The present invention addresses the issue of providing: a compound exhibiting excellent medicinal efficacy as an anti-adenovirus agent； and an anti-adenovirus agent. The present invention provides a compound indicated by general formula [1] or a salt thereof (in the formula: R1 indicates a halogen atom, a substitutable amino group, a substitutable C1-6 alkoxy group or a protectable hydroxyl group, etc.； R2 indicates a hydrogen atom or an amino protecting group； R3 indicates a substitutable C1-20 alkoxy group, a substitutable aryloxy group, or a substitutable amino group, etc.； and R4 indicates a substitutable C1-20 alkoxy group, a substitutable aryloxy group, or a substitutable amino group, etc.).本發明的課題為提供一種作為抗腺病毒劑顯示優異的藥效之化合物及抗腺病毒劑。本發明提供一種化合物或其鹽，其由通式[1](式中，R1表示鹵素原子、可以經取代之胺基、可以經取代之C1-6烷氧基或可以經保護之羥基等；R2表示氫原子或胺保護基；R3表示可以經取代之C1-20烷氧基、可以經取代之芳氧基或可以經取代之胺基等；R4表示可以經取代之C1-20烷氧基、可以經取代之芳氧基或可以經取代之胺基等。)表示。
