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) o-Benzoquinone (no longer recommended) o-Quinone
Identifiers
CAS Number	583-63-1 N
3D model (JSmol)	Interactive image Interactive image
ChEBI	CHEBI:17253 Y
ChemSpider	10941 Y
KEGG	C02351 Y
PubChem CID	11421
UNII	SVD1LJ47R7 Y
InChI InChI=1S/C6H4O2/c7-5-3-1-2-4-6(5)8/h1-4H Y Key: WOAHJDHKFWSLKE-UHFFFAOYSA-N Y InChI=1/C6H4O2/c7-5-3-1-2-4-6(5)8/h1-4H Key: WOAHJDHKFWSLKE-UHFFFAOYAR
SMILES O=C1/C=C\C=C/C1=O C1=CC(=O)C(=O)C=C1
Properties
Chemical formula	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  (what is YN ?)
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.

The molecule has C_2v 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.

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

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