Patent ID: 8592428

Claim:
A compound, or a pharmaceutically acceptable salt thereof, presented in Formula (I): wherein R 1 represents a group selected from the group consisting of: a lower alkylsulfonyl group; lower alkyl groups substituted with a hydroxy or lower alkoxy group; a lower alkoxy group substituted with a hydroxy group; and a group of Formula (II): wherein R 3 and R 4 independently represent a hydrogen atom or a lower alkyl group optionally substituted with a hydroxy group, or R 3 and R 4 together with a nitrogen atom to which they are attached represent a four- to seven-membered nitrogen-containing aliphatic ring; R 2 represents a hydrogen atom; R 20 is a branched lower alkyl group substituted with a hydroxy group or a group of Formula (III): wherein R 5 and R 6 independently represent a hydrogen atom, or a lower alkyl group, or R 5 and R 6 together with a nitrogen atom to which they are attached represent a four- to seven-membered nitrogen-containing aliphatic ring; m represents an integer of from 1 to 3; n represents zero or 1; and Formula (IV): represents a heteroaryl group selected from the group consisting of: pyridinyl, pyrazinyl, and pyrazolyl.