Acetophenone
| Acetophenone | |
|---|---|
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1-phenylethanone |
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Other names
Phenyl methyl ketone, ACP, Phenylethanone |
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| Identifiers | |
| CAS number | 98-86-2  |
| PubChem | 7410 |
| ChemSpider | 7132 |
| UNII | RK493WHV10 |
| DrugBank | DB04619 |
| KEGG | C07113 |
| ChEBI | CHEBI:27632 |
| ChEMBL | CHEMBL274467 |
| Jmol-3D images | Image 1 Image 2 |
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| Properties | |
| Molecular formula | C8H8O |
| Molar mass | 120.15 g mol−1 |
| Density | 1.028 g/cm³ |
| Melting point |
19–20 °C |
| Boiling point |
202 °C |
| Solubility in water | 5.5 g/L at 25 °C 12.2 g/L at 80 °C |
| Hazards | |
| MSDS | MSDS |
| EU classification |  Xn |
| NFPA 704 |
 2
1
0
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| Flash point | 77 °C |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Acetophenone is the organic compound with the formula C6H5C(O)CH3. It is the simplest aromatic ketone. This colourless, viscous liquid is a precursor to useful resins and fragrances.[1]
Contents |
Production [edit]
Acetophenone can be obtained by a variety of methods. In industry, acetophenone is recovered as a by-product of the oxidation of ethylbenzene, which mainly gives ethylbenzene hydroperoxide for use in the production of propylene oxide.[1]
Uses [edit]
Precursor to resins [edit]
Commercially significant resins are produced from treatment of acetophenone with formaldehyde and base. The resulting polymers are conventionally described with the formula [(C6H5C(O)CH]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.[1] These modified resins are again found in coatings, inks, as well as adhesives.
Precursor to styrene [edit]
In instructional laboratories, acetophenone is converted to styrene in a two step process that illustrates the reduction of carbonyls and the dehydration of alcohols:
- 4 C6H5C(O)CH3 + NaBH4 + 4 H2O → 4 C6H5CH(OH)CH3 + NaOH + B(OH)3
A similar process is used industrially but the hydrogenation step to 1-phenylethanol is done over a copper catalyst.[1]
- C6H5CH(OH)CH3 → C6H5CH=CH2 + H2O
[edit]
Acetophenone is a raw material for the synthesis of some pharmaceuticals[2] [3] and is also listed as an approved excipient by the U.S. FDA.[4] In a 1994 report released by five top cigarette companies in the U.S., acetophenone was listed as one of the 599 additives to cigarettes.[5]
Niche uses [edit]
Acetophenone is used to create fragrances that resemble almond, cherry, honeysuckle, jasmine, and strawberry. It is used in chewing gum.[6] Being prochiral, acetophenone is also a popular test substrate for asymmetric transfer hydrogenation experiments. Acetophenone is also commonly used as a flavouring in many cherry flavoured sweets and drinks.
Natural occurrence [edit]
Acetophenone occurs naturally in many foods including apple, cheese, apricot, banana, beef, and cauliflower.
Pharmacology [edit]
In the late 19th and early 20th centuries, acetophenone was used in medicine.[7] It was marketed as a hypnotic and anticonvulsant under brand name Hypnone. The typical dosage was 0.12 to 0.3 milliliters.[8] It was considered to have superior sedative effects to both paraldehyde and chloral hydrate.[9] In humans, acetophenone is metabolized to benzoic acid, carbonic acid, and acetone.[10]
References [edit]
- ^ a b c d Hardo Siegel, Manfred Eggersdorfer “Ketones” in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, 2002, Wienheim. doi:10.1002/14356007.a15_077
- ^ 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.
- ^ http://www.accessdata.fda.gov/scripts/cder/iig/index.cfm
- ^ "What's in a cigarette?". Archived from the original on 23 May 2006. Retrieved 2006-05-31.
- ^ Burdock, George A. (2005), Fenaroli's Handbook of Flavor Ingredients (5th ed.), CRC Press, p. 15, ISBN 0-8493-3034-3
- ^ The Merck Index, 12th Edition
- ^ Bartholow, Roberts. "A Practical Treatise On Materia Medica And Therapeutics." Appleton & Co, 1908.
- ^ Norman, Conolly. "Cases illustrating the sedative effects of aceto-phenone." Journal of Mental Science, Vol 32, p 519. 1887.
- ^ "Hypnone - The new hypnotic." J Am Med Assoc. Vol 5, p 632. 1885. doi:10.1001/jama.1885.02391220016006
