Synthesis and Evaluation of a Set of 4-Phenylpiperidines and 4-Phenylpiperazines as D<sub>2</sub> Receptor Ligands and the Discovery of the Dopaminergic Stabilizer 4-[3-(Methylsulfonyl)phenyl]-1-propylpiperidine (Huntexil, Pridopidine, ACR16)
Modification of the partial dopamine type 2 receptor (D2) agonist 3-(1-benzylpiperidin-4-yl)phenol (9a) generated a series of novel functional D2 antagonists with fast-off kinetic properties. A representative of this series, pridopidine (4-[3-(methylsulfonyl)phenyl]-1-propylpiperidine; ACR16, 12b), bound competitively with low affinity to D2 in vitro, without displaying properties essential for interaction