Pyrimidine derivatives and their use as Pi3k inhibitors

And it has a superior PI3K inhibitory effect, since it is excellent in stability and water solubility in the body, providing a useful drug as a preventive or therapeutic agent for cancer. Of formula (I): [Wherein, X represents a single bond, etc.; Y is a single bond such as (but, X and Y are not a single bond at the same time); Z is a hydrogen atom or the like; m is an integer of 1 or 2 ; Compounds represented by, or a pharmaceutically acceptable salt.