| abstract |
There are disclosed compounds having the formula <CHEM> wherein n is 1-4; R1 is hydrogen, alkyl, aryl, arylloweralkyl, naphthyl, furyl, thienyl, pyridinyl or pyrrolyl; X is hydrogen, loweralkyl, cycloalkyl, loweralkoxy, halogen, hydroxy, nitro, trifluoromethyl, formyl, loweralkylcarbonyl, arylcarbonyl, -SH, loweralkylthio, -NHCOR2 or -NR3R4 where R2 is hydrogen or loweralkyl, and R3 and R4 are independently hydrogen, loweralkyl or cycloalkyl; stereo, optical and geometrical isomers thereof, and pharmaceutically acceptable acid addition salts thereof, which are useful for enhancing memory and pharmaceutical compositions comprising an effective memory enhancing amount of such a compound. |