| abstract |
Compounds of general formula I ##STR1## wherein: X represents oxygen or sulphur; n each of R 1 and R 3 independently represents hydrogen or a C 1 -C 4 alkyl group; n Ar represents: n a phenyl ring optionally substituted by one, two or three C 1 -C 4 alkoxy groups and/or by one or two halogen atoms; a phenyl ring of the general formula ##STR2## wherein R 2 represents halogen, 4,5-benzo, C 1 -C 8 alkoxy, C 1 -C 4 alkylcarbonyl or Am, wherein Am represents amino, methylamino or dimethylamino, n R 4 represents C 1 -C 8 alkyl, n n is 1 or 2; or n a pyrimidinyl moiety of the general formula ##STR3## wherein R 5 is C 1 -C 4 alkyl; and their N-oxides and pharmaceutically acceptable salts are useful as memory- and/or learning-enhancing agents. A preferred compound is R-(+)-4-amino-N-(1-azabicyclo[2.2.2]oct-3-yl)-5-chloro-2-methoxybenzamide. |