6-(2-Furanyl)-9H-purin-2-amine derivatives as A2A adenosine antagonists

Structure–activity relationships have been investigated through substitutions at the 9-position of the 2-amino-6-(2-furanyl) purine (5) to identify novel and selective A2A adenosine receptor antagonists. Several potent and selective antagonists were identified. In particular, compounds 20, 25, and 26 show very high affinity with excellent selectivity.