1,2-Bis(3,5-dioxopiperazin-1-yl)ethane 1506-47-4 2,6-Piperazinedione, 4,4'-(1,2-ethanediyl)bis- (9CI) 2,6-Piperazinedione, 4,4'-ethylenedi- (8CI) AI3-52846 Icrf 154 Icrf-154 NSC 129942