Water → Quino[2,3-b]acridine-7,14-dione, 2,9-dichloro-5,12-dihydro-

Participants

Reaction Conditions

Reaction Steps

To 200.0 g of polyphosphoric acid (118%) were added 30.0 g (71.7 mmol) of 2,5-bis(p-chloroanilino)terephthalic acid and 0.6 g of phthalimidomethylquinacridone. The stirred mixture was irradiated in the microwave oven for 2.0 minutes. The reaction mixture was cooled to 150° C. and drowned in 400 g of methanol with vigorous stirring. The resultant methanol suspension was maintained at reflux for one hour, cooled to 60° C., added to 800 g of water, and heated at 60° C. for 30 minutes. The solid component was collected by filtration and washed with 8.0 liters of water. The presscake was dried overnight in an oven at 60° C. to give 28.0 g of 2,9-dichloroquinacridone (C. I. Pigment Red 202).

Provenance & Evidence