Synonyms: Mesoxalicacid, (p-chlorophenyl)hydrazone, diethyl ester (6CI); Mesoxalic acid, diethylester, (p-chlorophenyl)hydrazone (7CI); Mesoxalic acid, diethyl ester,2-[(p-chlorophenyl)hydrazone] (8CI); Propanedioic acid,[(4-chlorophenyl)hydrazono]-, diethyl ester (9CI); NSC 527461