This invention provides a pyrazolopyrimidine compound having the HIF-PHD inhibitory effect. The pyrazolopyrimidine compound contains a pyrazolopyrimidine compound represented by formula (I) or a pharmaceutically acceptable salt thereof. wherein, represents 7-hydroxypyrazolo [4,3-d] pyrimidin-5-yl which may be substituted, X represents a single bond or straight-chain alkylene which may be substituted, and Z represents a hydrogen atom or the following formula (i), formula (ii) or formula (iii): Ring A and ring A’ each independently represents an aryl group which may be substituted, a heteroaryl group which may be substituted, an alicyclic hydrocarbon group which may be substituted or a non-aromatic heterocycle group which may be substituted.本發明提供一種具有HIF-PHD抑制作用之吡唑并嘧啶化合物。本發明之吡唑并嘧啶化合物係包含式(I)表示之吡唑并嘧啶化合物或其藥理學上容許之鹽。式中，表示可經取代之7-羥基吡唑并[4,3-d]嘧啶-5-基，X表示單鍵或可經取代之直鏈狀伸烷基，Z表示氫原子或下述式(i)、式(ii)或式(iii)：，環A及環A’各自獨立地表示可經取代之芳基、可經取代之雜芳基、可經取代之脂環式烴基或可經取代之非芳族雜環基。
