PROBLEM TO BE SOLVED: To provide a compound useful as a novel antitumor agent targeting CSCs likely to be critically involved in persistent proliferation of a malignant tumor and cancer metastasis, recurrence and resistance to an antitumor agent.SOLUTION: The invention provides a compound represented by formula (I) or a pharmaceutically acceptable salt thereof. [In the formula, Ra represents fluorine or the like; n represents a number from 1 to 4; R1 and R2 each represent a hydrogen atom or the like; L represents a bond or the like; V represents a C1-6 alkylene or the like; and Q represents a C6-10 aryl or the like.]SELECTED DRAWING: NoneCOPYRIGHT: (C)2020,JPO&INPIT【課題】悪性腫瘍の持続的増殖、がんの転移、再発及び抗腫瘍剤への耐性に重要な関与が示唆されるCSCを標的とする、新規抗腫瘍剤として有用な化合物を提供する。【解決手段】式(I)で表される化合物又はその製薬学的に許容される塩。[式中、Raは、フッ素等を表し、nは、1~4を表し、R1及びR2は、水素原子等を表し、Lは、結合等を表し、Vは、C1-6アルキレン等を表し、Qは、C6-10アリール等を表す]【選択図】なし