"Piperazine compound capable of inhibiting prostaglandin d synthase and its uses, as well as pharmaceutical composition, prostaglandin d synthase inhibitor and agent comprising said compound"
This invention relates to a piperazine compound represented by Formula (I), wherein R 1 is C 1-6 alkyl; R 2 is hydroxy, C 1-6 alkyl that may have one or more substituents, -(C=O)-N(R 3 )(R 4 ), or -(C=O)-OR 5 ; R 3 and R 4 are the same or different, and each represents hydrogen or C 1-6 alkyl that may have one or more substituents, or R 3 and R 4 , taken together with a nitrogen atom to which R 3 and R 4 are attached, may form a saturated heterocyclic group; R 5 is hydrogen or C 1-6 alkyl that may have one or more substituents; and n is 1 or 2; or a salt thereof.