Pyrimidinone compounds for use in the treatment of diseases or conditions mediated by LP-PLA2

A compound of Formula (I) or a pharmaceutically acceptable salt thereof

• wherein:
• n is 1, 2 or 3;
• X is CH2, O, S, NH, or N(C1-C6alkyl);
• Y is H, C1-C6alkyl or C3-C6 cycloalkyl;
• Z is H, C1-C6alkyl, C1-C6-haloalkyl, —CH2-phenyl, —CH2-heteroaryl, —(CH2)2C(═O)—OCH3, —CH2-heterocycloalkyl, —CH2COOH, —CH2C(═O)-heterocycloalkyl, wherein phenyl, heteroaryl or heterocycloalkyl may be optionally substituted with one or more substituents independently selected from the group consisting of C1-C6alkyl, C1-C6alkoxyl, C1-C3haloalkyl, CN, halo and —OH;
• Ra is hydrogen or C1-C3alkyl;
• Ar is phenyl or heteroaryl which is a monocyclic ring system having 6 members atoms, either of which is optionally substituted with one or more substituents independently selected from the group consisting of CN, halo, C1-C6alkyl, C1-C6alkoxy, and C1-C6haloalkyl;
• and
• Ar′ is phenyl or heteroaryl, either of which is optionally substituted with one or more substituents independently selected from the group consisting of CN, halo, C1-C6alkyl, C1-C6alkoxy, C1-C6haloalkyl, and —O—C1-C6haloalkyl;
• and
• with the proviso that when X is S and Z is C1-C6alkyl, Ar′ is not unsubstituted phenyl.