Aminonaphthalenesulfonic acids are compounds with the composition C<sub>10</sub>H<sub>6</sub>(NH<sub>2</sub>)(SO<sub>3</sub>H), being derived from naphthalene (C<sub>10</sub>H<sub>8</sub>) substituted by an amino and sulfonic acid groups. These compounds are colorless solids. They are useful precursors to dyes.
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.