1-(5,6,7,8-Tetrahydro-1-naphthalenyl)piperazine (Z)-2-butenedioate 1-(5-Tetralyl)piperazine maleate 57537-09-4 Piperazine, 1-(5,6,7,8-tetrahydro-1-naphthalenyl)-, (Z)-2-butenedioate (1:1)