Peri acid Property

Melting point:

>350°C

Boiling point:

220°C (rough estimate)

Density 

1.3588 (rough estimate)

refractive index 

1.6500 (estimate)

pka

pK1: 5.03 (25°C)

form 

powder to crystal

color 

Light yellow to Brown

Water Solubility 

0.2g/L(21 ºC)

Merck 

14,6405

BRN 

983230

CAS DataBase Reference

82-75-7(CAS DataBase Reference)

EPA Substance Registry System

1-Naphthalenesulfonic acid, 8-amino- (82-75-7)

Safety

Hazard Codes 

C

Risk Statements 

34

Safety Statements 

26-27-36-45

TSCA 

Yes

HS Code 

29214500

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P405Store locked up.

Peri acid Chemical Properties,Usage,Production

Chemical Properties

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.

Uses

Intermediate 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.

Production Methods

Naphthalene is converted to naphthalene-1-sulfonic acid. The crude sulfonation product is diluted with sulfuric acid, and 67.5 % nitric acid is added slowly at 30℃ to give the 5- and 8-nitro derivatives. The products are converted to the readily soluble magnesium salts by addition of a slurry of dolomite. The reaction mixture is neutralized with chalk and filtered hot. The filtrate is run into a suspension of iron powder in boiling water, which is kept slightly acidic with sulfuric acid. When reduction is complete, dissolved iron is precipitated by addition of magnesia, the iron residues are filtered off while hot, and the resulting liquor is acidified to pH 4.5 with sulfuric acid to give 99 % pure Peri acid in 48 % yield. The filtrates are further acidified to precipitate crude Laurent’s acid. This may be purified via its magnesium salt to give a 17 % yield of pure 1,5-isomer.