Sulfuric Acid → Quinacridone

Participants

Reaction Steps

10 Parts of the 6,13-dihydroquinacridone obtained in Example 9 and 80 parts of methanol were charged into a 200-ml flask having a refluxer, and stirred. 12 Parts of a 50% NaOH aqueous solution was added, and the mixture was stirred at 40° C. for 30 minutes to form a salt. 26 Parts of 10% sulfuric acid was added dropwise to hydrolyze the salt, and the reaction mixture was refluxed under heat for 1 hour. 10 Parts of sodium m-nitrobenzenesulfonate was added, and immediately therafter, 50 parts of a 50% NaOH aqeuous solution was added. Then, the mixture was refluxed for 4 hours to give 9.88 parts (99.4% of the theoretical yield) of an unsubstituted quinacridone having an excellent particle diameter as a pigment.

Provenance & Evidence