1-Piperazinepropanoic acid, 4-(2-(9H-fluoren-9-yloxy)ethyl)-, (Z)-2-butenedioate (1:2) 1-Piperazinepropionic acid, 4-(2-(9-fluorenyloxy)ethyl)-, dimaleate 4-(2-(9-Fluorenyloxy)ethyl)-1-piperazinepropionic acid dimaleate 72461-61-1