1,4-Benzenedicarboxylic acid, 2-((2-amino-8-hydroxy-6-sulfo-1-naphthalenyl)azo)-, diethyl ester, monosodium salt 73309-51-0 EINECS 277-378-0 Sodium diethyl 2-((2-amino-8-hydroxy-6-sulphonatonaphthyl)azo)terephthalate