Synthesis of Some Tricyclic Heteroaromatic Systems and Their A1 and A2a Adenosine Binding Activity.

Summary The syntheses, A1 and A2a adenosine receptor affinities and structure-activity relationships of some 2-aryl-1,2,4-tri-azolo [1,5-a]quinoxalines, 2-arylimidazo[1,2-a]quinoxalines, 1-arylimidazo[1,5-a]quinoxalines are reported and compared with that of a previously reported 2-phenylpyrazolo[ 1,5-a]quinoxaline. The results show that some triazoloquinoxalines are potent and specific A, adenosine receptor ligands and that the replacement of either nitrogen at position 1 or 3 of the triazoloquinoxaline moiety with a CH brought about a decrease in affinity at both adenosine receptors.