11a1b1a1b2568873213a13a13d13e13d13e4Disclosed is a pyrazolopyrimidine derivative represented by formula (I) a pharmaceutically acceptable salt thereof or the like which is useful as a prophylactic and/or therapeutic agent for skin diseases. (In the formula R represents NRR (wherein R and R may be the same or different and each represents a hydrogen atom an aralkyl group or the like) or the like R represents a group represented by formula (Ya) (wherein k and m each represents an integer of 0 2 n represents an integer of 0 4 L represents a single bond or the like R represents a halogen or the like R represents an aryl or the like X represents CR (wherein R represents a hydrogen atom or the like) or the like and R represents a hydrogen atom or the like) or the like R represents SOR (wherein R represents a lower alkoxy NRC(=O)R (wherein R represents a hydrogen atom or the like and R represents a lower alkyl or the like) or the like) or the like and R represents a hydrogen atom or the like.)
