(E)-1-(Heterocyclyl or cyclohexyl)-2-[1,3,7-trisubstituted (xanthin-8-yl)] ethenes as A2a adenosine receptor antagonists

Abstract Some 1,3,7-trisubstituted-8-styrylxanthine analogues, with the aryl group replaced by a heterocycle or cyclohexane ring, were prepared and evaluated for their interaction with the A 1 and A 2a adenosine receptors. The highest degree of activity was displayed by the 1,3-dipropyl-7-methyl-8-[2-(3-thienyl)ethenyl]xanthine 4cdi , which was found to be a potent and selective A 2a antagonist in binding assays ( K i = 19 nM, A 1 /A 2a ratio = 30).