Study on the Synthesis of 1,4-Dimethyl Anthraquinone

2-(2′,5′-dimethylbenzoyl) benzoic acid was synthesized by Friedel-crafts acylation from phthalic anhydride and p-xylene in the presence of AlCl3 and DMAC.The catalyst,a raw material mole of ratio,the solvent and the reaction temperature has carried on the optimized choice. 2-(2′,5′-dimethylbenzoyl) benzoic acid separately carries on dehydration with gathers the phosphoric acid,the strong sulfuric acid,the fuming sulfuric acid and so on to synthesize 1,4-dimethyl anthraquinones.The results show that the process using fuming sulfuric acid was better.The reaction medium was 1,2-dichoroethane,reaction temperature was 60 ℃,reaction time was 2.5 h,the yield was 88.63%.The chemical structure was characterized by FT-IR and 1 H-NMR.