1,4-Piperazinediacetic acid, alpha-(2-oxo-2-phenylethyl)-, 4-ethyl ester 4-Ethyl alpha-(2-oxo-2-phenylethyl)-1,4-piperazinediacetate 40513-10-8 alpha-(Ethoxycarbonylmethyl-4 piperazino-1) beta-benzoyl propionique acide [French]