4-Amino-1,3-benzenedisulfonic acid

CAS NO.：137-51-9
Empirical Formula: C6H7NO6S2
Molecular Weight: 253.25
MDL number: MFCD00035903
EINECS: 205-299-3
SAFETY DATA SHEET (SDS)
Update Date: 2025-08-08 17:45:00

What is 4-Amino-1,3-benzenedisulfonic acid?

The Uses of 4-Amino-1,3-benzenedisulfonic acid

4-Amino-1,3-benzenedisulfonic Acid is used as a reagent in the synthesis of arylazopyridoxal phosphate and phosphonate derivatives as P2 receptor antagonists.

Production Methods

4-Amino-1,3-benzenedisulfonic acid is freely soluble in water and ethyl alcohol. It is prepared by sulfonating 4-aminobenzenesulfonic acid with oleum at 20 ℃ and130 ℃ (4 – 6.5 h), draining the sulfonation mixture into water under pressure, adding lime at 70 – 75 ℃, separating the resulting gypsum, precipitating the calcium ions with soda, removing the calcium carbonate formed, and concentrating the sodium salt solution by evaporation. Yield 90 – 91%

Flammability and Explosibility

Non flammable

Properties of 4-Amino-1,3-benzenedisulfonic acid

Melting point:	>259°C (dec.)
Boiling point:	497.45℃[at 101 325 Pa]
Density	1.844±0.06 g/cm3(Predicted)
vapor pressure	0Pa at 25℃
storage temp.	Keep in dark place,Sealed in dry,Room Temperature
solubility	Aqueous Acid (Slightly), DMSO (Slightly), Methanol (Slightly), Water (Slightly)
form	Solid
pka	-0.93±0.48(Predicted)
color	White to Grey
Water Solubility	4.3g/L at 21℃
Stability:	Hygroscopic
CAS DataBase Reference	137-51-9(CAS DataBase Reference)
EPA Substance Registry System	1,3-Benzenedisulfonic acid, 4-amino- (137-51-9)

Safety information for 4-Amino-1,3-benzenedisulfonic acid

Signal word	Danger
Pictogram(s)	Corrosion Corrosives GHS05 Exclamation Mark Irritant GHS07
GHS Hazard Statements	H302:Acute toxicity,oral H314:Skin corrosion/irritation
Precautionary Statement Codes	P261:Avoid breathing dust/fume/gas/mist/vapours/spray. P280:Wear protective gloves/protective clothing/eye protection/face protection. P310:Immediately call a POISON CENTER or doctor/physician. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.