The present invention provides compounds of the formula wherein R1 and R2 have meaning as defined herein in the specification. The compounds of formula (I) are adenosine A2A receptor antagonists and, thus, may be employed for the treatment of conditions and diseases mediated by the adenosine A2A receptor activity. Such conditions include, but are not limited to, diseases of the central nervous system such as depression, cognitive function diseases and neurodegenerative diseases such as Parkinson's disease, senile dementia as in Alzheimer's disease or psychoses and stroke. The compounds of the present invention may also be employed for the treatment of attention related disorders such as attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD), extra pyramidal syndrome, e.g., dystonia, akathisia, pseudoparkinsonism and tardive dyskinesia, and disorders of abnormal movement such as restless leg syndrome (RLS) and periodic limb movement in sleep (PLMS); cirrhosis, and fibrosis and fatty liver; dermal fibrosis in diseases such as scleroderma; and the mitigation of addictive behavior. In particular, the compounds of the present invention may be employed to improve motor-impairment due to neurodegenerative diseases such as Parkinson's disease.