Patent ID: 8334305

Claim:
A compound of Formula (I) or a pharmaceutically acceptable salt thereof: wherein: R 1 is hydrogen; R 2 is 5-(hydroxymethyl)-adamantan-2-yl; R 4 is hydrogen; and —X 1 —X 2 —X 3 —R 3 is cyclohexylmethoxy, 2-(pyridin-2-yl)-ethoxy, 2-[1-(isopropylcarbamoyl)-piperidin-4-yl]-ethoxy, 2-[1-(cyclopropylsulfonyl)-piperidin-4-yl]-ethoxy, 2-[1-(3-hydroxy-2,2-dimethylpropionyl)piperidin-4-yl]-ethoxy, 4-methyl-phenyl, phenoxy, or 1-methyl-n-butoxy.