1-Aminonaphthalene-4-sulfonic acid

Aminonaphthalenesulfonic acids are compounds with the composition C₁₀H₆(NH₂)(SO₃H), being derived from naphthalene (C₁₀H₈) substituted by an amino and sulfonic acid groups. These compounds are colorless solids. They are useful precursors to dyes.

red 3, C.I. food red 7, C.I. food red 9, and C.I.

Notes: Peri-acid dehydrates to the sultam. Via the Bucherer reaction, heating periacid with anilinium salts gives the N-phenyl derivative, precursor to Acid Blue 113.

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