Pyridine derivatives

A compound of the formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 is selected from the group consisting of:
• (i) phenyl, optionally substituted by one or more substituents each independently selected from the group consisting of halo, cyano, (C1-C4)alkyl, (C1-C4)alkoxy, halo(C1-C4)alkyl, halo(C1-C4)alkoxy, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkylamino and di-((C1-C4)alkyl)amino;
• and
• (ii) a 5-membered heteroaryl group comprising either (a) from 1 to 4 nitrogen atoms or (b) one oxygen or one sulphur atom and 1 or 2 nitrogen atoms, and wherein the heteroaryl group is optionally substituted by one substituent selected from the group consisting of (C1-C4)alkyl, (C1-C4)alkoxy, halo(C1-C4)alkyl, halo(C1-C4)alkoxy, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkylamino and di-((C1-C4)alkyl)amino;
• with the proviso that R1 is not imidazolyl, oxazolyl or 1,2,4-triazolyl;
• Ar is
• wherein →indicates the point of attachment to the pyridine ring;
• each R2 is independently selected from the group consisting of (C1-C4)alkyl, OR4, (C1-C4)alkoxy(C1-C4)alkyl, halo(C1-C4)alkyl, cyano and halo;
• n is 0 to 4;
• m is 0 to 7;
• p is 0 to 3;
• R3 is selected from the group consisting of hydrogen, (C1-C4)alkyl, OR4, (C1-C4)alkoxy(C1-C4)alkyl, halo(C1-C4)alkyl, cyano and halo;
• R4 is selected from the group consisting of hydrogen, (C1-C4)alkyl, halo(C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkyl, (C3-C6)cycloalkyl, (C3-C6)cycloalkyl(C1-C4)alkyl, Het1-, and Het1(C1-C4)alkyl-;
• and
• Het1 is a saturated 5- or 6-membered heterocyclic ring comprising one oxygen atom.