Development of Solid Acid Catalysts in Anthraquinone Synthesis with Phthalic Anhydride and Benzene

Anthraquinone (AQ) was an important organic synthetic intermediate. Replacing the traditional liquid catalysts with solid acid catalysts would make the process environmentally benign. The development and prospective study of solid acid catalysts in AQ synthesis, such as silica-alumina, acid clays, metal oxides, molecular sieve, heteropoly acid and cation-exchange resin were reviewed in this paper.