| 摘要 |
There are disclosed compounds having the formula <CHEM> where n is 1, 2 or 3; X is hydrogen, loweralkyl, loweralkoxy, halogen, hydroxy, nitro or trifluoromethyl; R1 and R2 are each independently hydrogen, loweralkyl or arylloweralkyl, but both may not be arylloweralkyl simultaneously; R3 and R4 are each independently hydrogen, loweralkyl, arylloweralkyl, formyl or loweralkylcarbonyl, or alternatively the group -NR3R4 taken as a whole constitutes <CHEM> stereo isomers thereof and pharmaceutically acceptable acid addition salts thereof and a process for their preparation. The compounds are useful for the treatment of various memory dysfunctions characterized by decreased cholingeric function, such as Alzheimer's disease, and can, therefore, be used as medicaments. |
