abstract |
Quinoline derivatives and quinazoline derivatives of formula (Ia) and pharmaceutically acceptable salts or solvates thereof, which have a strong antitumor activity, are disclosed, wherein: X represents CH or nitrogen; R15 and R16 represent C1-6alkoxy; R17, R18, R19 and R20 are as defined in the specification; and R21 represents optionally substituted azolyl as defined in the specification. |