129721-79-5 5,6,12,13-Tetrahydroquino(2,3-b)acridine-7,14-dione 5862-38-4 6,13-Dihydroquinacridone EINECS 227-508-7 Quino(2,3-b)acridine-7,14-dione, 5,6,12,13-tetrahydro-