Synthesis and use of FSCPX, an irreversible adenosine A1 antagonist, as a 'receptor knock-down' tool

A new preparative synthetic route for the irreversible adenosine A1 antagonist 8-cyclopentyl-3-N-[3-((3-(4-fluorosulphonyl)benzoyl)-oxy)-propyl]-1-N-propyl-xanthine (FSCPX, 1) is described. The availability of ample amounts of the irreversible antagonist FSCPX allowed us to use FSCPX as a research tool for adenosine A1 receptors in in vivo experiments. After verification of the irreversible antagonistic function of FSCPX in in vitro experiments, FSCPX was used successfully as a 'receptor knock-down' tool in in vivo experiments on conscious rats.