetanilide (PDF), SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, September 2003.
  4. ↑ Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. pp. 5–88. ISBN   9781498754293.
  5. 1 2 "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. ↑ See, e.g., The preparation of acetanilide from aniline, Department of Chemistry, University of the West Indies at Mona, Jamaica, retrieved 2009-08-26; Reeve, Wilkins; Lowe, Valerie C. (1979), "Preparation of Acetanilide from Nitrobenzene", J. Chem. Educ., 56 (7): 488, Bibcode:1979JChEd..56..488R, 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. 1 2 Brodie, B. B.; Axelrod, J. (1948), "The estimation of acetanilide and its metabolic products, aniline, N-acetyl p-aminophenol and p-aminophenol (free and total conjugated) in biological fluids and tissues", J. Pharmacol. Exp. Ther., 94 (1): 22–28, PMID   18885610 .
  13. ↑ Bertolini, A.; Ferrari, A.; Ottani, A.; Guerzoni, S.; Tacchi, R.; Leone, S. (2006), "Paracetamol: new vistas of an old drug", CNS Drug Reviews, 12 (3–4): 250–75, doi:10.1111/j.1527-3458.2006.00250.x, PMC   6506194 , PMID   17227290 .
  14. ↑ Multiple sources:
    • Lester, D.; Greenberg, L. A. (1947), "Metabolic fate of acetanilide and other aniline derivatives. II. Major metabolites of acetanilide in the blood", J. Pharmacol. Exp. Ther., 90 (1): 68–75, PMID   20241897 .
    • Brodie, B. B.; Axelrod, J. (1948), "The fate of acetanilide in man" (PDF), J. Pharmacol. Exp. Ther., 94 (1): 29–38, PMID   18885611
    • Flinn, Frederick B.; Brodie, Bernard B. (1948), "The effect on the pain threshold of N-acetyl p-aminophenol, a product derived in the body from acetanilide", J. Pharmacol. Exp. Ther., 94 (1): 76–77, PMID   18885618 .

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

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