| 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; A is a direct bond or (CHR3)m, m being 1-3; X is hydrogen, loweralkyl, cycloalkyl, loweralkoxy, halogen, hydroxy, nitro, trifluoromethyl, formyl, loweralkylcarbonyl, arylcarbonyl, -SH, loweralkylthio, -NHCOR4 or -NR5R6, R4 being hydrogen or loweralkyl, and R5 and R6 being independently hydrogen, loweralkyl or cycloalkyl; Y is CH2, O, S or NR7; and each R2, each R3 and R7 are independently hydrogen, loweralkyl or arylloweralkyl or taken two at a time form a methylene or ethylene bridge constituting a part of a five-membered or larger ring, with the proviso that when Y is CH2, R2 and R3 must together constitute a methylene or ethylene bridge; stereo, optical and geometrical isomers thereof, and pharmaceutically acceptable acid addition salts thereof, which are useful for enhancing memory. |