N-Hydroxyalkyl Derivatives of 3β-Phenyltropane and 1-Methylspiro[1H-indoline-3,4‘-piperidine]:  Vesamicol Analogues with Affinity for Monoamine Transporters

As part of our ongoing structure−activity studies of the vesicular acetylcholine transporter ligand 2-(4-phenylpiperidino)cyclohexanol (vesamicol, 1), 22 N-hydroxy(phenyl)alkyl derivatives of 3β-phenyltropane, 6, and 1-methylspiro[1H-indoline-3,4‘-piperidine], 7, were synthesized and tested for binding in vitro. Although a few compounds displayed moderately high affinity for the vesicular acetylcholine transporter, no compound was more potent than the prototypical vesicular acetylcholine transporter ligand vesamicol. However, a few derivatives of 6 displayed higher affinity for the dopamine transporter than cocaine. We conclude that modification of the piperidyl fragment of 1 will not lead to more potent vesicular acetylcholine transporter ligands.