摘要 |
This invention relates to compounds of the formula (see formula I) wherein R1 is hydrogen, (C1-C12)alkylcarbonyl, (C1-C12)alkoxycarbonyl, mono(C1-C12)alkylaminocarbonyl or di(C1-C8)alkylaminocarbonyl; R2 is hydrogen, (C3-C12)alkenylcarbonyloxy, (C3-C12)cycloalkylcarbonyloxy, (C3-C12)cycloalkylaminocarbonyloxy, (C3-C12)alkynylcarbonyloxy, (C3-12)cycloalkyl(C1-C12)-alkylcarbonyloxy, oxygen containing heterocyclyloxy, oxygen containing heterocyclylcarbonyloxy, sulfur containing heterocyclyloxy, sulfur containing heterocyclylcarbonyloxy, nitrogen containing heterocyclyloxy, nitrogen containing heterocyclylcarbonyloxy, haloalkylsulfonyloxy, (C1-C6)alkylsilyloxy; R3 is hydrogen, halo or (C1-C4)alkyl; R4 is hydrogen or (C1-C6)alkyl; with the proviso that R1 and R2 are not both hydrogen when R3 and R4 are hydrogen; all geometric, and optical and stereoisomers thereof, or a pharmaceutically acceptable addition salt thereof; which compounds are useful for the treatment of memory disfunction characterized by decreased cholinergic function, such as Alzheimer's disease. Pharmaceutical compositions containing the compounds and methods for making and using the compounds are also encompassed within the present invention.
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