Imidazo[1,2-A]pyridine derivatives and their use as positive allosteric modulators of mGluR2 receptors

A compound having the formula (I)

• or a stereochemically isomeric form thereof, wherein
• R1 is C1-6 alkyl;
• C3-6 cycloalkyl;
• trifluoromethyl;
• C1-3 alkyl substituted with trifluoromethyl, C3-7 cycloalkyl, phenyl, or phenyl substituted with C1-3 alkyl, C1-3alkyloxy, cyano, halo, trifluoromethyl;
• phenyl;
• phenyl substituted with 1 or 2 substituents selected from the group consisting of C1-3 alkyl, cyano, halo, trifluoromethyl;
• or 4-tetrahydropyranyl;
• R2 is cyano, halo, trifluoromethyl, C1-3 alkyl or cyclopropyl;
• R3 is a radical of formula (a) or (b) or (d)
• R4 is hydroxyC3-6 cycloalkyl;
• pyridinyl;
• pyridinyl substituted with one or two C1-3 alkyl groups;
• pyrimidinyl;
• pyrimidinyl substituted with one or two C1-3 alkyl groups;
• phenyl;
• phenyl substituted with 1 or 2 substituents selected from the group consisting of halo, C1-3 alkyl, hydroxyC1-3 alkyl, mono- or polyhaloC1-3 alkyl, cyano, hydroxyl, carboxyl, C1-3 alkyloxyC1-3 alkyl, C1-3 alkyloxy, mono- or polyhalo-C1-3 alkyloxy, and morpholinyl;
• R5 is hydrogen, fluoro, hydroxyl, hydroxyC1-3 alkyl, fluoroC1-3 alkyl, morpholinyl or cyano;
• X is C or N in which case R5 represent the electron pair on N;
• or
• R4—X—R5 represents a radical of formula (h) or (i) or (j)
• n is 0 or 1;
• q is 1 or 2;
• R6 is C1-3 alkyl;
• C3-6cycloalkyl;
• hydroxyC2-4alkyl;
• (C3-6cycloalkyl)C1-3alkyl;
• phenyl;
• pyridinyl;
• or phenyl or pyridinyl substituted with one or two substituents selected from the group consisting of halo, C1-3alkyl, C1-3alkoxy, hydroxyC1-3alkyl, trifluoromethyl and (CH2)m—CO2H, wherein m=0, 1, or 2;
• or
• R6 is a cyclic radical of formula (k)
• wherein R8 is hydrogen, C1-3alkyl, hydroxyC1-3alkyl;
• p is 1 or 2;
• Z is O, CH2 or CR9(OH) wherein R9 is hydrogen or C1-3alkyl;
• R7 is hydrogen, halo or trifluoromethyl;
• Y is a covalent bond, O, NH, S, C(OH)(CH3), —CH2—O—, —O—CH2—, CHF or CF2;
• or
• R6—Y is morpholinyl, pyrrolidinyl, or piperidinyl optionally substituted with hydroxyl or hydroxyC1-3alkyl;
• and
• A is O or NH;
• or a pharmaceutically acceptable salt thereof.