NOVEL TRICYCLIC 3,4-DIHYDRO-2H-PYRIDO[1,2-a]PYRAZINE-1,6-DIONE DERIVATIVES AS GAMMA SECRETASE MODULATORS

A compound of Formula (I)

• a tautomer or a stereoisomeric form thereof, wherein
• R1 is phenyl, napthyl, indolyl, benzothienyl, benzothiazolyl or benzofuranyl;
• each optionally substituted with one, two or three substituents each independently selected from the group consisting of halo and C1-4alkyl optionally substituted with one, two or three halo substituents;
• L is attached at position a or b;
• L is selected from the group consisting of a covalent bond, —C1-6alkanediyl- and —O—C1-6alkanediyl-;
• Y is -Q-(CH2)m—, —CH2-Q-CH2—, —(CH2)n—,
• —(CH2)n— wherein one —CH2— is substituted with hydroxyl and C1-4alkyl, or
• —(CH2)n— wherein one —CH2— is substituted with one hydroxyl;
• n represents 1, 2 or 3;
• m represents 1 or 2;
• Q is O or NR6;
• R6 is hydrogen or C1-4alkyl;
• Z is methylene or 1,2-ethanediyl, wherein methylene or 1,2-ethanediyl is optionally substituted with one or two C1-4alkyl substituents;
• R2 is hydrogen, halo or C1-4alkyl;
• R3 is hydrogen or C1-4alkyl;
• R4 is hydrogen, halo or C1-4alkyl;
• X is CR5 or N;
• R5 is hydrogen or C1-4alkyl;
• or a pharmaceutically acceptable addition salt thereof.