A Novel Selective GABA<sub>A</sub> α1 Receptor Agonist Displaying Sedative and Anxiolytic-like Properties in Rodents

In our pursuit to identify selective ligands for Bz/GABA<sub>A</sub> receptor subtypes, a novel pyrazolo[1,5-<i>a</i>]pyrimidine derivative (<b>4</b>), the azaisostere of zolpidem, was synthesized and evaluated in vitro on bovine brain homogenate and on recombinant benzodiazepine receptors (αxβ2/3γ2, <i>x </i>= 1−3, 5) expressed in HEK293 cells. Compound <b>4</b> displayed affinity only for α1β2γ2 subtype (<i>K</i><sub>i</sub> = 31 nM), and in an in-depth, in vivo study it revealed sedative and anxiolytic-like properties without any amnesic and myorelaxant effects in rodents.