| abstract |
The present invention relates to 4-hydroxy-piperidine derivatives of the general formulawhereinX denotes -O-, -NH-, -CH2-, -CH=, -CHOH-, -CO-, -S-, -SO- or -SO2-;R1-R4 are, independently from each other, hydrogen, hydroxy, lower-alkyl-sulfonylamino, 1- or 2-imidazolyl or acetamido;R5-R8 are, independently from each other, hydrogen, hydroxy, lower-alkyl, halogen, lower-alkoxy, trifluoromethyl or trifluoromethyloxy;a and b may be a double bond, provided that when "a" is a double bond, "b" cannot be a double bond;n is 0-2;m is 1-3;p is 0 or 1and to pharmaceutically acceptable addition salts thereof.Compounds of the present invention are NMDA(N-methyl-D-aspartate)-receptor subtype selective blockers, which can be used in mediating processes underlying development of CNS including learning and memory formation and function. |