To provide a compound that has the effect of inhibiting PDE9 and is useful as an active ingredient in a therapeutic and/or prophylactic agent for urine collection disorders, urination disorders, diseases of the bladder and urinary system, and the like. Investigating compounds that have the effect of inhibiting PDE9 and are useful as active ingredients in a therapeutic and/or prophylactic agent for urine collection disorders, urination disorders, diseases of the bladder and urinary system, and the like, the inventors of the present invention verified that an imidazoquinoxaline compound or a triazolo-quinoxaline compound has the effect of inhibiting PDE9, thereby completing the present invention. This imidazoquinoxaline compound or triazolo-quinoxaline compound has the effect of inhibiting PDE9 and can be used a therapeutic and/or prophylactic agent for urine collection disorders, urination disorders, diseases of the bladder and urinary system, and the like.本發明之課題在於提供一種有用之化合物，其係具有PDE9阻礙作用，且可用為蓄尿障礙、排尿障礙及膀胱‧尿路系疾病等之治療劑及/或預防劑的有效成分。本發明者們乃就具有PDE9阻礙作用，且可用為蓄尿障礙、排尿障礙及膀胱‧尿路系疾病等之治療劑及/或預防劑的有效成分之有用的化合物進行檢討，確認了咪唑并喹啉化合物或三唑并喹啉化合物具有PDE9阻礙作用，而完成了本發明。本發明之咪唑并喹啉化合物或三唑并喹啉化合物乃具有PDE9阻礙作用，且得以使用作為蓄尿障礙、排尿障礙及膀胱‧尿路系疾病等之預防及/或治療劑。
