Novel Technologies Of Preparing 1-aminoanthraquinone From 1-nitroanthraquinone

1-aminoanthraquinone is one of important intermediates of anthraquinone dyes, which is widely used and heavy demanded in the dyestuff market. The traditional synthetic methods are complex process, high pollution and low purity of 1-aminoanthraquinone. Many efforts have been made in recent years, however, they have no industrial value for high-level equipment must be used with high cost. In this paper, we aim to develop novel preparation technologies which are green, high efficiency, simple process, low cost and high purity based on the existing methods to solve the problems above.In the first part of this paper, we choose solvent and nucleophilic reagent of the reaction. Then we establish the synthetic method that 1-nitroqnthraquinone is choosed as raw material, urea as nucleophilic reagent and N-methylpyrrolidinone as reaction solvent to synthesis 1-aminoanthraquinone. The optimization condition is confirmed by a series of experiments. The optimization condition is 1-nitroanthraquinone:5.06 g (0.02 mol); urea:7.2 g (0.12 mol); N-methylpyrrolidinone:60 mL; T:160 ℃; t:12 h. The purity of 1-aminoanthraquinone is 81.2% and the yield is 98% under the optimization condition. We also investigate the effects of adding methods of water and urea on the reaction.In the second part of this paper, we choose oil of vitriol as the reaction medium, ammonium molybdate as the catalyst to prepare 1-aminoanthraquinone by reducing 1-nitro-anthraquinone with iron powder, while iron powder is oxidized to form ferrous sulfate. This method does not produce iron mud which is harm for environment and we can carry the next step directly in the medium of oil of vitriol. The optimization condition is confirmed by a series of experiments. The optimization condition is 1-nitroanthraquinone:5.06 g (0.02 mol); iron powder:3.96 g (0.07mol); ammonium molybdate:0.5 g (0.0004mol); 85% sulfuric acid: 25 mL; T:90 ℃; t:4 h. The purity of 1-aminoanthraquinone is 95.1% and the yield is 96%. We can carry out bromination directly in the medium of reductive reaction by adding bromine and the yield of 1-amino-2,4-dibromanthraquinone is 84%.