5,6-dimethyl-9-hydroxy-1-(4'-aminophenyl)-6H-pyrido[4,3-b]carbazole

9-methoxy-5-methyl-1-(4'-aminophenyl)-6H-pyrido[4,3-b]carbazole

5,6-Dimethyl-1-(4-nitro-phenyl)-6H-pyrido[4,3-b]carbazol-9-ol

5,6-dimethyl-9-methoxy-1-[4'-(3-methylsulfamoyl)phenyl]-6H-pyrido[4,3-b]carbazole