PROBLEM TO BE SOLVED: To provide a new anti-HBV drug.SOLUTION: An anti-hepatitis B virus drug comprises a compound represented by the formula (B) in the figure, its salt, or a solvate of them. [In the formula, R represents Br.]SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】新たな抗HBV薬の提供。【解決手段】下記式(B)で示される化合物、その塩又はそれらの溶媒和物を含有する抗B型肝炎ウイルス薬。[式中、RはBrを表す。]【選択図】なし