Synthesis and biological evaluation of pyrazoles and pyrazole-containing polycyclic derivatives as new ligands of central and peripheral benzodiazepine receptors
A series of new pyrazole-condensed 6,5,5 tricyclic compounds were synthesized and tested to evaluate their binding affinities at both
central (CBR) and peripheral (PBR) benzodiazepine receptors. Some 1-aryl-5-phenylpyrazole derivatives were also prepared and tested for
comparison with their corresponding rigid tricyclic analogs.Among the newly synthesized 1-aryl-1,4-dihydro-indeno[1,2-c]pyrazoles bearing
both an ethoxycarbonyl group at position 3 and a carbonyl function at the position 4, compound 4b emerged as a new potent (IC50 = 26.4 nM)
and selective CBR ligand. The 4-oxo-1-aryl-1,4-dihydro-indeno[1,2-c]pyrazole diethylamide derivative 14a was instead identified as a
relatively potent (IC50 = 124 nM) but highly selective PBR ligand