IUPAC Name: sodium 4-[4-[(2Z)-2-(2-oxonaphthalen-1-ylidene)hydrazinyl]phenyl]diazenylbenzenesulfonic acid Synonyms: Cloth Scarlet, Merpacyl Red L, Silk Scarlet GL, Benzyl Red G, Polan Red BR, Silk Red B, Fast Silk Red TR, Red L, Azo Silk Red 3B, Silk Red 3B, Acid Red 151, Amacid Neutral Red BW, Calcocid Milling Red 3R, C.I. Acid Red 151, Tertracid Milling Scarlet GF, EINECS 229-029-9, NSC 47723, C.I. Acid Red 151, monosodium salt, C.I. 26900, LS-31978