The invention relates to compounds of formula (I) wherein R1 is (A), or is phenyl, pyridinyl or pyridazinyl, wherein phenyl, pyridinyl and pyridazinyl may optionally be substituted by cyano, lower alkyl, halogen-substituted phenyl, lower alkyl-substituted [1,2,4]oxadiazol-3-yl or by 2-oxo-piperidin-1-yl X is NR or O R is C(O)-lower alkyl, -C(O)-cycloalkyl substituted by lower alkyl, cycloalkyl or is phenyl, pyridinyl or pyridazinyl, wherein phenyl, pyridinyl and pyridazinyl may optionally be substituted by lower alkyl, lower alkoxy, cyano, -C(O)-lower alkyl, halogen or lower alkyl substituted by halogen R2 is hydrogen or lower alkyl R3 is hydrogen, halogen, cyano, lower alkyl or lower alkyl substituted by halogen R4 is hydrogen or lower alkyl wherein R2 and R4 are not simultaneously hydrogen or lower alkyl R5 is lower alkyl R6 halogen, hydroxy, lower alkyl, lower alkoxy, lower alkyl substituted by halogen, S(O)2-lower alkyl or cyano or to a pharmaceutically suitable acid addition salt thereof. It has been found that the present compounds are high potential NK-3 receptor antagonists for the treatment of depression, pain, psychosis, Parkinsons disease, schizophrenia, anxiety and attention deficit hyperactivity disorder (ADHD).Linvention concerne des composés de formule (I), dans laquelle R1 est (A) ou est phényle, pyridinyle ou pyridazinyle, phényle, pyridinyle et pyridazinyle pouvant éventuellement être substitués par cyano, alkyle inférieur, phényle à substitution halogène, [1,2,4]oxadiazol-3-yle à substitution alkyle inférieur ou par 2-oxo-pipéridin-1-yle X est NR ou O R est C(O)-alkyle inférieur, -C(O)-cycloalkyle substitué par alkyle inférieur, cycloalkyle ou est phényle, pyridinyle ou pyridazinyle, phényle, pyridinyle et pyridazinyle pouvant éventuellement être substitués par alkyle inférieur, alcoxy inférieur, cyano, -C(O)-alkyle inférieur, halogène ou alkyle inférieur substitué par halogène R2 est hydrogène ou alkyle inférieur R3 est hydrogène, halogène, c