Acetophenone
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| Names | |||
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| Preferred IUPAC name
1-Phenylethan-1-one[1] | |||
| Other names | |||
| Identifiers | |||
3D model (JSmol)
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| Abbreviations | ACP | ||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider | |||
| DrugBank | |||
| ECHA InfoCard | 100.002.462 | ||
| KEGG | |||
PubChem CID
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| UNII | |||
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| Properties | |||
| C8H8O | |||
| Molar mass | 120.15 g·mol−1 | ||
| Density | 1.028 g/cm3 | ||
| Melting point | 19–20 °C (66–68 °F; 292–293 K) | ||
| Boiling point | 202 °C (396 °F; 475 K) | ||
| 5.5 g/L at 25 °C 12.2 g/L at 80 °C | |||
| -72.05·10−6 cm3/mol | |||
| Hazards | |||
| Safety data sheet | MSDS | ||
| NFPA 704 | |||
| Flash point | 77 °C (171 °F; 350 K) | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
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| Infobox references | |||
Acetophenone is the organic compound with the formula C6H5C(O)CH3 (also represented by the pseudoelement symbols PhAc or BzMe). It is the simplest aromatic ketone. This colorless, viscous liquid is a precursor to useful resins and fragrances.[2]
Contents
Production[edit]
Acetophenone is recovered as a by-product of the oxidation of ethylbenzene to ethylbenzene hydroperoxide. Ethylbenzene hydroperoxide is an intermediate in the commercial production of propylene oxide via the propylene oxide - styrene co-product process.[3] Ethylbenzene hydroperoxide is primarily converted to 1-phenylethanol (α-methylbenzyl alcohol) in the process with a small amount of by-product acetophenone. Acetophenone is recovered or hydrogenated to 1-phenylethanol which is then dehydrated to produce styrene. [2]
Uses[edit]
Precursor to resins[edit]
Commercially significant resins are produced from treatment of acetophenone with formaldehyde and a base. The resulting copolymers are conventionally described with the formula [(C6H5COCH)x(CH2)x]n, resulting from aldol condensation. These substances are components of coatings and inks. Modified acetophenone-formaldehyde resins are produced by the hydrogenation of the aforementioned ketone-containing resins. The resulting polyol can be further crosslinked with diisocyanates.[2] The modified resins are found in coatings, inks and adhesives.
Niche uses[edit]
Acetophenone is an ingredient in fragrances that resemble almond, cherry, honeysuckle, jasmine, and strawberry. It is used in chewing gum.[4] It is also listed as an approved excipient by the U.S. FDA.[5]
Laboratory reagent[edit]
In instructional laboratories,[6] acetophenone is converted to styrene in a two-step process that illustrates the reduction of carbonyls using hydride and the dehydration of alcohols:
- 4 C6H5C(O)CH3 + NaBH4 + 4 H2O → 4 C6H5CH(OH)CH3 + NaOH + B(OH)3 → C6H5CH=CH2
A similar two-step process is used industrially, but reduction step is performed by hydrogenation over a copper catalyst.[2]
- C6H5C(O)CH3 + H2 → C6H5CH(OH)CH3
Being prochiral, acetophenone is also a popular test substrate for asymmetric hydrogenation experiments.
Drugs[edit]
Acetophenone is used for the synthesis of many pharmaceuticals.[7][8]
A Mannich reaction with dimethylamine and formaldehyde gives β-dimethylaminopropiophenone.[9] Using diethylamine instead gives the diethylamino analog.
Natural occurrence[edit]
Acetophenone occurs naturally in many foods including apple, cheese, apricot, banana, beef, and cauliflower. It is also a component of castoreum, the exudate from the castor sacs of the mature beaver.[10]
Pharmacology[edit]
In the late 19th and early 20th centuries, acetophenone was used in medicine.[11] It was marketed as a hypnotic and anticonvulsant under brand name Hypnone. The typical dosage was 0.12 to 0.3 milliliters.[12] It was considered to have superior sedative effects to both paraldehyde and chloral hydrate.[13] In humans, acetophenone is metabolized to benzoic acid, carbonic acid, and acetone.[14] Hippuric acid occurs as an indirect metabolite and its quantity in urine may be used to confirm acetophenone exposure,[15] although other substances, like toluene, also induce hippuric acid in urine.[16]
Toxicity[edit]
The LD50 is 815 mg/kg (oral, rats).[2] Acetophenone is currently listed as a Group D carcinogen indicating that it does not produce carcinogenic effects in humans.
References[edit]
- ^ a b Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 723. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
- ^ a b c d e Siegel, Hardo; Eggersdorfer, Manfred, "Ketones", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a15_077
- ^ "Archived copy" (PDF). Archived (PDF) from the original on 2017-10-07. Retrieved 2017-10-07.
- ^ Burdock, George A. (2005), Fenaroli's Handbook of Flavor Ingredients (5th ed.), CRC Press, p. 15, ISBN 0-8493-3034-3, archived from the original on 2014-09-25
- ^ "Inactive Ingredient Search for Approved Drug Products". Archived from the original on 2013-05-04.
- ^ Wilen, Samuel H.; Kremer, Chester B.; Waltcher, Irving (1961). "Polystyrene—A multistep synthesis: For the undergraduate organic chemistry laboratory". J. Chem. Educ. 38 (6): 304–305. doi:10.1021/ed038p304.
- ^ Sittig, Marshall (1988). Pharmaceutical Manufacturing Encyclopedia. pp. 39, 177. ISBN 978-0-8155-1144-1.
- ^ Gadamasetti, Kumar; Tamim Braish (2007). Process Chemistry in the Pharmaceutical Industry, Volume 2. pp. 142–145. ISBN 978-0-8493-9051-7.
- ^ Maxwell, Charles E. (1943). "β-Dimethylaminopropiophenone Hydrochloride". Organic Syntheses. 23: 30.
- ^ Müller-Schwarze, D.; Houlihan, P. W. (April 1991). "Pheromonal activity of single castoreum constituents in beaver, Castor canadensis". Journal of Chemical Ecology. 17 (4): 715–34. doi:10.1007/BF00994195. PMID 24258917.
- ^ Budavari, Susan, ed. (1996), The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (12th ed.), Merck, ISBN 0911910123
- ^ Bartholow, Roberts (1908). A Practical Treatise on Materia Medica and Therapeutics. Appleton & Co.
- ^ Norman, Conolly (1887). "Cases illustrating the sedative effects of aceto-phenone". Journal of Mental Science. 32: 519.
- ^ "Hypnone – The new hypnotic". Journal of the American Medical Association. 5: 632. 1885. doi:10.1001/jama.1885.02391220016006.
- ^ CID 7410 from PubChem
- ^ "The Netherlands Center for Occupational Diseases (NCvB): toluene (Dutch)" (PDF). beroepsziekten.nl. Retrieved 19 April 2018.
