It is used as a hydrogen acceptor and oxidant in organic synthesis. 1,4-Benzoquinone serves as a dehydrogenation reagent. It is also used as a dienophile in Diels Alder reactions. Benzoquinone is also used to suppress double-bond migration during olefin metathesis reactions.
p-Benzoquinone (“quinone”) is prepared by the oxidation of aniline with either potassium dichromate or manganese dioxide in sulphuric acid (p. 125) and is also readily obtained by oxidising hydroquinone, p-aminophenol or p-phenylene diamine.
It is used as a fungicide, as a reagent in photography, and to make dyes and other chemicals. * p-Benzoquinone is on the Hazardous Substance List because it is regulated by OSHA and cited by ACGIH, DOT, NIOSH, DEP, IARC, IRIS, NFPA and EPA.