| abstract |
The present invention relates to ethinyl derivatives of formula I, wherein X is N or CR, where R is hydrogen or halogen, G is N or CH, provided that at most one of G or X can be nitrogen. , R1 is a phenyl group or a pyridinyl group, which are optionally substituted with halogen, R2 is hydrogen, a lower alkyl group, a hydroxy group, a lower alkoxy group or a C (O) O-benzyl group, R3, R3 ', R4 , R4 ', R6, R6' are each hydrogen or a lower alkyl group or R6 and R4 may form together with the carbon atom in attached to a C 4-6 -cycloalkyl ring, if m is 0 and n is 1 or 2, R 5 is hydrogen or a lower alkyl group, n is 0, 1 or 2, m is 0 or 1, with provided that n and m are not concomitantly 0 or with a pharmaceutically acceptable acid addition salt, with a racemic mixture, or with the corresponding enantiomer and / or optical isomer and / or stereoisomer thereof. Surprisingly, compounds of the general formula I are positive allosteric modulators (PAM) of the metabotropic glutamate receptor of subtype 5 (mGluR5). They can be used to treat schizophrenia or cognitive disorders. |