Naphthazarin

Naphthazarin, often called 5,8-dihydroxy-1,4-naphthoquinone or 5,8-dihydroxy-1,4-naphthalenedione (IUPAC), is a naturally occurring[1][2] organic compound with formula C
₁₀H
₆O
₄, formally derived from 1,4-naphthoquinone through replacement of two hydrogen atoms by hydroxyl (OH) groups. It is thus one of many dihydroxynaphthoquinone structural isomers.

Naphthazarin

Names
IUPAC name 5,8-dihydroxynaphthalene-1,4-dione
Other names Dihydroxynaphthoquinone
Identifiers
3D model (JSmol)	Interactive image Interactive image
ChEBI	CHEBI:28849^N
ChEMBL	ChEMBL274056^Y
ChemSpider	9735^Y
ECHA InfoCard	100.006.816
PubChem CID	10141
CompTox Dashboard (EPA)	DTXSID00197161
InChI InChI=1S/C10H6O4/c11-5-1-2-6(12)10-8(14)4-3-7(13)9(5)10/h1-4,11-12H^Y Key: RQNVIKXOOKXAJQ-UHFFFAOYSA-N^Y InChI=1/C10H6O4/c11-5-1-2-6(12)10-8(14)4-3-7(13)9(5)10/h1-4,11-12H Key: RQNVIKXOOKXAJQ-UHFFFAOYAN
SMILES C1=CC(=C2C(=O)C=CC(=O)C2=C1O)O O=C\2c1c(O)ccc(O)c1C(=O)/C=C/2
Properties
Chemical formula	C10H6O4
Molar mass	190.154 g·mol^−1
Melting point	228–232 °C (442–450 °F; 501–505 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is ^YN ?)
Infobox references

Naphthazarin is soluble in 1,4-dioxane from which it crystallizes as deep red needles that melt at 228−232 °C.[3]

Synthesis

Naphtharazin can be prepared by condensation of 1,4-dimethoxybenzene with 2,3-dichloromaleic anhydride followed by reductive dechlorination and reoxidation.[4][5]

Naphtharazin can also be obtained by oxidation of 5,8-dihydroxy-1-tetralone with manganese dioxide (MnO₂).[3]

References

1. Thomson R.H. Naturally Occurring Quinones. Academic Press, London (1971). Quoted by Khalafy and Bruce.
2. Thomson R.H. Naturally Occurring Quinones III. Chapman and Hall, London (1987). Quoted by Khalafy and Bruce.
3. J. Khalafy and J.M. Bruce (2002), Oxidative dehydrogenation of 1-tetralones: Synthesis of juglone, naphthazarin, and α-hydroxyanthraquinones. Journal of Sciences, Islamic Republic of Iran, volume 13 issue 2, pages 131-139.
4. Lewis J.R. and Paul J.J.(1977). Z. Naturforsch., B, 32: 1473. Quoted by Khalafy and Bruce.
5. Huot R. and Brassard P. (1974). Can. J. Chem., 52: 838. Quoted by Khalafy and Bruce.