Quinone is an aromatic organic compound that contains a benzene ring in which two hydrogen atoms have been replaced by oxygen atoms.

 

Paraquinone (1,4-benzoquinone, O=C₆H₄=O) is a yellow crystalline solid obtained by the oxidation of aniline with chromic acid; it is used in the manufacture of hydroquinone for photographic developers.

 

Anthraquinone is a yellow crystalline quinone made from anthracene or by condensation of benzene and pthalic anhydride (see acid anhydride). It is the parent of numerous dyes of all colors, which are bright, fast, and suitable for synthetic fibers; they included alizarin and cochineal.