Study On The Synthesis Of1-nitroanthraquinone By Green Nitrations

1-nitroanthraquinone is one of the most important anthraquinone derivatives. It is widely applied in the synthesis of drugs, dyes and other functional fine chemicals, mainly for producing1-aminoanthraquinone and1-amino-4-bromoanthraquinone-2-sulfonic acid. The traditional synthesis of1-nitroanthraquinone is nitration of anthraquinone by mixing acid (nitric acid plus sulfuric acid). Unfortunately, this mothed has some drawbacks such as formation of extremely bulky waste water and low selectivity.The nitration based on nitrogen oxides can avoid the use of sulfuric acid, which promises the formation of extremely bulky waste acidic water. Kyodai nitration and N2O5-based nitration are the two promising methods.1-nitroanthraquinone was prepared from anthraquinone by direct nitration with N2O4-O3. Some effect factors were discussed, such as catalysts, N2O4dosage, O3flowing rate and reaction time. Under the optimal reaction conditions,1-nitroanthraquinone could be obtained in a high yield of82%when3equivalent N2O4and0.6L·min-1flowing rate of O3were used and the reaction was carried out in100mL dichloroethane at-20℃for5h in the presence of methylsulfonic acid. The conversion of anthraquinone is95%.1-nitroanthraquinone was also synthesized from anthraquinone by nitration with N2O5in halogenated alkanes. Some factors such as catalyst, loading amount of N2O5, reaction temperature, reaction time and the quantity of solvent were discussed. The results showed that1-nitroanthraquinone could be obtained in a high yield of90%when1.45equivalent N2O5was used and the nitration was carried out at0℃for1h in the presence of methylsulfonic acid. The conversion of anthraquinone is quantitative.Two atom-economical and clean nitration methods for the synthesis of1-nitroanthraquinone were investigated in this dissertation and the results provide useful basis for industrial-scale production.