申请人:Mitsui Toatsu Chemicals, Incorporated
公开号:US03959318A1
公开(公告)日:1976-05-25
Highly pure 5-nitro-1,4,4a,9a-tetrahydroanthraquinone can be obtained by subjecting 6-nitronaphthoquinone-containing crude 5-nitro-1,4-naphthoquinone to Diels-Alder condensation reaction with 1,3-butadiene in a solvent including benzene, an alkylated aromatic hydrocarbon such as toluene, xylene or the like, a halogenated aromatic hydrocarbon such as chlorobenzene, dichlorobenzene, or the like, or a halogenated aliphathic hydrocarbon such as trichloroethylene, perchloroethylene or the like, cooling the resulting reaction solution to crystallize the reaction product, and separating the thus crystallized product by filtration. 5-nitro-1,4,4a,9a-tetrahydroanthraquinone has a relatively small solubility in the above-mentioned solvents, while the solubility of 6-nitro-1,4,4a,9a-tetrahydroanthraquinone in the solvents is rather great, thus the above-mentioned solvents being effective for the separation of these compounds from each other. The oxidation and the subsequent reduction of the thus obtained 5-nitro-1,4,4a,9a-tetrahydroanthraquinone yields 1-aminoanthraquinone with a purity above 98 wt% and a 2-aminoanthraquinone content below 1 wt%. The above-mentioned solvents are also effective for purification of 6-nitro-1,4,4a,9a-tetrahydroanthraquinone-containing 5-nitro-1,4,4a,9a-tetrahydroanthraquinone by recrystallization.
通过将含有6-硝基萘醌的粗5-硝基-1,4-萘醌与1,3-丁二烯在溶剂中进行Diels-Alder缩合反应得到高纯度的5-硝基-1,4,4a,9a-四氢蒽醌。该溶剂包括苯、烷基化芳香烃如甲苯、二甲苯或类似物、卤代芳香烃如氯苯、二氯苯或类似物或卤代脂肪烃如三氯乙烯、四氯乙烯或类似物,将反应产物的溶液冷却结晶,通过过滤分离晶化的产物。5-硝基-1,4,4a,9a-四氢蒽醌在上述溶剂中的溶解度相对较小,而6-硝基-1,4,4a,9a-四氢蒽醌在这些溶剂中的溶解度相当大,因此这些溶剂对于从彼此分离这些化合物非常有效。因此获得的5-硝基-1,4,4a,9a-四氢蒽醌的氧化和随后的还原产生纯度高于98wt%且2-氨基蒽醌含量低于1wt%的1-氨基蒽醌。上述溶剂对于通过重结晶纯化含有6-硝基-1,4,4a,9a-四氢蒽醌的5-硝基-1,4,4a,9a-四氢蒽醌也非常有效。