Patent ID: 8314250

Claim:
A compound according to formula 1, wherein the compound exhibits cytotoxic activity and: R 2 is hydrogen or dimethylamino; R 3 is hydrogen; R 4 is cycloalkyl optionally substituted with alkyl, or benzyl optionally substituted with halogen; or R 3 and R 4 , together with the nitrogen atom to which they are attached, form piperidinyl substituted with one or more substituents independently selected from the group consisting of: hydroxyl and phenyl optionally substituted with halogen; R 5 is alkyl or benzyl optionally substituted with halogen; and R 6 is benzodioxolyl or phenyl optionally substituted with one to three substituents independently selected from the group consisting of: halogen, hydroxyl, alkoxy optionally substituted with halogen, alkyl, phenoxy optionally substituted with halogen, cyano, or alkyl, and phenyl optionally substituted with alkyl or halogen; or a pharmaceutically-acceptable salt thereof.