Gamma secretase inhibitors

A compound of Formula (I)

• or a pharmaceutically acceptable salt thereof, wherein
• R is a 5-6 membered heteroaryl containing 1-2 nitrogen atoms optionally substituted with one L1 group;
• or a —(C1-C6)alkyl(5-6 membered)heteroaryl containing 1-3 heteroatoms selected from N and O optionally substituted with one L1 group, with the proviso that the (5-6 membered)heteroaryl of the —(C1-C2)alkyl(5-6 membered)heteroaryl is not furanyl;
• R1 is independently selected from the group consisting halogen, (C1-C6)alkyl, —CN, —CF3, —O—(C1-C6)alkyl, —O-(halo(C1-C6)alkyl), —C(O)—O—(C1-C6)-OH-substituted (C1-C4)alkyl, halo(C1-C6)alkyl, —(C1-C4)alkoxy-OH, —(C1-C4)alkoxy(C1-C4)alkoxy and —S(O)2(C1-C6)alkyl;
• n is 0, 1, 2, or 3;
• Ar is selected from the group consisting of phenyl optionally substituted with 1 or 2 L2 groups, and pyridyl optionally substituted with 1 or 2 L2 groups;
• L1 is independently selected from the group consisting of —OCH3, —NH2, ═O, and (C1-C5)alkyl;
• and
• L2 is independently selected from the group consisting of halogen, (C1-C6)alkyl, —CN, —CF3, —O—(C1-C6)alkyl, —O-(halo(C1-C6)alkyl), —C(O)—O—(C1-C6)alkyl, —OH— substituted (C1-C6)alkyl, halo(C1-C6)alkyl, —OH-substituted (C1-C4)alkoxy, —(C1-C4)alkoxy(C1-C4)alkoxy and —S(O)2(C1-C6)alkyl.