AI tools

1,4-Naphthoquinone

Chemical compound From Wikipedia, the free encyclopedia

1,4-Naphthoquinone

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 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] It is an isomer of 1,2-naphthoquinone.

Quick Facts Names, Identifiers ...
Naphthoquinone[1]
Thumb
Thumb
Ball-and-stick model
Names
Preferred IUPAC name
Naphthalene-1,4-dione
Other names
1,4-Naphthoquinone
Naphthoquinone
α-Naphthoquinone
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.004.526
UNII
  • InChI=1S/C10H6O2/c11-9-5-6-10(12)8-4-2-1-3-7(8)9/h1-6H
    Key: FRASJONUBLZVQX-UHFFFAOYSA-N
  • InChI=1/C10H6O2/c11-9-5-6-10(12)8-4-2-1-3-7(8)9/h1-6H
    Key: FRASJONUBLZVQX-UHFFFAOYAK
  • O=C1c2ccccc2C(=O)cc1
Properties
C10H6O2
Molar mass 158.15 g/mol
Density 1.422 g/cm3
Melting point 126 °C (259 °F; 399 K)
Boiling point Begins to sublime at 100 °C
0.09 g/L
-73.5·10−6 cm3/mol
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 ?)
Close

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]

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:[5]

Thumb
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 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-Methyl-1,4-naphthoquinone, called menadione, is a more effective coagulant than vitamin K.

Other natural naphthoquinones 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.[6]

Naphthoquinone functions as a ligand through its electrophilic carbon-carbon double bonds.[7]

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

See also

References

Wikiwand - on

Seamless Wikipedia browsing. On steroids.