Benzoin

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Benzoin
Identifiers
CAS number	[119-53-9]
SMILES	O=C(c2ccccc2)C(O)c1ccccc1
Properties
Molecular formula	C14H12O2
Molar mass	212.25 g/mol
Density	1.31 g/cm3
Melting point	137 °C
Boiling point	344 °C
Solubility in water	Slightly Soluble
Solubility in Chlorine	Soluble
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

"Benzoin" is also used to describe benzoin resin, which does not contain the benzoin described on this page.

Benzoin or 2-Hydroxy-2-phenylacetophenone or 2-Hydroxy-1,2-Diphenylethanone or desyl alcohol or bitter almond oil camphor is an organic compound consisting of an ethylene bridge flanked by phenyl groups and with a hydroxyl and a ketone functional group. It comes as off-white crystals, with a light camphor odor. Benzoin is synthesized from benzaldehyde in the benzoin condensation.

Its main uses are:

• photocatalyst in photopolymerization and a photoinitiator
• raw material for benzil by organic oxidation with nitric acid or oxone. In one study,^[1] this reaction is carried out with atmospheric oxygen and basic alumina in dichloromethane.

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.

[edit] History

Benzoin was first synthesized in 1832 by Justus von Liebig and Friedrich Woehler during the research on bitter almond oil, which was benzaldehyde with traces of hydrocyanic acid.^[2] The catalytic synthesis by the benzoin condensation was improved by the research of Nikolay Zinin during his time with Liebig. ^[3][4]

[edit] References

• Synthesis