| abstract |
The present invention relates to a compound of formula I: □I wherein R1' is CH3; R1 is CH3, ethyl, CF3, CH2OH, cyclopropyl or cyano, or R1' and R1 together form a 1,1-dioxy group -tetrahydro-thiophen-3-yl ring; R2 is hydrogen, CH3, ethyl, isopropyl, tert-butyl, cyclopropyl, cyclopropyl-methyl or hydroxy-methyl; R3 is hydrogen, Cl , F, CF3, CH3, isopropyl, methoxy, cyano or cyclopropyl; R4 is hydrogen, CH3, F or Cl; or a pharmaceutically acceptable salt or acid addition salt thereof, a racemic mixture Or their corresponding enantiomers and/or optical isomers and/or stereoisomers. The compounds of formula I are useful in the treatment of psychiatric disorders such as schizophrenia, bipolar disorder, obsessive-compulsive disorder or autistic disorder. |