The present invention relates to imidazole derivatives of the general formula (I) wherein R1 signifies halogen, lower alkyl or lower alkoxy； R2 signifies lower alkyl, lower hydro xyalkyl or lower alkoxyalkyl； R3 signifies hydrogen, lower alkyl, lower hydroxyalkyl or alkoxyalkyl； Q signifies either -N= or -CH=； R4 is a group of formula IIa or lIb (formula IIa and IIb) wherein X, Y and Z independently are -CH= or -N=, and whereby only one of X or Y can be a nitrogen atom； R5 and R6 independently are hydrogen, lower alkyl, lower hydroxyalkyl, lower alkoxyalkyl, -(CH2)m-(CO)O-lower alkyl, -(CH2)m-S(O)2-lower alkyl, -(CH2)m-C(O)-NR'R" and where m = 0-3 and R' and R'' are independently hydrogen or lower alkyl； as well as to pharmaceutically acceptable salts thereof. It has now surprisingly been found that the compounds of general formula (I) are metabotropic glutamate receptor antagonists. They can be used in the treatment or prevention of mGluR5 receptor mediated disorders.
