| abstract |
Selective muscarinic receptor antagonists of formula (I): <IMAGE> (I) wherein R1 and R2 are both optionally substituted phenyl, the broken line is an optional bond, X is >COH-, >SiOH- or CH- when the double bond is absent or is >C= when the double bond is present, X being attached to a carbon atom of A, A is selected from certain piperidine and pyrrolidine groups, n is 1 to 3 and R3 is optionally substituted phenyl or thienyl, pyridyl or pyrazinyl. |