Compound 1 is a potent A(2A)/A(1) receptor antagonist in vitro (A(2A) K(i) = 4.1 nM; A(1) K(i) = 17.0 nM) that has excellent activity, after oral administration, across a number of animal models of Parkinson's disease including mouse and rat models of haloperidol-induced catalepsy, mouse model of reserpine-induced akinesia, rat 6-hydroxydopamine (6-OHDA) lesion model of drug-induced rotation, and MPTP-treated non-human primate model.