The present invention relates to compounds of formula I, wherein Y is N or C-R1'; R1' is hydrogen or F; R1 is hydrogen, halogen or lower alkyl substituted by halogen; R2 is hydrogen or lower alkyl; or R2 forms together with R4 a 6 membered heterocyclic ring containing -CH2-CH2-O-CH2- or -CH2-CH2-NR-C(O)-; R is hydrogen, lower alkyl, phenyl or benzyl; R3 is phenyl or pyridinyl, wherein the N atom in the pyridinyl group may be in different positions; R4' is hydrogen, lower alkyl or lower alkoxyalkyl; R4 is hydrogen, lower alkyl, phenyl optionally substituted by halogen or lower alkoxy, or is cycloalkyl, or is pyridinyl optionally substituted by halogen, lower alkyl, lower alkoxy or =0, or is pyrimidinyl optionally substituted by lower alkyl, lower alkoxy or =0, or is 1 -lower alkyl-pyridinyl, or is pyrazinyl, or is pyridazinyl optionally substituted by lower alkyl, lower alkoxy or =0, or is l-methylpyrrolo[2,3-b]pyridine-5-yl, or is 6-imidazo[l,2- b]pyridazin-6-yl; or R4 forms together with R4' a 4, 5 or 6 membered heterocyclic ring containing -(CH2)5-, -CH2-CH2-O-CH2-CH2-, -CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-, -CH2-O-CH2-CH2- or CH2-CH2-CH2-O-CH2; R5 and R5' are hydrogen or lower alkyl; or R4 forms together with R5 a saturated 5- membered ring containing -CH2-CH2-CH2-; 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. The compounds may be used for the treatment of Parkinson's disease, anxiety, emesis, obsessive compulsive disorder, autism, neuroprotection, cancer, depression and diabetes type 2.