Benzoin (organic compound)
Names | |
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Preferred IUPAC name
2-Hydroxy-1,2-diphenylethan-1-one | |
Other names
2-Hydroxy-2-phenylacetophenone
2-Hydroxy-1,2-diphenylethanone Desyl alcohol Bitter almond oil camphor | |
Identifiers | |
3D model (JSmol)
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3DMet | |
391839 | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.003.938 |
KEGG | |
PubChem CID
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RTECS number |
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C14H12O2 | |
Molar mass | 212.248 g·mol−1 |
Appearance | Off-white crystals |
Density | 1.31 g/cm3 |
Melting point | 134 to 138 °C (273 to 280 °F; 407 to 411 K) |
Boiling point | 344 °C (651 °F; 617 K) |
Slightly soluble | |
Solubility in ethanol | Slightly soluble |
Solubility in alcohol | Soluble |
Solubility in ether | Slightly soluble |
Solubility in chlorine | Soluble |
Hazards | |
GHS hazard statements
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H412 |
P273, P501 | |
NFPA 704 (fire diamond) |
1
1
0 |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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10.000 mg/kg |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
what is ?) | (|
Infobox references | |
Benzoin (/ˈbɛnzoʊ.ɪn/ or /-ɔɪn/) is an organic compound with the formula PhCH(OH)C(O)Ph. It is a hydroxy ketone attached to two phenyl groups. It appears as off-white crystals, with a light camphor-like odor. Benzoin is synthesized from benzaldehyde in the benzoin condensation. It is chiral and it exists as a pair of enantiomers: (R)-benzoin and (S)-benzoin.
Benzoin is not a constituent of benzoin resin obtained from the benzoin tree (Styrax) or tincture of benzoin. The main component in these natural products is benzoic acid.
History[]
Benzoin was first reported in 1832 by Justus von Liebig and Friedrich Woehler during their research on oil of bitter almond, which is benzaldehyde with traces of hydrocyanic acid.[1] The catalytic synthesis by the benzoin condensation was improved by Nikolay Zinin during his time with Liebig.[2][3]
Uses[]
The main uses of benzoin are as a precursor to benzil, which is a photoinitiator.[4] The conversion proceeds by organic oxidation using copper(II),[5] nitric acid, or oxone. In one study, this reaction is carried out with atmospheric oxygen and basic alumina in dichloromethane.[6]
Benzoin can be used in the preparation of several pharmaceutical drugs including oxaprozin, ditazole, and phenytoin.[7]
Preparation[]
Benzoin is prepared from benzaldehyde via the benzoin condensation.[8]
References[]
- ^ Wöhler, Liebig; Liebig (1832). "Untersuchungen über das Radikal der Benzoesäure". Annalen der Pharmacie. 3 (3): 249–282. doi:10.1002/jlac.18320030302. hdl:2027/hvd.hxdg3f.
- ^ N. Zinin (1839). "Beiträge zur Kenntniss einiger Verbindungen aus der Benzoylreihe". Annalen der Pharmacie. 31 (3): 329–332. doi:10.1002/jlac.18390310312.
- ^ N. Zinin (1840). "Ueber einige Zersetzungsprodukte des Bittermandelöls". Annalen der Pharmacie. 34 (2): 186–192. doi:10.1002/jlac.18400340205.
- ^ Hardo Siegel, Manfred Eggersdorfer "Ketones" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, 2002 by Wiley-VCH, Wienheim. doi:10.1002/14356007.a15_077
- ^ Clarke, H. T.; Dreger.E. E. (1941). "Benzil". Organic Syntheses.; Collective Volume, 1, p. 87
- ^ Konstantinos Skobridis; Vassiliki Theodorou; Edwin Weber (2006). "A very simple and chemoselective air oxidation of benzoins to benzils using alumina". Arkivoc. 06-1798JP: 102–106.[permanent dead link]
- ^ U.S. Patent 2,242,775
- ^ Clarke, H. T.; Dreger.E. E. (1941). "Benzil". Organic Syntheses.; Collective Volume, 1, p. 87
External links[]
- Benzoin synthesis, Organic Syntheses, Coll. Vol. 1, p. 94 (1941); Vol. 1, p. 33 (1921)
- Aromatic ketones
- Acyloins