| abstract |
The present invention relates to a piperazine derivative represented by formula (1) wherein n is an integer from 1 to 8; R1 represents hydrogen or C1-10 alkyl; A represents CH or nitrogen; Ar1 represents phenyl or substituted phenyl; and Y represents a group represented by the formula Y1 - Y2 - Ar2 or Y3 - Y4 (Ar5) - Ar6) or a pharmaceutically acceptable salt of the derivative. The novel piperazine derivative has antagonistic activity of the MC4 receptor. |