| abstract |
The present invention provides compounds of formula (I) or pharmaceutically acceptable salts thereof, wherein R 1-3 , R 5-7 , a, X, Y, Y', Y" and Z are as defined in the specification. These compounds are Muscarinic receptor antagonists. The invention also provides pharmaceutical compositions containing the compounds, processes for preparing the compounds, and methods of using the compounds, for example, in the treatment of pulmonary diseases such as chronic obstructive pulmonary disease and asthma. |