The present invention provides, in part, compounds of Formula I: N-oxides thereof, and pharmaceutically acceptable salts of the compounds or N-oxides; processes for the preparation of; intermediates used in the preparation of; and compositions containing such compounds, N-oxides, or salts, and their uses for treating M1-mediated (or M1-associated) disorders including, e.g., Alzheimer's disease, schizophrenia (e.g., its cognitive and negative symptoms), pain, addiction, and a sleep disorder.