| abstract |
The present invention relates to a new process for the preparation of compounds of the general formulae <CHEM> wherein R<1>- R<4> are, independently from each other, hydrogen, halogen, hydroxy, amino, nitro, lower-alkyl-sulfonylamido, or acetamido; R<5>-R<8> are, independently from each other hydrogen, lower-alkyl, halogen, trifluoromethyl or lower-alkoxy; and their pharmaceutically acceptable acid addition salts. The compounds of formulae I-a and I-b are NMDA (N-methyl-D-aspartate)-receptor-subtype selective blockers, which have a key function in modulating neuronal activity and plasticity which makes them key players in mediating processes underlying development of CNS including learning and memory formation and function. |