Benzylidene ketal derivatives as M2 muscarinic receptor antagonists.

Benzylidene ketal derivatives were investigated as selective M2 receptor antagonists for the treatment of Alzheimer's disease. Compound 10 was discovered to have subnanomolar M2 receptor affinity and 100-fold selectivity against other muscarinic receptors. Also, 10 demonstrated in vivo efficacy in rodent models of muscarinic activity and cognition.

Diphenylsulfone muscarinic antagonists: piperidine derivatives with high M2 selectivity and improved potency.

Piperidine analogues of our previously described piperazine muscarinic antagonists are described. Piperidine analogues show a distinct structure-activity relationship (SAR) that differs from comparable piperazines. Compounds with high selectivity and improved potency for the M2 receptor have been identified.