PROBLEM TO BE SOLVED: To provide pyrazolopyrimidine derivatives that inhibit the FGF (fibroblast growth factor) receptors, and a process for preparing them.SOLUTION: The invention relates to FGF-inhibiting pyrazolopyrimidine derivatives of general formula (I).SELECTED DRAWING: None【課題】FGF(線維芽細胞成長因子)受容体を阻害するピラゾロピリミジン誘導体、これらの調製方法の提供。【解決手段】一般式(I)のFGF阻害ピラゾロピリミジン誘導体。【選択図】なし