Tricyclic heteroaromatic systems. Synthesis and adenosine receptor binding evaluation of some pyrazolo-quinoline and [1]benzopyrano-pyrazole derivatives

The title compounds were synthesized and tested for their ability to displace A1 and A2 adenosine specific radioligands on the basis of their similarity to CGS 8216, a potent benzodiazepine receptor ligand which also shows some adenosine receptor affinity. Some of the title compounds showed a greater inhibiting potency than the lead compound. None of them showed affinity for the A2 receptors meaning that, although they are weak ligands, they are at least specific for the A1 receptors.