Discovery of novel quaternary ammonium derivatives of (3R)-quinuclidinyl carbamates as potent and long acting muscarinic antagonists.

Abstract Novel quaternary ammonium derivatives of N , N -disubstituted (3 R )-quinuclidinyl carbamates have been identified as potent M 3 muscarinic antagonists with long duration of action in an in vivo model of bronchoconstriction. These compounds have also presented a high level of metabolic transformation (human liver microsomes). The synthesis, structure–activity relationships and biological evaluation of these compounds are reported.