3,4-Diaminobenzenesulfonic acid Chemical Properties

Melting point:

-12 °C

Boiling point:

178-179 °C3 mm Hg(lit.)

Density 

0.936 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.441(lit.)

Flash point:

>230 °F

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

solubility 

hexane, toluene, ethanol and acetone: soluble

pka

-0.52±0.50(Predicted)

form 

Solid

color 

Dark Brown

Dielectric constant

4.5（30℃）

InChI

InChI=1S/C6H8N2O3S/c7-5-2-1-4(3-6(5)8)12(9,10)11/h1-3H,7-8H2,(H,9,10,11)

InChIKey

FKSRSWQTEJTBMI-UHFFFAOYSA-N

SMILES

C1(S(O)(=O)=O)=CC=C(N)C(N)=C1

CAS DataBase Reference

7474-78-4(CAS DataBase Reference)

EPA Substance Registry System

Benzenesulfonic acid, 3,4-diamino- (7474-78-4)

Safety Information

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36

WGK Germany 

1

RTECS 

VS1150000

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

3,4-Diaminobenzenesulfonic acid Usage And Synthesis

Uses

3,4-Diaminobenzenesulfonic Acid is a useful organic synthetic reagent and a sulfonate-aminium zwitterion.

Synthesis

The general procedure for the synthesis of 3,4-diaminobenzenesulfonic acid from o-phenylenediamine was as follows: first, the sulfonation mixture was prepared by dissolving 160 g (1.48 mol) of 1,2-diaminobenzene in 800 g (435 mL; 8.16 mol) of 95-97% sulfuric acid. Subsequently, the sulfonated mixture was divided into four portions and pumped into a continuous flow microreactor for the reaction. The microreactor consisted of a sequentially connected inlet module, five residence modules and an outlet module, each of which was maintained at a constant reaction temperature. Upon completion of the reaction, the sulfonation mixture was rapidly cooled with water at the reactor outlet to allow the sulfonation reaction products to precipitate in an ice-water bath. After filtration, the resulting white product was characterized by nuclear magnetic resonance (NMR). Based on 1H-NMR spectroscopy (400 MHz, DMSO-d6) analysis, no isomers were detected in all the products isolated in the experiments, confirming the formation of 3,4-diaminobenzenesulfonic acid and the absence of impurities. The yields of the products were influenced by the reaction temperature and residence time: 80% at 160 °C reaction temperature for 25 min, 89%, 90% and 100% at 180 °C reaction temperature for 5, 10 and 25 min, respectively.

References

[1] Patent: WO2012/74822, 2012, A1. Location in patent: Page/Page column 19-20
[2] Patent: EP2457886, 2012, A1. Location in patent: Page/Page column 9
[3] Patent: EP1400507, 2004, A1. Location in patent: Page 4; 5
[4] Tetrahedron, 2008, vol. 64, # 22, p. 5410 - 5415
[5] Patent: US2012/225863, 2012, A1. Location in patent: Page/Page column 40

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