Hydrogen Peroxide → Quinacridone

Beteiligte Stoffe

Reaktionsschritte

A one liter flask equipped with a thermometer, stirrer and condenser is charged with 40 grams 6,13-dihydroquinacridone, 250 ml methanol and 52.8 grams 50% aqueous sodium hydroxide. The mixture is stirred under a slow flow of nitrogen at 50°-55° C. for one hour generating 6,13-dihydroquinacridone di-sodium salt. 0.8 grams anthraquinone-2-sulfonic acid sodium salt are added and the mixture is heated to reflux temperature. 73.5 grams of an aqueous 16.9% hydrogen peroxide solution are added into the reaction mixture with a peristaltic pump at a rate of 0.4 ml/minute maintaining reflux under a slow nitrogen flow over 2 hours and 35 minutes. The resulting reddish suspension is further stirred for 4 hours at reflux then filtered. The presscake is washed with methanol followed by hot water then dried, yielding 38.9 grams red quinacridone.

Herkunft & Nachweise