Anthraquinone is a derivative of anthracene.
Physical properties
Anthraquinone melts at 286°C, boils at 379.8°C.
It is insoluble in water or alcohol, but dissolves in nitrobenzene and aniline.
Obtaining anthraquinone
There are several ways to obtain anthraquinone:
- Oxidation of anthracene
- Condensation of benzene with phthalic anhydride in presence of AlCl3 (Friedel-Crafts substitution). The resulting o-benzoylbenzoic acid then undergoes cyclization, forming anthraquinone.
- Diels-Alder reaction (from naphtoquinone and a 1,3-diene)
Industrial applications
Anthraquinone is used in production of dyes, such as alizarin.
Many natural pigments are derivatives of anthraquinone.