Synthesis and SAR studies of trisubstituted purinones as potent and selective adenosine A2A receptor antagonists

A series of trisubstituted purinones was synthesized and evaluated as A(2A) receptor antagonists. The A2A structure-activity relationships at the three substituted positions were studied and selectivity against the A(1) receptor was investigated. One antagonist 12o exhibits a K-i of 9 nM in an A(2A) binding assay, a K-b of 18 nM in an A2A cAMP functional assay, and is 220-fold selective over the A1 receptor. (C) 2009 Elsevier Ltd. All rights reserved.