Topoisomerase II-alpha inhibitors and methods of treating cancer using the same

A compound of formula:

• or a pharmaceutically acceptable salt, or solvate, thereof,
• wherein:
• R1 is —NR7CO—R8 or —CO—NR7—R8, wherein R7 is H or C1-C3 alkyl optionally substituted with one or more halogen, hydroxyl, or C1-C3 alkoxy and R8 is H, or alkyl, or cycloalkyl both optionally substituted with one or more halogen, hydroxyl, C1-C3 alkyl, C1-C3 alkoxy, or heterocyclic optionally substituted with one or more oxo (═O), halogen, hydroxyl, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 acyl, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 hydroxyalkyl, or heterocyclic;
• R2, R3 and R5 are independently H, halogen, C1-C3 alkyl or OR9, wherein R9 is H or C1-C3 alkyl, where the C1-C3 alkyls are optionally substituted with one or more halogen, hydroxyl, C1-C3 alkoxy or C1-C3 hydroxyalkyl;
• R4 is aryl or heteroaryl, which are optionally substituted with one or more halogen, hydroxyl, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 acyl, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 hydroxyalkyl, or heterocyclic;
• and
• R6 is H, —COOR11, or —CONR12R13, wherein R11, R12, and R13 are independently alkyl or cycloalkyl each optionally substituted with one or more halogen, hydroxyl, C1-C3 alkyl, C1-C3 alkoxy, or heterocyclic which in turn is optionally substituted with one or more halogen, hydroxyl, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 acyl, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 hydroxyalkyl, or heterocyclic, or aryl or heterocyclic optionally substituted with one or more halogen, hydroxyl, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 acyl, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 hydroxyalkyl, or heterocyclic.