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. 40 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 the mixture was refluxed for 4 hours to give 9.41 parts (94.7% of the theoretical yield) of an unsubstituted quinacridone. The quinacridone was measured for a purity by IR and absorbance to show 91.2% of quinacridone and 8.8% of 6,13-dihydroquinacridone.

Provenance & Evidence