| abstract |
The present invention is concerned with substituted imidazo [1,5-a] [1,2,4] triazolo [1,5d] [1,4]benzodiazepine derivatives of formula (I) wherein R1 is hydrogen, halogen, lower alkyl, lower alkynyl, cycloalkyl, heterocycloalkyl, benzyl, cyano, lower alkoxy, OCF3, -NHR, -NHC(O)R or -NHSO2R; R2 is lower alkyl substituted by halogen; R3 is hydrogen, methyl or aryl; R is lower alkyl, cycloalkyl or aryl; and with their pharmaceutically acceptable acid addition salts. It has been found that this class of compounds show high affinity and selectivity for GABA A α5 receptor binding sites and might be useful as cognitive enhancer or for the treatment of cognitive disorders, anxiety, schizophrenia or Alzheimer's disease. |