J acid Chemical Properties

Density 

1.4338 (rough estimate)

vapor pressure 

0Pa at 25℃

refractive index 

1.6500 (estimate)

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

solubility 

Slightly soluble in water

pka

-0.28±0.40(Predicted)

form 

powder

color 

yellow

Water Solubility 

5g/L at 20℃

InChIKey

KYARBIJYVGJZLB-UHFFFAOYSA-N

LogP

-1.39

CAS DataBase Reference

87-02-5(CAS DataBase Reference)

EPA Substance Registry System

7-Amino-4-hydroxy-2-naphthalenesulfonic acid (87-02-5)

Safety Information

Hazard Codes 

C

Risk Statements 

34

Safety Statements 

26-27-36/37/39

RIDADR 

UN 2585 8/PG 3

WGK Germany 

1

RTECS 

QK1295500

F 

21

HazardClass 

8

PackingGroup 

III

HS Code 

2922190090

Toxicity

LD50 oral in rat: 11500mg/kg

MSDS

• Language:English Provider:SigmaAldrich

J acid Usage And Synthesis

Chemical Properties

Gray needles, white when pure. Soluble in hot water; sparingly soluble in cold water. 2-Amino-5-hydroxynaphthalene-7-sulfonic acid [87-02-5]. (7-amino-4-hydroxynaphthalene-2-sulfonic acid), J acid, C10H9NO4S, Mr 239.2, is only slightly soluble (0.1 %) in cold water but readily soluble at 100℃. The alkalimetal salts are readily soluble in water. Diazo compounds are normally coupled with J acid under alkaline conditions with reaction in the 6-position (ortho to hydroxyl); however, under acid conditions, coupling can occur in the 1- position. Reaction with bisulfite gives 4,7-dihydroxynaphthalene-2-sulfonic acid. The N-acylation, Nalkylation, and N-arylation reactions are important.

Uses

Azo dye intermediate.

Production Methods

A concentrated disodium salt solution of 2-aminonaphthalene-5,7-disulfonic acid is added to 72 % sodium hydroxide at 150 ℃. After heating to 187℃ over 10 h reaction is continued at this temperature for a further 8 h until completion of the reaction is indicated by giving equivalent diazotization and coupling titers for a worked-up sample. Quenching, acidification, purging of sulfur dioxide, and filtration at 55 ℃ followed by washing with water at 50℃ result in an 88 % yield of paste. Purification by salting out the sodium salt from a hot alkaline solution gives a 90 % recovery of the product as gray crystals. An improved process with 90 % yield is claimed by feeding the concentrated 2-aminonaphthalene-5,7-disulfonic acid liquor and the caustic liquor simultaneously into the fusion reactor to maintain more stable conditions.

Definition

ChEBI: 7-amino-4-hydroxy-2-naphthalenesulfonic acid is an aminonaphthalenesulfonic acid that is 2-naphthalenesulfonic acid substituted by an amino group at position 7 and a hydroxy group at position 4 respectively. It has a role as a metabolite. It is an aminonaphthalenesulfonic acid and a member of naphthols.

Flammability and Explosibility

Not classified

J acid(87-02-5)Related Product Information

• 5,5'-Dihydroxy-2,2'-dinaphthylamine-7,7'-disulphonic acid
• CHLOROPHOSPHONAZO III
• Glycine
• Folic acid
• 4-Amino-benzenesulfonic acid monosodium salt
• Sulfamic acid monosodium salt
• Ammonium sulfamate
• Citric acid
• Ethyl 2-(Chlorosulfonyl)acetate
• Molasses
• 2-Naphthol
• ALTRENOGEST
• Nickel bis(sulphamidate)
• Sulfamic acid
• Naphthalene
• 1-Naphthol
• Stearic acid
• 7-Anilino-4-hydroxy-2-naphthalenesulfonic acid