Sulfanilic Acid

• CAT Number: R053309
• CAS Number: 121-57-3
• Molecular Formula: C6H7NO3S
• Molecular Weight: 173.19
• Purity: ≥95%
• Synonyms: 4-Aminobenzenesulfonic Acid; 1-Aminobenzene-4-sulfonic Acid; 4-Aminophenylsulfonic Acid; 4-Sulfoaniline; Aniline-4-sulfonic Acid; Aniline-p-sulfonic Acid; NSC 7170; Sulphanilic Acid; p-Aminobenzenesulfonic Acid; p-Aminophenylsulfonic Acid; p-Sulfoani
• Storage: Store at -20°C
• IUPAC Name: 4-aminobenzenesulfonic acid
• InChI: InChI=1S/C6H7NO3S/c7-5-1-3-6(4-2-5)11(8,9)10/h1-4H,7H2,(H,8,9,10)
• InChIKey: HVBSAKJJOYLTQU-UHFFFAOYSA-N
• SMILES: C1=CC(=CC=C1N)S(=O)(=O)O

Sulfanilic acid (Cat No.: R053309) is an aromatic amine sulfonic acid with the molecular formula C₆H₇NO₃S. It features an aniline (phenylamine) group para to a sulfonic acid group on a benzene ring. Commonly used in the synthesis of azo dyes, optical brighteners, and pharmaceuticals, sulfanilic acid also serves as a key reagent in analytical chemistry, notably in the diazotization reaction for nitrite detection. It is water-soluble, stable, and plays a central role in coupling reactions due to its dual functional groups.