SYNTHESIS, BENZODIAZEPINE RECEPTOR AFFINITY AND IN-VIVO TESTING OF -ALKYLPYRAZOL-3'-YL)PYRAZOLO[1,5-A]PYRIMIDIN-7-ONE OR 5'-YL)PYRAZOLO[1,5-A]PYRIMIDIN-7-ONE

The synthesis of a series of 3-aryl-4,7-dihydro-6-(N-1'-alkylpyrazol-3 or 5'-yl)pyrazolo[1,5-a]pyrimidin-7-ones and their in vitro biologica l evaluation as ligands for benzodiazepine receptor (BzR) are describe d. The in vitro activities, as determined by an analysis of GABA (gamm a-aminobutyric acid) shift ratios, and binding affinities of these com pounds to BzR are compared in terms of the electronic, lipophilic and steric effect changes of their substituents either at the 3-position o r at the N-1' of 6-(pyrazol-3'(5')-yl) moiety. The most interesting co mpounds were tested in vivo.