Patent ID: 8461197

Claim:
A compound of the Formula B: or a pharmaceutically acceptable salt thereof, wherein: A 1 is hydrogen, deuterium, —CH 2 —C(O)OR 2′ or —CH(R 1′ )—C(O)OR 2′ ; R 1′ is C 1-6 alkyl, C 2-10 alkoxyalkyl, phenyl, —(C 1-3 alkyl)-(C 3-6 cycloalkyl), or C 3-6 cycloalkyl, wherein R 1′ is optionally substituted with C 1-3 alkyl, C 1-3 alkoxy, phenyl, —O—(CH 2 CH 2 O) n —CH 3 , wherein n is 1, 2, or 3; R 2′ is hydrogen; deuterium; —C 1-4 alkyl optionally substituted with phenyl; —(C 3-6 cycloalkyl) optionally substituted with phenyl or methyl; —CH 2 —(C 3-6 cycloalkyl) wherein the C 3-6 cycloalkyl is optionally substituted with phenyl; phenyl; or biphenyl; X 1 is hydrogen, deuterium, —C(O)-indanyl, —C(O)-indenyl, —C(O)-tetrahydronaphthyl, —C(O)—C 1-6 alkyl, —C(O)—C 1-6 alkenyl, —C(O)—C 1-6 alkynyl, —C(O)—C 1-3 alkyl optionally substituted with C 3-6 cycloalkyl, or —C(O)—C 3-6 cycloalkyl optionally substituted with C 1-6 alkyl, phenyl or naphthyl; and each Y is independently selected from hydrogen and deuterium, provided that: (i) when A 1 is hydrogen or deuterium, at least one Y is deuterium; and (ii) when X 1 is hydrogen or deuterium, each Y 2 is deuterium, and each Y 3 is deuterium, then A 1 is not hydrogen or deuterium.