Benzoin


Benzoin
Benzoin
Identifiers
CAS number 119-53-9 YesY
PubChem 8400
ChemSpider 8093 YesY
UNII L7J6A1NE81 YesY
KEGG C01408 YesY
ChEBI CHEBI:17682 YesY
ChEMBL CHEMBL190677 YesY
Jmol-3D images Image 1
Image 2
Properties
Molecular formula C14H12O2
Molar mass 212.24 g mol−1
Appearance off-white crystals
Density 1.31 g/cm3
Melting point

132-137 °C

Boiling point

344 °C

Solubility in water Slightly Soluble
Solubility in Chlorine Soluble
Hazards
NFPA 704
NFPA 704.svg
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0
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Benzoin (pronounced /ˈbɛnzoʊ.ɨn, -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.

Contents

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 with, copper(II), nitric acid, or oxone.[5] In one study, this reaction is carried out with atmospheric oxygen and basic alumina in dichloromethane.[6]

References

  1. ^ Wöhler, Liebig; Liebig (1832). "Untersuchungen über das Radikal der Benzoesäure". Annalen der Pharmacie 3 (3): 249–282. doi:10.1002/jlac.18320030302. 
  2. ^ N. Zinin (1839). "Beiträge zur Kenntniss einiger Verbindungen aus der Benzoylreihe". Annalen der Pharmacie 31 (3): 329–332. doi:10.1002/jlac.18390310312. 
  3. ^ N. Zinin (1840). "Ueber einige Zersetzungsprodukte des Bittermandelöls". Annalen der Pharmacie 34 (2): 186–192. doi:10.1002/jlac.18400340205. 
  4. ^ 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
  5. ^ Clarke, H. T.; Dreger.E. E. (1941), "Benzil", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0087 ; Coll. Vol. 1: 87 
  6. ^ 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. http://www.arkat-usa.org/ark/journal/2006/I10_General/1798/06-1798JP%20as%20published%20mainmanuscript.asp. 

External links

  • Benzoin synthesis, Organic Syntheses, Coll. Vol. 1, p.94 (1941); Vol. 1, p.33 (1921)

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Synonyms:

Look at other dictionaries:

  • Benzoin — Ben*zoin (b[e^]n*zoin ), n. [Cf. F. benjoin, Sp. benjui, Pg. beijoin; all fr. Ar. lub[=a]n j[=a]w[=i] incense form Sumatra (named Java in Arabic), the first syllable being lost. Cf. {Benjamin}.] Note: [Called also {benjamin}.] 1. A resinous… …   The Collaborative International Dictionary of English

  • benzoin — balsamic resin obtained from a tree (Styrax benzoin) of Indonesia, 1560s (earlier as bengewine, 1550s), from M.Fr. benjoin (16c.), which comes via Spanish, Portuguese, or Italian from Arabic luban jawi incense of Java (actually Sumatra, with… …   Etymology dictionary

  • Benzoin — Benzoin, Benzol u. Benzon, s.u. Benzoyl B) …   Pierer's Universal-Lexikon

  • Benzoīn — Benzoīn, Baum, s. Styrax …   Meyers Großes Konversations-Lexikon

  • benzoin — [ben′zō in΄, ben zō′in; ben′zoin΄] n. [Fr benjoin < It benzoino < Ar lubān jāwī, incense of Java: lu dropped because falsely assumed to be the article] 1. a balsamic resin obtained from certain tropical Asiatic trees (genus Styrax of the… …   English World dictionary

  • Benzoin — Strukturformel Allgemeines Name Benzoin Andere Namen 2 Hy …   Deutsch Wikipedia

  • benzoin — benzoin1 /ben zoh in, zoyn, ben zoh in/, n. 1. Also called gum benjamin, gum benzoin. a reddish brown, aromatic balsamic resin occurring in almondlike fragments and having a vanillalike odor, obtained from trees of the genus Styrax, esp. S.… …   Universalium

  • Benzoin — Ben|zo|in [zu ↑ Benzoe], das; s, e: Syn.: 2 Hydroxy 1,2 diphenylethanon: ein ↑ Acyloin, das natürlicherweise im Benzoeharz (Benzoin) vorkommt oder durch Benzoin Addition (früher: B. Kondensation, vgl. Acyloin Addition) herzustellen ist. * * *… …   Universal-Lexikon

  • benzoin — benzoinis stirakas statusas T sritis vardynas apibrėžtis Stirakinių šeimos prieskoninis, vaistinis augalas (Styrax benzoin), paplitęs atogrąžų Azijoje. Iš jo gaunami lipai, eterinis aliejus ir derva. atitikmenys: lot. Styrax benzoin angl.… …   Lithuanian dictionary (lietuvių žodynas)

  • benzoin — A balsamic resin obtained from Styrax b. (family Styracaceae), used as a stimulant expectorant, but usually by inhalation in laryngitis and bronchitis; it retards rancidification of fats and is used for this purpose in the official benzoinated… …   Medical dictionary