2,9-Dimethylquinacridonequinone 2,9-Dimethylquino(2,3-b)acridine-6,7,13,14(5H,12H)-tetrone 5791-64-0 EINECS 227-328-9 Quino(2,3-b)acridine-6,7,13,14(5H,12H)-tetrone, 2,9-dimethyl-