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.