The present invention provides a piperazine compoundrepresented by Formula (I) or a salt thereof,(see formula I)whereinX represents CH or an N atom；R1 represents C1-6 alkyl；R2 represents C1-6 alkyl that may have one or moresubstituents, C2-6 alkenyl that may have one or more substituents,-(C=O)-N(R3) (R4), or -(C=O)-OR5,R3 and R4 are the same or different, and eachrepresents hydrogen or C1-6 alkyl that may have one or moresubstituents； or R3 and R4, taken together with a nitrogen atom towhich R3 and R4 are attached, may form a saturated heterocyclicgroup； andR5 represents hydrogen or C1-6 alkyl that may have oneor more substituents or aralkyl.
