5-[4-[(2-Cyano-4-nitrophenyl)azo]phenyl]-2,8-dioxa-5-azanonanedioic acid dimethyl ester

methyl 7-[4-[(2-cyano-4-nitrophenyl)azo]phenyl]-3-oxo-2,4,10-trioxa-7-azaundecan-11-oate

2,4,10-Trioxa-7-azaundecan-11-oic acid, 7-[4-[(2-cyano-4-nitrophenyl)azo]phenyl]-3-oxo-, methyl ester