Hydrogen Peroxide → Quinacridone

Participants

Reaction Conditions

Reaction Steps

A one liter flask equipped with a thermometer, stirrer and condenser was charged with 40 grams 6,13-dihydroquinacridone, 185 ml methanol, 42 grams 50% aqueous sodium hydroxide and 1.2 grams of the barbituric acid methyl dihydro-quinacridone additive prepared according to Example 3. The mixture was stirred under a slow flow of nitrogen at 50 to 55° C. for one hour. 0.5 gram anthraquinone mono sulfonic acid sodium salt, as catalyst, was added and the reaction mixture was heated to reflux. 67 grams of an aqueous 19.3% hydrogen peroxide solution were added into the reaction mixture with a peristaltic pump at a pumping rate of 0.3 ml/minute while maintaining reflux and a slow nitrogen flow. The resulting violet suspension was further stirred for 10 minutes at reflux, then diluted with 100 ml cold water and filtered. The presscake was washed with hot water then dried, yielding 38.9 grams violet reddish quinacridone.

Provenance & Evidence