1-Aminonaphthalene-3-sulfonic acid [134- 54-3]. (4-aminonaphthalene-2-sulfonic acid), C10H9NO3S, Mr 223.24, is only sparingly soluble in water, but its alkali-metal salts are readily soluble. Sulfonation with 20 % oleum yields 1-aminonaphthalene-3,5-disulfonic acid, and heating with water under pressure gives 1- hydroxynaphthalene-3-sulfonic acid, which can also be obtained by diazotization and acid hydrolysis of 1-Aminonaphthalene-3-sulfonic acid.
1-Aminonaphthalene-3,8-disulfonic acid in dilute sodium hydroxide solution is pumped at 40℃ through a special reactor that effects contact with continuously produced sodium amalgam. The resulting liquor is used directly for production of 1- hydroxynaphthalene-3-sulfonic acid.
