Sulfuric Acid → Quinacridone

Participants

Reaction Conditions

Reaction Steps

A 200-ml flask was charged with 6.96 parts of the 2,5-dianilinoterephthalic acid obtained in Example 29 and 70 parts of sulfuric acid having a concentration of 98%, and while the mixture was stirred, the mixture was maintained at 160° C. for 5 hours. Then, the mixture was cooled to 80° C. or lower, and 50 parts of water was gradually added over 4 hours. Then, the mixture was poured into 500 parts of ice-containing water at one stroke, and the mixture was filtered, washed with water and dried to give 5.83 parts (93.5% of the theoretical yield) of an unsubstituted quinacridone.

Provenance & Evidence