abstract |
FIELD OF THE INVENTION The present invention relates to novel spiro (quinazolinylpiperidine) derivatives of formula (I) and optionally pharmaceutically acceptable acid addition salts thereof, wherein X is carbonyl, carbonyl, -CONH, -CSNH, or sulfonyl; R is a straight or branched C 1-4 alkyl group optionally substituted with 1 to 3 halogen atoms, or aryl optionally substituted with 1 to 5 halogen atoms, C 1-4 alkyl, C 1-4 alkoxy, or 1-2 nitro groups; or aralkyl; or X and R are together hydrogen. The novel compounds of the invention have mainly a memory-enhancing effect. |