PIPERAZINE DERIVATIVE

摘要

The object is to provide a compound which can specifically bind to an NR1/NR2B receptor and can be used as an antagonist of an NR2B receptor. It is found that a piperazine derivative represented by the formula (I) can specifically bind to an NR1/NR2B receptor and can be used as an antagonist of an NR2B receptor. Thus, disclosed is a compound represented by the formula (I), a pharmaceutically acceptable salt thereof, or a solvate of the compound or the pharmaceutically acceptable salt thereof. (I) wherein R1's independently represent a C1-C3 alkyl or the like; m represents an integer of 0 to 4; X represents -N(R4)-C(=O)-C(=O)-, -N(R4)-(CR5R6)p-C(=O)-, -N(R4)-C(=O)-(CR7R8)q- or -C(=O)-N(R4)-(CR7R8)q-; p and q independently represent an integer of 1 to 3; R4, R5, R6, R7 and R8 independently represent a hydrogen or a lower alkyl; A1 represents a benzoxazolinone or the like; and A2 represents a phenyl which may be substituted or the like.