The present invention relates to compounds of the general formula (I): wherein R is phenyl, pyridin-2-yl, -C(O)-O-lower alkyl, -C(O)-lower alkyl, -C(O)-morpholinyl, -C(O)-NR'2,-(CH2)N-NR'2or -(CH2)N-O-lower alkyl and R' may be hydrogen or lower alkyl; and to pharmaceutically acceptable acid addition salts thereof. The compounds disclosed in this application have a good affinity to the A2A receptor and therefore they may be used in the control or prevention of illnesses based on the modulation of the adenosine system, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, neuroprotection, schizophrenia, anxiety, pain, respiration deficits, depression, drug addiction, such as amphetamine, cocaine, opioids, ethanol, nicotine, cannabinoids, or against asthma, allergic responses, hypoxia, ischaemia, seizure and substance abuse. Furthermore, compounds of the present invention may be useful as sedatives, muscle relaxants, antipsychotics, antiepileptics, anticonvulsants and cardiaprotective agents for disorders such as coronary artery disease and heart failure.