Cyclohexyl sulphones as gamma-secretase inhibitors

A compound of formula I:

• wherein n is 1 or 2;
• R1 represents CF3 or C1-6alkyl, C2-6alkenyl, C3-9cycloalkyl or C3-6cycloalkylC1-6alkyl, any of which may bear up to 2 substituents selected from halogen, CN, CF3, OR3, COR3, CO2R3, OCOR4, SO2R4, N(R5)2, and CON(R5)2,
• or R1 represents aryl, arylC1-6alkyl, C-heterocyclyl or C-heterocyclylC1-6alkyl;
• R2 represents H or C1-4alkyl;
• R3 represents H, C1-4alkyl, phenyl or heteroaryl;
• R4 represents C1-4alkyl, phenyl or heteroaryl;
• R5 represents H or C1-4alkyl, or two R5 groups together with a nitrogen atom to which they are mutually attached complete an azetidine, pyrrolidine, piperidine, morpholine, thiomorpholine or thiomorpholine-1,1-dioxide ring;
• Ar1 and Ar2 independently represent phenyl or heteroaryl, either of which bears 0-3 substituents independently selected from halogen, CN, NO2, CF3, CHF2, OH, OCF3, CHO, CH═NOH, C1-4alkoxy, C1-4alkoxycarbonyl, C2-6acyl, C2-6alkenyl and C1-4alkyl which optionally bears a substituent selected from halogen, CN, NO2, CF3, OH and C1-4alkoxy;
• aryl at every occurrence thereof refers to phenyl or heteroaryl which optionally bear up to 3 substituents selected from halogen, CN, NO2, CF3, OCF3, OR3, COR3, CO2R3, OCOR4, N(R5)2, CON(R5)2 and optionally-substituted C1-6alkyl, C1-6alkoxy, C2-6alkenyl or C2-6alkenyloxy wherein the substituent is selected from halogen, CN, CF3, phenyl, OR3, CO2R3, OCOR4, N(R5)2 and CON(R5)2;
• and
• C-heterocyclyl and N-heterocyclyl at every occurrence thereof refer respectively to a heterocyclic ring system bonded through carbon or nitrogen, said ring system being non-aromatic and comprising up to 10 atoms, at least one of which is O, N or S, and optionally bearing up to 3 substituents selected from oxo, halogen, CN, NO2, CF3, OCF3, OR3, COR3, CO2R3, OCOR4, OSO2R4, N(R5)2, CON(R5)2 and optionally-substituted phenyl, C1-6alkyl, C1-6alkoxy, C2-6alkenyl or C2-6alkenyloxy wherein the substituent is selected from halogen, CN, CF3, OR3, CO2R3, OCOR4, N(R5)2 and CON(R5)2;
• or a pharmaceutically acceptable salt thereof.