1,4-Naphthoquinone
| Naphthoquinone[1] | |
|---|---|
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| 4a,8a-Dihydronaphthalene-1,4-dione | |
| Other names Naphthoquinone | |
| Identifiers | |
| CAS number | 130-15-4  |
| PubChem | 8530 |
| ChemSpider | 8215 |
| ChEMBL | CHEMBL55934  |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C10H6O2 |
| Molar mass | 158.15 g/mol |
| Density | 1.422 g/cm³ |
| Melting point | 126 °C |
| Boiling point | Begins to sublime at 100 °C |
| Solubility in water | 0.09 g/L |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
1,4-Naphthoquinone or para-naphthoquinone is an organic compound derived from naphthalene. Several isomeric naphthoquinones are known, notably 1,2-naphthoquinone. 1,4-Naphthoquinone forms volatile yellow triclinic crystals and has a sharp odor similar to benzoquinone. It is almost insoluble in cold water, slightly soluble in petroleum ether, and more soluble in polar organic solvents. In alkaline solutions it produces a reddish-brown color. Vitamin K is a derivative of 1,4-naphthoquinone. It is a planar molecule with one aromatic ring fused to a quinone subunit.[2]
Preparation
The industrial synthesis involves aerobic oxidation of naphthalene over a vanadium oxide catalyst:[3]
- C10H8 + 3/2 O2 → C10H6O2 + H2O
In the laboratory, naphthoquinone can be produced by the oxidation of a variety of naphthalene compounds. An inexpensive route involves oxidation of naphthalene with chromium trioxide.[4]
Uses
1,4-Naphthoquinone is mainly used as a precursor to anthroquinone by reaction with butadiene followed by oxidation. Nitration gives 5-nitro-1,4-naphthalenedione, precursor to an aminoanthroquinone that is used as a dye precursor.[3]
Derivatives
Naphthoquinone forms the central chemical structure of many natural compounds, most notably the K vitamins. 2-Methylnaphthoquinone is a more effective coagulant than vitamin K.
Other natural naphtoquinones include juglone, plumbagin, droserone.
Naphthoquinone derivatives have significant pharmacological properties. They are cytotoxic, they have significant antibacterial, antifungal, antiviral, insecticidal, anti-inflammatory, and antipyretic properties. Plants with naphthoquinone content are widely used in China and the countries of South America, where they are used to treat malignant and parasitic diseases.[5]
Naphthoquinone functions as a ligand (through the electrophilic C=C).[6]
See also
References
- ↑ Merck Index, 11th Edition, 6315.
- ↑ Gaultier, J.; Hauw, C. (1965). "Structure de l'α-Naphtoquinone". Acta Crystallographica 18 (2): 179–183. doi:10.1107/S0365110X65000439.
- ↑ 3.0 3.1 Grolig, J.; Wagner, R. (2005), "Naphthoquinones", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a17_067
- ↑ Braude, E. A.; Fawcett, J. S. (1953), "1,4-Naphthoquinone", Org. Synth. 33: 50; Coll. Vol. 4: 698
- ↑ Babula, P.; Adam, V.; Havel, L.; Kizek, R. (2007). "Naphthoquinones and their Pharmacological Properties". Ceská a Slovenská Farmacie (in Czech) 56 (3): 114–120. PMID 17867522.
- ↑ Kündig, E. P.; Lomberget, T.; Bragg, R.; Poulard, C.; Bernardinelli, G. (2004). "Desymmetrization of a meso-Diol Complex Derived from [Cr(CO)3(η6-5,8-Naphthoquinone)]: Use of New Diamine Acylation Catalysts". Chemical Communications 2004 (13): 1548–1549. doi:10.1039/b404006f.
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