The present invention relates to compounds of formula I wherein Y is C-R1'; R1' is hydrogen, F or Cl; R1 is F or Cl; R2 is hydrogen or lower alkyl; R3 is phenyl, pyridinyl or isothiazolyl, wherein the N atom in the pyridinyl group may be in different positions, optionally substituted by one or two halgen atoms; R4 is hydrogen or lower alkyl; Het is a 5-membered heteroaryl group, containg two or three heteroatoms, selected from N, O or S, optionally substituted by lower alkyl, cycloalkyl, lower alkoxyalkyl, heterocycloalkyl, wherein the hetero-atom is O, or lower alkyl substituted by hydroxy, or is a bicyclic heteroaromatic ring, containing two or three N-heteroatoms selected from the groups, or; 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.
Ethynyl derivatives