Online Encyclopedia
Make a correction
Your email address will not appear on the site. Note, comments may take some time to be approved.
Back to article:
QUINONES
Your email:
Article name:
Article content:
QUINONES, in organic chemistry, a group of compounds in which two hydrogen atoms of a benzene nucleus are replaced by two oxygen atoms. This replacement may take place either in the ortho or para positions, giving rise to orthoquinones or to paraquinones; metaquinones do not appear to have been isolated. The para or true quinones are obtained by the oxidation of hydrocarbons with chromic acid or of various para di-derivatives of benzene with chromic acid mixture, such, for example, as para-aminophenol, para-phenylene diamine, paraaminoazobenzene, &c. H. v. Pechmann (Ber., 1888, 21, p. 1417) has shown that a-diketones are converted into paraquinones by the action of warm solutions of the caustic alkalis, diacetyl yielding para-xyloquinone: