2-Butenoic acid, 4,4'-(2-ethyl-1,4-piperazinediyl)bis(4-oxo-, diethyl ester, (Z,Z)- 4,4'-(2-Ethyl-1,4-piperazinediyl)bis(4-oxo)-2-butenoic acid diethyl ester 84930-22-3 Compound NG