The Peri acid with CAS registry number of 82-75-7 is also known as 1-Aminonaphthalene-8-sulfonic acid. The IUPAC name is 8-Aminonaphthalene-1-sulfonic acid. It belongs to product categories of Intermediates of Dyes and Pigments. Its EINECS registry number is 201-437-1. In addition, the formula is C₁₀H₉NO₃S and the molecular weight is 223.25. This chemical is a white needle crystal and should be sealed in dry, dark place.

Physical properties about Peri acid are: (1)ACD/LogP: 0.42; (2)ACD/LogD (pH 5.5): -3.06; (3)ACD/LogD (pH 7.4): -3.08; (4)ACD/BCF (pH 5.5): 1; (5)ACD/BCF (pH 7.4): 1; (6)ACD/KOC (pH 5.5): 1; (7)ACD/KOC (pH 7.4): 1; (8)#H bond acceptors: 4; (9)#H bond donors: 3; (10)#Freely Rotating Bonds: 2; (11)Index of Refraction: 1.713; (12)Molar Refractivity: 58.27 cm³; (13)Molar Volume: 148.6 cm³; (14)Surface Tension: 72.1 dyne/cm; (15)Density: 1.502 g/cm³.

Preparation of Peri acid: it is prepared by reaction of refined naphthalene. The product is obtained by sulfonation, nitration, neutralization with magnesium carbonate, iron reduction, acid analysis and filtration. In the reaction, reaction mixture is concentrated to a certain concentration, cooled to 30-32 °C and filtered. Then the filtrate is partial acidified with sulfuric acid at the temperature of 40-45 °C for 12 hours. At last, the filtrate is dealed with acid to get the product.

Uses of Peri acid: it is used as dye intermediate and is used to produce naphth[1,8-cd][1,2]oxathiol-2,2-dioxide. The reaction occurs with reagents NaNO₂, aq. HCl and solvent H₂O with other condition of heating for 1 hour. The yield is about 92%.

When you are using this chemical, please be cautious about it. As a chemical, it can cause burns. During using it, wear suitable protective clothing. After using it, take off immediately all contaminated clothing. If contact with eyes accidently, rinse immediately with plenty of water and seek medical advice. In case of accident or if you feel unwell seek medical advice immediately.

You can still convert the following datas into molecular structure:
1. Canonical SMILES: C1=CC2=C(C(=C1)N)C(=CC=C2)S(=O)(=O)O
2. InChI: InChI=1S/C10H9NO3S/c11-8-5-1-3-7-4-2-6-9(10(7)8)15(12,13)14/h1-6H,11H2,(H,12,13,14)
3. InChIKey: CYJJLCDCWVZEDZ-UHFFFAOYSA-N