Design, Synthesis and Biological Evaluation of a Novel Series of Potent, Orally Active Adenosine A<SUB>1</SUB> Receptor Antagonists with High Blood-Brain Barrier Permeability
A novel series of 3-(2-substituted-3-oxo-2,3-dihydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridines (5-38) were synthesized and evaluated for their in vitro adenosine A1 and A(2A) receptor binding activities, and in vitro metabolism by rat liver in order to search for orallyactive compounds. Most of the test compounds were potent adenosine A1 receptorantagonists with high A1 selectivity and the