1,4-Naphthoquinone: Difference between revisions

| Verifiedfields = changed

| verifiedrevid = 414651852

| Reference =<ref>''Merck Index'', 11th Edition, '''6315'''.</ref>

| Name = Naphthoquinone

| ImageFile = 1,4-Naphthoquinone.svg

| ImageSize = 130

| ImageFile1 = 1,4-Naphthoquinone-3D-balls.png

| ImageSize1 = 180

| ImageName1 = Ball-and-stick model

| PIN = Naphthalene-1,4-dione <!-- Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) -->

| OtherNames = 1,4-Naphthoquinone<br />Naphthoquinone<br />α-Naphthoquinone

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = RBF5ZU7R7K

| ChEMBL_Ref = {{ebicite|changed|EBI}}

| ChEMBL = 55934

| PubChem = 8530

| ChemSpiderID = 8215

| InChI = 1/C10H6O2/c11-9-5-6-10(12)8-4-2-1-3-7(8)9/h1-6H

| InChIKey = FRASJONUBLZVQX-UHFFFAOYAK

| StdInChI = 1S/C10H6O2/c11-9-5-6-10(12)8-4-2-1-3-7(8)9/h1-6H

| StdInChIKey = FRASJONUBLZVQX-UHFFFAOYSA-N

| SMILES = O=C1c2ccccc2C(=O)cc1

|Section2={{Chembox Properties

| Formula = C{{sub|10}}H{{sub|6}}O{{sub|2}}

| MolarMass = 158.15 g/mol

| Density = 1.422 g/cm{{sup|3}}

| MeltingPtC = 126

| MeltingPt_notes =

| BoilingPt = Begins to sublime at 100 °C

| Solubility = 0.09 g/L

| MagSus = -73.5·10{{sup|−6}} cm{{sup|3}}/mol

'''1,4-Naphthoquinone''' or '''para-naphthoquinone''' is a [[quinone]] derived from [[naphthalene]]. It forms volatile yellow triclinic crystals and has a sharp odor similar to [[1,4-Benzoquinone|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.<ref>{{ cite journal |author1=Gaultier, J. |author2=Hauw, C. | title = Structure de l'α-Naphtoquinone | journal = Acta Crystallographica | year = 1965 | volume = 18 | issue = 2 | pages = 179–183 | doi = 10.1107/S0365110X65000439 |bibcode=1965AcCry..18..179G }}</ref> It is an [[isomer]] of [[1,2-Naphthoquinone|1,2-naphthoquinone]].

==Preparation==

The industrial synthesis involves aerobic oxidation of naphthalene over a vanadium oxide catalyst:<ref name=Ullmann>{{ Ullmann | author = Grolig, J. | author2 = Wagner, R. | title = Naphthoquinones | doi = 10.1002/14356007.a17_067 }}</ref>

:C{{sub|10}}H{{sub|8}} + 3/2 O{{sub|2}} → C{{sub|10}}H{{sub|6}}O{{sub|2}} + H{{sub|2}}O

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]].<ref>{{ OrgSynth | author = Braude, E. A. | author2 = Fawcett, J. S. | year = 1953 | title = 1,4-Naphthoquinone | volume = 33 | pages = 50 | collvol = 4 | collvolpages = 698 | prep = CV4P0698 | url = http://www.orgsyn.org/orgsyn/pdfs/CV4P0698.pdf }}</ref>

==Reactions==

1,4-Naphthoquinone acts as strong [[dienophile]] in [[Diels-Alder reaction]]. Its adduct with [[1,3-butadiene]] can be prepared by two methods: 1) long (45 days) exposure of naphthoquinone in neat liquid butadiene taken in huge excess at room temperature in a thick-wall glass tube or 2) fast catalyzed [[cycloaddition]] at low temperature in the presence of 1 equivalent of [[tin(IV) chloride]]:<ref>{{ cite journal | author = M.A. Filatov | author2 = S. Baluschev | author3 = I.Z. Ilieva| author4 = V. Enkelmann | author5 = T. Miteva| author6 = K. Landfester | author7 = S.E. Aleshchenkov | author8 = A.V. Cheprakov | title = Tetraaryltetraanthra[2,3]porphyrins: Synthesis, Structure, and Optical Properties | journal = J. Org. Chem. | year = 2012 | volume = 77 | issue = 24 | pages = 11119–11131 | doi = 10.1021/jo302135q | pmid = 23205621 }}</ref>

[[File:Naphthoquinone reaction with butadiene.tif|center|400 px|Diels-Alder reaction of 1,4-naphthoquinone with 1,3-butadiene]]

==Uses==

1,4-Naphthoquinone is mainly used as a precursor to [[anthraquinone]] by reaction with butadiene followed by oxidation. Nitration gives 5-nitro-1,4-naphthalenedione, precursor to an {{Not a typo|aminoanthroquinone}} that is used as a dye precursor.<ref name=Ullmann/>

==Derivatives==

Naphthoquinone forms the central chemical structure of many natural compounds, most notably the [[vitamin K|K vitamins]]. 2-Methyl-1,4-naphthoquinone, called [[menadione]], is a more effective coagulant than vitamin K.

Other natural naphthoquinones include [[juglone]], [[plumbagin]], [[Droseraceae|droserone]].

Naphthoquinone [[derivative (chemistry)|derivatives]] have significant pharmacological properties. They are [[cytotoxic]], they have significant [[antibacterial]], [[Antifungal medication|antifungal]], [[Antiviral drug|antiviral]], [[Insecticide|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.<ref>{{ cite journal | last1 = Babula | first1 = P. | last2 = Adam | first2 = V. | last3 = Havel | first3 = L. | last4 = Kizek | first4 = R. |title = Naphthoquinones and their Pharmacological Properties | language = Czech | journal = Ceská a Slovenská Farmacie | year = 2007 | volume = 56 | issue = 3 | pages = 114–120 | pmid = 17867522 }}</ref>

Naphthoquinone functions as a ligand through its electrophilic carbon-carbon double bonds.<ref>{{ cite journal |author1=Kündig, E. P. |author2=Lomberget, T. |author3=Bragg, R. |author4=Poulard, C. |author5=Bernardinelli, G. | title = Desymmetrization of a ''meso''-Diol Complex Derived from <nowiki>[</nowiki>Cr(CO){{sub|3}}(η{{sup|6}}-5,8-Naphthoquinone)<nowiki>]</nowiki>: Use of New Diamine Acylation Catalysts | journal = Chemical Communications | year = 2004 | volume = 2004 | issue = 13 | pages = 1548–1549 | doi = 10.1039/b404006f |pmid=15216374 }}</ref>

[[Dichlone]], a chlorinated derivative of 1,4-naphthoquinone, is used as a fungicide.

*[[Hooker reaction]]

{{reflist}}

{{DEFAULTSORT:Naphthoquinone, 1, 4-}}

[[Category:1,4-Naphthoquinones]]