PROBLEM TO BE SOLVED: To provide a heterocyclic derivative which exhibits powerful IAP antagonistic activity.SOLUTION: A compound expressed by a formula or its salt is provided. In the formula, R1 and R4 are the same or different and denote a hydrogen atom or 1 to 6C alkyl which may have a substituent, R2 denotes 1 to 6C alkyl which may have a substituent, R3 and R5 are the same or different and denote a cyclic group which may have a substituent or 1 to 6C alkyl which may have a substituent, and a ring A denotes a heterocyclic ring which may have a substituent.COPYRIGHT: (C)2012,JPO&INPIT【課題】強力なIAP拮抗活性を示す複素環誘導体を提供すること。【解決手段】式[式中、各記号は本明細書中で定義した通りである。]で表される化合物またはその塩。【選択図】なし
