The present invention relates to ethynyl derivatives of formula Iwherein R1is hydrogen or halogen； R2is C1-3-alkyl or -(CH2)n-O-CH3； n is 2 or 3； m is 1 or 2； or to a pharmaceutically acceptable acid addition salt, to a racemic mixture, or to its corresponding enantiomer and/or optical isomer and/or stereoisomer thereof.It has been found that the compounds of general formula I are allosteric modulators of the metabotropic glutamate receptor subtype 5 (mGluR5) with improved properties for the treatment of schizophrenia, cognitive diseases, fragile X syndrome or autism.本發明係關於一種式I之乙炔基衍生物：其中R1係氫或鹵素；R2係C1-3-烷基或-(CH2)n-O-CH3；n係2或3；m係1或2；或其藥學上可接受之酸加成鹽、外消旋混合物或其對應的對映異構物及/或光學異構物及/或立體異構物。已發現通式I化合物係用於治療精神分裂症、認知疾病、X染色體脆折症或自閉症的具有改良性質的代謝型麩胺酸鹽受體亞型5(mGluR5)之異位調節劑。
