Tricyclic Heteroaromatic Systems. Synthesis and A1 and A2a Adenosine Binding Activities of Some 1-Aryl-1,4-dihydro-3-methyl[1]benzopyrano[2,3-c]pyrazol-4-ones, 1-Aryl-4,9-dihydro-3-methyl-1H-pyrazolo[3,4-b]quinolin-4-ones, and 1-Aryl-1H-imidazo[4,5-b]quinoxalines

The syntheses and A1 and A2a adenosine binding activities of some new 1-aryl-1,4-dihydro-3-methyl[1]benzopyrano[2,3-c]pyrazol-4-ones, 1-aryl-4,9-dihydro-3-methyl-1H-pyrazolo[3,4-b]-quinolin-4-ones, and 1-aryl-1H-imidazo[4,5-b]quinoxalines are reported. Some compounds show A1 adenosine receptor affinity and selectivity. Structure-activity relationships on these new classes of adenosine receptor ligands are defined.