| 摘要 |
A compound of the formula (I): <CHEM> wherein R<2> is hydrogen etc.; R<3> is halogen etc.; R<3> is represented by the formula: <CHEM> etc. wherein R<4> is halogen etc.; and Y is -OH or -NHOH, its optically active substance, its prodrug, its pharmaceutically acceptable salt, or its solvate. |
