Peri acid

Dark green powder. 1-Aminonaphthalene-8-sulfonic acid [82- 75-7]. (8-aminonaphthalene-1-sulfonic acid), Peri acid, C10H9NO3S, Mr 223.24, crystallizes as the monohydrate and is sparingly soluble even in boiling water. The sodium salt is also sparingly soluble in water. Caustic fusion at 200℃ produces 8-amino-1- naphthol, whereas slow hydrolysis with 10 % sodium hydroxide at 220 – 260℃ yields 1,8- dihydroxynaphthalene. Sulfonation with cold 10 % oleum produces 1-aminonaphthalene-4,8- disulfonic acid, whereas hot concentrated sulfuric acid results in slow isomerization into naphthionic acid.

용도Intermediate of dyestuff. Dehydration with phosphorus oxychloride yields naphthosultam, and diazotization followed by hydrolysis results in naphthosultone, the intermediate for 1- hydroxynaphthalene-8-sulfonic acid. Diazotization followed by a Sandmeyer cyanide reaction gives 8-cyanonaphthalene-1-sulfonic acid, one of the most industrially important Sandmeyer reaction products because the nitrile forms the lactam, naphthostyril [130-00-7], upon treatment with concentrated alkali at 185℃. Hydrolysis of naphthostyril with dilute alkali yields 8-aminonaphthalene-1-carboxylic acid, which is the key intermediate for production of anthanthrone vat dyes via 1,10 -binaphthyl8,80 -dicarboxylic acid.