Design and synthesis of piperidinyl piperidine analogues as potent and selective M2 muscarinic receptor antagonists

Identification of a number of highly potent M-2 receptor antagonists with >100-fold selectivity against the M-1 and M-3 receptor subtypes is described. In the rat microdialysis assay, this series of compounds showed pronounced enhancement of brain acetylcholine release after oral administration. (C) 2000 Elsevier Science Ltd. All rights reserved.