New mGluRl and mGluR5 receptor subtype preferring ligands of formula: (I) and/or salts and/or hydrates and/or solvates thereof, to the processes and intermediates for their preparation, to pharmaceutical compositions containing these compounds and to their use in therapy and/or prevention of a condition which requires modulation of mGluRl and mGluR5 receptors.FORMULE (I) wherein Ar1 represents an optionally substituted phenyl or heteroaryl group； Ar2 represents a substituted phenyl or an optionally substituted heteroaryl group； R1, R2, R3 and R4 represent independently a substituent selected from hydrogen, halogen, cyano, alkyl, alkoxy, hydroxy, trifluoromethyl, amino, alkylamino, dialkylamino, aminomethyl, alkylaminomethyl, dialkylaminomethyl
