abstract |
The invention provides compounds of formula (I), or a pharmaceutically acceptable salt thereof, wherein Ar 1 represents a group (II), (III), (IV) or (V), and A, Ar 2 , n, R 1 , R 2 , R 3 , R 4 and R 5 are as defined in the specification; a process for their preparation; pharmaceutical compositions containing them; and their use in therapy. |