The purpose of the present invention is to prevent or treat hyperphosphatemia or disease associated with hyperphosphatemia. To fulfill this purpose, a compound having general formula (I), or a pharmaceutically acceptable salt thereof, is provided. [In the formula, R1 represents a hydrogen atom, etc., R2 represents a hydrogen atom, etc., A represents a single bond, etc., E represents a benzene ring, etc., G represents a hydrogen atom, etc., X represents CH, etc., and Y represents -C(=O)-, etc].本發明之課題係預防或治療高血磷症、或與高血磷症相關連的疾病。解決手段係具有通式(I)之化合物或其藥理容許鹽。[式中，R1：表示氫原子等、R2：表示氫原子等、A：表示單鍵等、E：表示苯環等、G：表示氫原子等、X：表示CH等、Y：表示-C(=O)-等。]
