Patent ID: 8901087

Claim:
A compound of Formula (I) or a pharmaceutically acceptable salt thereof: wherein: each R is independently H or C(O)CH 3 ; R 1 and R 2 are independently selected from the group consisting of: H, C 1-6 alkyl, C 2-6 alkenyl, C 1-6 alkoxy, —(CH 2 ) n -cyclopropyl and —(CH 2 ) n -cyclobutyl wherein n is 0, 1, 2, 3 or 4; or R 1 and R 2 may be joined together with the nitrogen atom to which they are attached to form azetidine, pyrrolidine, piperidine or isoxazolidine, said C 1-6 alkyl, C 2-6 alkenyl, C 1-6 alkoxy, —(CH 2 ) n -cyclopropyl, —(CH 2 ) n -cyclobutyl, azetidine, pyrrolidine, piperidine and isoxazolidine optionally substituted from one up to the maximum number of substituents with fluoro, hydroxy and methyl; R 3 is selected from the group consisting of: C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 3-6 cycloalkyl, aryl and heteroaryl, each optionally substituted from one up to the maximum number of substituents with fluoro and OH; R 4 is selected from the group consisting of: H, F, C 1-8 alkyl, C 2-8 alkenyl and C 2-8 alkynyl, each excluding hydrogen optionally substituted from one up to the maximum number of substituents with fluoro and OH; or R 3 and R 4 and the carbon atom to which they are attached may join together to form vinyl or a 3 to 7-membered carbocyclic or heterocyclic ring, said 3 to 7-membered carbocyclic or heterocyclic ring optionally containing a double bond and optionally substituted from one up to the maximum number of substituents with fluoro and OH; and R 5 is selected from H, F, OH and OC(O)CH 3 ; with the proviso that when R 4 is F then R 5 is other than OH and OC(O)CH 3 .