This invention relates to compounds of formula I
1
wherein
R
1
and R
2
are defined herein, or a pharmaceutically acceptable salt thereof.
It has been found that the compounds of formula I are adenosine receptor ligands with good affinity to the A
2A
-receptor and a high selectivity to the A
1
- and A
3
receptors. These compounds are useful, inter alia, in treatment of Alzheimer's disease, depression, Parkinson's disease and ADHD.