BENZENESULFINIC ACID Chemical Properties

Melting point:

84°C

Boiling point:

111.5°C (estimate)

Density 

1.365 (estimate)

refractive index 

1.5300 (estimate)

storage temp. 

under inert gas (nitrogen or Argon) at 2-8°C

pka

1.3(at 20℃)

form 

solid

BENZENESULFINIC ACID Usage And Synthesis

Definition

ChEBI: Benzenesulfinic acid is an organosulfinic acid. It is a conjugate acid of a benzenesulfinate.

Synthesis Reference(s)

Chemical and Pharmaceutical Bulletin, 35, p. 1770, 1987 DOI: 10.1248/cpb.35.1770

Purification Methods

The acid is purified by dissolving the Na salt in H2O, acidifying to Congo Red paper with HCl and adding a concentrated solution of FeCl3 whereby Fe sulfinate precipitates. Collect the salt, wash it with a little H2O, drain, suspend it in H2O and add a slight excess of 1.5M aqueous NaOH. The Fe(OH)3 precipitates, it is filtered off, the sulfinic acid in the aqueous solution is extracted with Et2O, the extract is dried (Na2SO4) and evaporated to give colourless crystals of benzenesulfinic acid m 84o which are stored under N2 in the dark, as it slowly oxidises in air to the sulfonic acid. [Beilstein 11 H 2, 11 I 3, 11 II 3, 11 III 3, 11 IV 3.]

BENZENESULFINIC ACID(618-41-7)Related Product Information

• ACID BLUE 80
• Cresol Red
• Sodium anthraquinone-2-sulfonate
• BCP
• ACID GREEN 27 (C.I. 61580)
• ACID VIOLET 34
• 2-CHLOROETHYL P-TOLUENESULFONATE
• Acid Green 25
• ACID BLUE 25
• ACID BLUE 40
• Bromochlorophenol Blue sodium salt
• THYMOL BLUE
• Mordant Blue 29
• REACTIVE BLUE 4
• REACTIVE BLACK 5
• ACID BLUE 41
• ANTHRAQUINONE-2,6-DISULFONIC ACID DISODIUM SALT
• Benzenesulfinic acid copper(II) salt hydrate, 97%,benzenesulfinic acid cupric salt