There are provided compounds of the formula
or the pharmaceutically acceptable salts thereof, wherein X, Y, Z, V1, V2, R1, R2, R3, R4 and R5 are herein described. These compounds are useful as anticancer agents.
There are provided compounds of the formula
or the pharmaceutically acceptable salts thereof, wherein X, Y, Z, V3, V2, R1, R2, R3, R4 and R5 are as herein described, processes for obtaining said compounds and pharmaceutical preparations containing them. These compounds are useful as anticancer agents, in particular as agents in the treatment of solid tumors.