The present invention relates to compounds of formula I wherein Y is N or C-R1’； G is a 5 or 6-membered aromatic or heteroaromatic ring containing 0, 1, 2 or 3 heteroatoms, selected from the group consisting of phenyl, pyridinyl with different N-positions, imidazolyl, pyrazinyl, pyrimidinyl, thiophenyl, thiazolyl, pyrazolyl or thiadiazolyl, which are optionally substituted by l, 2 or 3 substituents, selected from the group consisting of halogen, lower alkyl, lower alkoxy, lower alkoxy substituted by halogen or NRR’； R and R’ are independently from each other hydrogen or lower alkyl, or may form together with the N atom to which they are attached a five or six membered saturated heterocyclic group which may contain an additional oxygen, NH, or N-lower alkyl group； R1 is hydrogen, halogen or lower alkyl substituted by halogen； R1’ is hydrogen, halogen or lower alkyl substituted by halogen； R2 is hydrogen, lower alkyl, lower alkoxyalkyl, cycloalkyl or heterocycloalkyl； or R2 may form together with the closest carbon atom in group G a group for A being -CH2-, -CH2CH2, or -C(CH3)2-, R3 is phenyl or pyridinyl, wherein the N atom in the pyridinyl group may be in different positions； or to a pharmaceutically acceptable salt or acid addition salt, to a racemic mixture, or to its corresponding enantiomer and/or optical isomer and/or stereoisomer thereof. It has been surprisingly been found that the compounds of general formula I are positive allosteric modulators (PAMs) of metabotropic glutamate receptor 4 (mGluR4), useful for the treatment of Parkinson’s disease, anxiety, emesis, obsessive compulsive disorder, autism, neuroprotection, cancer, depression and diabetes type 2.本發明係關於式I之化合物其中Y 為N或C-R1'；G 為含有0、1、2或3個雜原子之5員或6員芳族或雜芳族環，其係選自由苯基、具有不同N-位置之吡啶基、咪唑基、吡嗪基、嘧啶基、苯硫基、噻唑基、吡唑基或噻二唑基組成之群，該等基團視情況經1、2或3個選自由鹵素、低碳烷基、低碳烷氧基、經鹵素取代之低碳烷氧基或NRR'組成之群的取代基取代；R及R'彼此獨立地為氫或低碳烷基，或可連同其所連接之N原子形成可含有額外的氧、NH或N-低碳烷基之五員或六員飽和雜環基；R1 為氫、鹵素或經鹵素取代之低碳烷基；R1' 為氫、鹵素或經鹵素取代之低碳烷基；R2 為氫、低碳烷基、低碳烷氧烷基、環烷基
