2,5-Di-p-toluidinoterephthalic acid → 5,12-Dihydro-2,9-dimethylquino(2,3-b)acridine-7,14-dione

Participants

Reaction Conditions

Reaction Steps

To 150.0 g of polyphosphoric acid (118%) was added with stirring 30.0 g (79.7 mmol) of 2,5-bis(p-toluidino)terephthalic acid. The stirred mixture was irradiated in the microwave oven for 2.5 minutes. After the reaction mixture was cooled to 130° C., 250 g of water was slowly added with stirring. The resultant slurry was stirred for 30 minutes, after which the solid component was collected by filtration and washed with 6.0 liters of water. The presscake was dried overnight in an oven at 60° C. to give 27.0 g of crude 2,9-dimethylquinacridone (C. I. Pigment Red 122) (100% yield).

Provenance & Evidence