| abstract |
PROBLEM TO BE SOLVED: To provide an antitumor agent useful as a medicine. The following general formula (Wherein ----- means the presence or absence of a single bond, X means N or C—Rx, where Rx means a hydrogen atom or a halogen atom, R 1 and R 2 Means the same or different hydrogen atoms or halogen atoms, R 3 means a hydrogen atom or a carboxyl group, R 4 means an oxo group or a hydroxyl group, and R 5 means a hydrogen atom or an amino group. , R 6 represents a substituent such as cyclic amino)). [Selection] Figure 1 |