Substituted 3,4-dihydro-2H-pyrido[1,2-a]pyrazine-1,6-diones as gamma secretase modulators

A compound of Formula (I):

• or a pharmaceutically acceptable addition salt, stereoisomer or tautomer thereof,
• wherein:
• X is CR6 or N;
• L is a covalent bond, —C(═O)—C1-6alkanediyl-, —C1-6alkanediyl-, or C1-6alkanediyl, wherein two germinal hydrogen atoms are replaced by C2-6alkanediyl;
• R0 is a ring system selected from the group consisting of piperidinyl optionally substituted with one or more substituents each independently selected from the group consisting of halo and C1-4alkyl optionally substituted with one or more halo substituents;
• R1 is Ar1 or Ar2;
• R2 is hydrogen or C1-4alkyl;
• R3 is hydrogen;
• R4 is hydrogen, halo or C1-4alkyl;
• R5 is hydrogen or C1-4alkyl;
• R6 is hydrogen or C1-4alkyl;
• R9 is hydrogen, C3-7cycloalkyl or phenyl;
• Ar1 is a ring system selected from the group consisting of thienyl, thiazolyl, pyrrolidinyl, piperidinyl, pyrazolyl, 4,5,6,7-tetrahydrobenzo[b]thienyl, 1,2-benzisoxazolyl, benzofuranyl, 2,3-dihydrobenzofuranyl, 1,3-dihydroisobenzofuranyl, 5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyridinyl, 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridinyl, 1,2,4-triazolo[4,3-a]pyridinyl, pyrazolo[1,5-a]pyridinyl, 3,4-dihydro-1-benzopyranyl, 1,2-benzisothiazolyl, indazolyl, and 1,2,3,4-tetrahydroisoquinolinyl, wherein said ring system is optionally substituted with one or more substituents each independently selected from the group consisting of halo, oxo, Ar3, R0, and C1-4alkyl optionally substituted with one or more substituents each independently selected from the group consisting of halo and C1-4alkyloxy;
• Ar2 is phenyl substituted with one substituent selected from the group consisting of OR9 and 3-azabicyclo[3.1.0]hexanyl, and further optionally substituted with one, two or three C1-4alkyloxy optionally substituted with one or more halo substituents;
• Ar3 is phenyl optionally substituted with one or more CF3 substituents;
• and
• Z is methylene.