1-Piperazinecarboxylic acid, 4-(2-(ethoxycarbonylimino)ethyl)-, ethyl ester 23111-69-5 5-23-01-00264 (Beilstein Handbook Reference) BRN 0813314 Ethyl 4-(2-(ethoxycarbonylimino)ethyl)-1-piperazinecarboxylate