Compounds of Formula I:
wherein X, Y, Z, R
1
, R
2
, R
3
, R
4
are as defined herein, and pharmaceutically acceptable salts thereof, are described as useful for the treatment of cognitive deficits associated with schizophrenia and other psychiatric, neurodegenerative and/or neurological disorders in mammals, including humans.
Compounds of Formula I:
wherein X, Y, Z, R1, R2, R3, R4 are as defined herein, and pharmaceutically acceptable salts thereof, are described as useful for the treatment of cognitive deficits associated with schizophrenia and other psychiatric, neurodegenerative and/or neurological disorders in mammals, including humans.