摘要 |
Disclosed are the compounds of formula I <CHEM> wherein R1-R3 represent hydrogen or lower alkyl; m represents the integer 2 or 3; n represents the integer 1 or 2; Het represents a pyrrole or imidazole ring bonded at any two adjacent positions and optionally substituted by one or two of lower alkyl; and pharmaceutically acceptable salts of compounds of formula I wherein Het represents optionally substituted imidazole; their methods of preparation; pharmaceutical compositions thereof, and their use for treating cognitive disorders in mammals. They can be prepared for example by condensing a compound of the formula Het min -(CH2)m-NH2 with a compound of the formula <CHEM> R |