5,8-Dihydroxy-1,4-naphthoquinone

5,8-Dihydroxy-1,4-naphthoquinone

Names
IUPAC name 5,8-dihydroxynaphthalene-1,4-dione
Other names Dihydroxynaphthoquinone
Identifiers
ChEBI	CHEBI:28849
ChEMBL	ChEMBL274056
ChemSpider	9735
Jmol interactive 3D	Image Image
PubChem	10141
InChI InChI=1S/C10H6O4/c11-5-1-2-6(12)10-8(14)4-3-7(13)9(5)10/h1-4,11-12H Key: RQNVIKXOOKXAJQ-UHFFFAOYSA-N 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	190.15 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

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 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.