Abstract

p-Benzoquinone or quinone was discovered in 1838 as a product of the action of manganese dioxide in sulfuric acid on the natural product, quinic acid, However, benzoquinones generally prepared by the oxidation of disubstituted aromatic hydrocarbons derivatives having hydroxyl or amino groups in the ortho and para positions. The quinone results from the oxidation of hydroquinone, p-aminophenol, or p-phenylendiamine. Certain quinones are obtainable in moderate or fair yield by oxidation of starting materials containing only one hydroxyl or amino group as exemplified by the industrial production of quinine from aniline. Oxidation of phenols and amines constitutes the chief topic of discussion in this chapter.