C.I. Mordant Orange 1, monosodium salt (8CI); Benzoic acid, 2-hydroxy-5-(2-(4-nitrophenyl)diazenyl)-, sodium salt (1:1); sodium (3Z)-3-[(4-nitrophenyl)hydrazono]-6-oxocyclohexa-1,4-diene-1-carboxylate; (3E)-3-[(4-nitrophenyl)hydrazono]-6-oxocyclohexa-1,4-diene-1-carboxylic acid; 3-[(4-nitrophenyl)hydrazono]-6-oxocyclohexa-1,4-diene-1-carboxylic acid; 2-hydroxy-4-[(E)-(4-nitrophenyl)diazenyl]benzoate; sodium 2-hydroxy-5-[(E)-(4-nitrophenyl)diazenyl]benzoate