1,2-Benzoquinone

1,2-Benzoquinone
Names
Preferred IUPAC name
Cyclohexa-3,5-diene-1,2-dione
Other names
1,2-Benzoquinone (no longer recommended[1])
o-Benzoquinone (no longer recommended[1])
o-Quinone
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
KEGG
UNII
Properties
C6H4O2
Molar mass 108.0964 g/mol
Density 1.424 g/cm3
Boiling point 213.3 °C (415.9 °F; 486.4 K) at 760 mmHg
Hazards
Flash point 76.4 °C (169.5 °F; 349.5 K)
Related compounds
Related compounds
1,4-benzoquinone
quinone
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

1,2-Benzoquinone, also called ortho-benzoquinone, is an organic compound with formula C6H4O2. It is one of the two isomers of quinone, the other being 1,4-benzoquinone. It is a red volatile solid that is soluble in water and ethyl ether. It is rarely encountered because of its instability, but it is of fundamental interest as the parent ortho-quinone, of which many analogues are known.[2]

Structure

The molecule has C2v symmetry. X-ray crystallography shows that the double bonds are localized, with alternatingly long and short C-C distances within the ring. The C=O distances of 1.21 Å are characteristic of ketones.[3]

Preparation and occurrence

1,2-Benzoquinone is produced on oxidation of catechol exposed to air in aqueous solution[4] or by ortho oxidation of a phenol.[4] It is a precursor to melanin.[5]

A strain of the bacterium Pseudomonas mendocina metabolises benzoic acid, yielding 1,2-benzoquinone via catechol.[6]

References

  1. 1 2 Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 728. ISBN 978-0-85404-182-4. doi:10.1039/9781849733069-FP001.
  2. Liao, Chun-Chen; Peddinti, Rama Krishna "Masked o-Benzoquinones in Organic Synthesis" Accounts of Chemical Research 2002, volume 35, pp. 856-866.doi:10.1021/ar000194n
  3. Macdonald, Alistair L.; Trotter, James "Crystal and molecular structure of o-benzoquinone" Journal of the Chemical Society, Perkin Transactions 2: 1973, pp. 476-80. doi:10.1039/P29730000476
  4. 1 2 Magdziak, D.; Rodriguez, A. A.; Van De Water, R. W.; Pettus, T. R. R. (2002). "Regioselective oxidation of phenols to o-quinones with o-iodoxybenzoic acid (IBX)". Org. Lett. 4 (2): 285–288. PMC 1557836Freely accessible. PMID 11796071. doi:10.1021/ol017068j.
  5. Enzymatic Browning in Fruits, Vegetables and Seafoods Section 2.3.2
  6. Chanda Parulekar and Suneela Mavinkurve (2006), Formation of ortho-benzoquinone from sodium benzoate by Pseudomonas mendocina | P=2 d. Indian Journal of Experimental Biology, volume 44, pages 157--162.


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.