[Problems] Provided is a compound which has an antagonistic action on a muscarinic M
3
receptor and is useful as an active ingredient of a prophylactic and/or therapeutic agent for an inflammatory disease such as a chronic obstructive pulmonary disease (COPD), asthma and the like.
[Means for Solving Problems] The present inventors have made studies on a compound having an antagonistic action on the binding of a muscarinic M
3
receptor, and they have found that an aza-bridged-ring compound or a salt thereof has an antagonistic action on the binding of a muscarinic M
3
receptor, thereby completing the present invention. The aza-bridged-ring compound of the present invention has an antagonistic action on the binding of a muscarinic M
3
receptor, and can be used as a prophylactic and/or therapeutic agent for an inflammatory disease such as a chronic obstructive pulmonary disease (COPD), asthma and the like.
Compounds of formula I:
or salts thereof are disclosed. Also disclosed are pharmaceutical compositions comprising a compound of formula I, processes for preparing compounds of formula I, intermediates useful for preparing compounds of formula I and therapeutic methods for treating a Retroviridae viral infection including an infection caused by the HIV virus.