| abstract |
A pyrazine derivative of the following formula (1) wherein R 1 is hydrogen or optionally substituted lower alkyl; X is hydrogen, halogen, hydroxy, cyano, or amino, aryl, heterocyclic group or the like; Y is hydrogen, halogen, hydroxy, acyl, amino or the like and Z is aryl or heteroaryl, each of which is optionally substituted; or one of its salts. The pyrazine compound (1) and one of its pharmaceutically acceptable salts are adenosine antagonists and are useful for the prevention and / or treatment of depression, dementia (for example, Alzheimer's disease, cerebrovascular dementia (for example stroke, etc. ), heart failure and the like. |