129477-58-3 2-Piperazinecarboxylic acid, 1,4-bis(3,4,5-trimethoxybenzoyl)-, ethyl ester Ethyl 1,4-bis(3,4,5-trimethoxybenzoyl)-2-piperazinecarboxylate N,N'-Di-(3',4',5'-trimethoxybenzoyl)-2-ethoxycarbonylpiperazine