A new series of 1,3-dipropyl-8-(1-phenylacetamide-1H-pyrazol-3-yl)-xanthine derivatives has been identified as potent A2B adenosine receptor antagonists. The products have been evaluated for their binding affinities for the human A2B, A1, A2A, and A3 adenosine receptors. N-(4-chloro-phenyl)-2-[3-(2,6-dioxo-1,3-dipropyl-2,3,6,7-tetrahydro-1H-purin-8-yl)-5-methyl-pyrazol-1-yl] (11c) showed a high affinity for the human A2B adenosine receptor Ki = 7 nM and good selectivity (A1, A2A, A3/A2B > 140). Synthesis and SAR of this novel class of compounds is presented herein.

Bioorganic & Medicinal Chemistry, Volume 16, Issue 5, 1 March 2008, Pages 2419-2430

http://dx.doi.org/10.1016/j.bmc.2007.11.058