| abstract |
The present invention relates to a compound of formula I wherein R1' is CH3; R1 is methyl, ethyl, CF3, CH2OH, cyclopropyl or cyano; or R1' and R1 together form a 1,1-di-oxy group- Tetrahydro-thiophen-3-yl ring; R2 is hydrogen, methyl, ethyl, isopropyl, tert-butyl or cyclopropyl; R3 is Cl, F, CF3, cyano, methyl, methoxy Or cyclopropyl; R4 is hydrogen, methyl or F; X is N or CH; Y is N or CH; the restriction is that X and Y are not simultaneously CH; or a pharmaceutically acceptable salt or acid addition salt thereof , racemic mixtures 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 autism spectrum disorders. |