1-Aminoanthraquinone of high purity is obtained either by catalytically hydrogenating 5-nitro-1,4,4a,9a-tetrahydroanthraquinone dissolved in a polar organic solvent such as methyl cellosolve (i.e., .beta.-hydroxyethyl methyl ether) in the presence of a hydrogenation catalyst such as palladium on carbon or Raney nickel and then treating the resultant hydrogenated product with a base such as sodium hydroxide or pyridine, or by catalytically hydrogenating the 5-nitro-1,4,4a,9a-tetrahydroanthraquinone in the presence of both the hydrogenation catalyst and the base. By the action of the base, the 5-nitro-1,4,4a,9a-tetrahydroanthraquinone nucleus releases hydrogen atoms and is converted to the anthraquinone nucleus, and the released hydrogen serves to reduce the nitro group. Where an excess of hydrogen is introduced into the reaction system for hydrogenation, 1-aminoanthraquinone is further reduced into a leuco type compound thereof which can easily be returned to 1-aminoanthraquinone by oxidation.
高纯度的1-
氨基
蒽醌可通过在极性有机溶剂中溶解5-硝基-1,4,4a,9a-四氢
蒽醌,并在存在氢化催化剂(如碳上的
钯或Raney
镍)的情况下催化氢化来获得,该溶剂可以是甲基赛洛醇(即β-羟乙基甲基醚)。然后,用碱(如
氢氧化钠或
吡啶)处理所得的氢化产物,或者在氢化催化剂和碱的共存下催化氢化5-硝基-1,4,4a,9a-四氢
蒽醌。通过碱的作用,5-硝基-1,4,4a,9a-四氢
蒽醌核释放氢原子,并转化为
蒽醌核,释放的氢用于还原硝基。如果在氢化反应系统中引入过量的氢,则1-
氨基
蒽醌将进一步还原为其亚甲基型化合物,可以通过氧化轻松地将其返回为1-
氨基
蒽醌。