1-Nitroanthraquinone → 1-Aminoanthraquinone

Participants

Reaction Conditions

Reaction Steps

15 Parts of the nitroanthraquinone (1-nitroanthraquinone content: 74.3%) used in Example 1 was sufficiently pulverized and suspended in 279 parts of water at room temperature. Upon addition thereto of 30.7 parts of a 30.5% sodium hydrosulfide aqueous solution, there was generated a slight amount of heat and the solution color was turned into green. In the course of temperature rise to 95° C. for the period of 30 minutes, the reaction mixture became very viscous but the temperature rise was continued. During additional 4-hour agitation at 95°-98° C., there took place little advancement of the reduction reaction. The reaction mixture was cooled to 70° C., filtered, washed and dried to obtain 12.5 parts of an aminoanthraquinone containing 75.6% of 1-aminoanthraquinone. The obtained aminoanthraquinone crystals had the maximum length of 3-5μ, and a photograph thereof is shown in FIG. 3. The yield of 1-aminoanthraquinone as calculated in terms of purity was 96.2%. The amount of water used for the reaction was 20 times that of the nitroanthraquinone, but since the reaction mixture becomes too viscous in the course of temperature rise, it was difficult to lessen the water amount below such level. Also, the filtering rate was very low because of small size of crystals and there was required about 10 times as much time for filtration as required in Example 1.

Provenance & Evidence