1,2,4-TRIAZOLO[4,3-a]PYRIDINE DERIVATIVES AND THEIR USE AS POSITIVE ALLOSTERIC MODULATORS OF MGLUR2 RECEPTORS

A compound of formula (I)

• or a stereochemically isomeric form thereof,
• wherein
• R1 is selected from the group consisting of C1-6alkyl, (C3-8cycloalkyl)C1-3alkyl, (C1-3alkyloxy)C1-3alkyl, and C1-3alkyl substituted with 1, 2 or 3 fluoro substituents;
• R2 is selected from the group consisting of Cl, CF3, —CN and cyclopropyl;
• R3 is selected from the group consisting of hydrogen, methyl and CF3;
• R4 is selected from the group consisting of hydrogen and methyl;
• or R3 and R4 together with the carbon to which they are bound form a cyclopropyl ring or a carbonyl group;
• L is selected from the group consisting of (L-a), (L-b), (L-c), (L-d), (L-e), (L-f), (L-g) and (L-h):
• wherein
• R5a, R5b, R5c and R5d are each independently selected from the group consisting of phenyl;
• phenyl substituted with 1 or 2 substituents each independently selected from the group consisting of C1-3alkyloxy and halo;
• pyridinyl;
• pyridinyl substituted with 1 or 2 substituents each independently selected from the group consisting of C1-3alkyl, C1-3alkyloxy and halo;
• pyrimidinyl;
• and pyrimidinyl substituted with 1 or 2 substituents each independently selected from the group consisting of C1-3alkyl, C1-3alkyloxy and halo;
• R6e is selected from the group consisting of hydrogen and C1-3alkyl;
• R5f, R5g, and R5h are each independently selected from phenyl and phenyl substituted with 1 or 2 fluoro substituents;
• R6a, R6b and R6c are each independently selected from the group consisting of hydrogen;
• fluoro;
• C1-3alkyl;
• C1-3alkyl substituted with 1, 2 or 3 fluoro substituents;
• C1-3alkyloxy;
• C1-3alkyloxy substituted with 1, 2 or 3 fluoro substituents;
• and C3-6cycloalkyl;
• R6h is C1-3alkyl;
• R7a, R8a, R7b, R8b, R7c, R8c, R7d, and R8d are each independently selected from the group consisting of hydrogen, halo and methyl;
• or each R7a and R8a, R7b and R8b, R7c and R8c, and R7d and R8d together with the carbon to which they are attached form a cyclopropyl or a carbonyl group;
• R9b is selected from the group consisting of hydrogen, C1-3alkyl and C3-6cycloalkyl;
• wherein
• each halo is selected from the group consisting of fluoro, chloro, bromo and iodo;
• or a pharmaceutically acceptable salt or a solvate thereof.