Patent ID: 8084623

Claim:
A compound of formula I: or a pharmaceutically acceptable salt thereof, wherein: m is 1; n is 1; Ar is: optionally substituted phenyl; R 1 is: C 3-6 alkyl; aryl-C 1-6 alkyl; C 3-6 cycloalkyl-C 1-6 alkyl; hetero-C 1-6 alkyl; halo-C 1-6 alkyl; or C 1-6 -alkyl-C 1-3 cycloalkyl-C 1-6 alkyl; R 2 is: hydrogen; or C 1-6 alkyl; and R a and R b each independently is: hydrogen; C 1-6 alkyl; C 1-6 alkoxy; halo; hydroxy; or oxo; or R a and R b together form a C 1-2 alkylene.