Acetophenone

[[Category:NFPA-H={{{NFPA-H}}}]]

Acetophenone
IUPAC name 1-phenylethanone
Other names Phenyl methyl ketone, ACP, Phenylethanone
Identifiers
CAS number	98-86-2 Y
PubChem	7410
ChemSpider	7132 Y
UNII	RK493WHV10 Y
DrugBank	DB04619
KEGG	C07113 Y
ChEBI	CHEBI:27632 Y
ChEMBL	CHEMBL274467 Y
Jmol-3D images	Image 1 Image 2
SMILES O=C(c1ccccc1)C CC(=O)c1ccccc1
InChI InChI=1S/C8H8O/c1-7(9)8-5-3-2-4-6-8/h2-6H,1H3 Y Key: KWOLFJPFCHCOCG-UHFFFAOYSA-N Y InChI=1/C8H8O/c1-7(9)8-5-3-2-4-6-8/h2-6H,1H3 Key: KWOLFJPFCHCOCG-UHFFFAOYAT
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	External MSDS
EU classification	Xn
NFPA 704	2   0
Flash point	77 °C
Supplementary data page
Structure and properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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.

Production

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.

Uses

Precursor to resins

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. These modified resins are again found in coatings, inks, as well as adhesives.

Precursor to styrene

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.

C₆H₅CH(OH)CH₃ → C₆H₅CH=CH₂ + H₂O

Use in pharmaceutical and related areas

Acetophenone is a raw material for the synthesis of some pharmaceuticals and is also listed as an approved excipient by the U.S. FDA. 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.

Niche uses

Acetophenone is used to create fragrances that resemble almond, cherry, honeysuckle, jasmine, and strawberry. It is used in chewing gum. 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, as it costs far less and proves as satisfying to consumers this way.

Natural occurrence

Acetophenone occurs naturally in many foods including apple, cheese, apricot, banana, beef, and cauliflower.

Pharmacology

In the late 19th and early 20th centuries, acetophenone was used in medicine. It was marketed as a hypnotic and anticonvulsant under brand name Hypnone. The typical dosage was 0.12 to 0.3 milliliters. It was considered to have superior sedative effects to both paraldehyde and chloral hydrate. In humans, acetophenone is metabolized to benzoic acid, carbonic acid, and acetone.