Benzenesulfinic Acid Sodium Salt (CAS 873-55-2): Properties, Production, and Industrial Applications

Editor:Jinli Chemical │ Release Time:2026-07-22 

Benzenesulfinic acid sodium salt, also known as sodium benzenesulfinate, is a white crystalline organosulfur compound with the molecular formula C6H5SO2Na and CAS number 873-55-2. As a key sulfinate intermediate, it plays a central role in modern organic synthesis, serving industries ranging from pharmaceuticals and dyes to polymer processing and electroplating.

1. Chemical Identity and Basic Properties

Benzenesulfinic acid sodium salt is the sodium salt of benzenesulfinic acid, in which the sulfinate group (-SO2Na) is attached directly to a benzene ring. It typically presents as a white to off-white crystalline powder with a molecular weight of approximately 164.16 g/mol, an EINECS number of 212-842-8, and an MDL number of MFCD00013135. The compound is highly soluble in water, which is a major reason it is favored in aqueous-phase organic reactions and industrial formulations.

PropertyValue
CAS Number873-55-2
Molecular FormulaC6H5NaO2S
Molecular Weight164.16 g/mol
AppearanceWhite crystalline powder
EINECS Number212-842-8
SolubilityReadily soluble in water

2. Technical Specifications

Product quality for this intermediate is generally judged against purity, moisture content, and residual salt levels, since trace impurities can interfere with downstream synthesis. A representative industrial-grade specification, consistent with what is offered on the Jinli Chemical product page for Benzenesulfinic acid sodium salt, is summarized below.

Check PointUnitSpecification
Appearance-White Crystalline Powder
Purity% min98
pH-7-10
Water Solution (2%)-Clear
Moisture% max1.0
Sodium Chloride% max1.0
Sodium Sulfate% max1.0
Sodium Carbonate% max0.05
Heavy Metalppm max10

3. Role in Organic Synthesis

Chemically, the sulfinate anion is a versatile nucleophile and mild reducing agent, which explains why this compound shows up across so many synthetic routes. Its most cited uses include:

  • Sulfone synthesis — reacting with alkyl or aryl halides to form organic sulfones, often carried out in alcohol or diol solvent systems.
  • Copper-catalyzed cross-coupling — combined with boronic acids to build aryl sulfones under mild catalytic conditions.
  • Reduction reactions — used to reduce sulfonyl chlorides to sulfinic acid derivatives, and to assist in reducing aromatic nitro groups and disulfide linkages.
  • Heterocycle construction — applied as a traceless linker in solid-phase synthesis routes toward pyrazolines, isoxazolines, dihydropyrimidinones, and related heterocyclic scaffolds.

4. Industrial Applications

Beyond laboratory-scale synthesis, benzenesulfinic acid sodium salt is consumed at industrial volume across several downstream sectors:

SectorTypical Use
PharmaceuticalsSynthetic intermediate and reducing agent in active pharmaceutical ingredient (API) manufacturing
Dyes and PigmentsReducing agent that helps regulate color saturation and dye stability
Polymer ProcessingAdhesion enhancer and modifier for polyamide, epoxy, and phenolic resin systems
Electroplating & PhotographyPhoto-reducing agent used in photosensitive material and plating processes
Coatings & AdhesivesAdditive for inks, nail polish, and adhesive formulations

5. Handling, Storage, and Safety Notes

Although generally stable under normal storage conditions, benzenesulfinic acid sodium salt can decompose when exposed to extreme heat or strong oxidizing agents, and it may cause irritation to skin and eyes on direct contact. Standard practice is to keep containers tightly sealed, store the material in a cool, dry area away from oxidizers, and use appropriate personal protective equipment during handling. A safety data sheet should always be consulted prior to industrial use.

6. Related Intermediates from Jinli Chemical

Buyers sourcing benzenesulfinic acid sodium salt often require related sulfonyl and sulfinate intermediates for the same production line. Jinli Chemical's Intermediates Series includes several closely related products:

You can browse the complete listing on the Intermediates Series product category page, or view the full Jinli Chemical product catalog.

7. About Jinli Chemical

Jiaxing Jinli Chemical Co., Ltd. is a China-based manufacturer specializing in blowing agents, plasticizers, chemical intermediates, and disinfectant products. The company supplies benzenesulfinic acid sodium salt and related sulfinate/sulfonyl intermediates to customers across the pharmaceutical, dye, polymer, and fine chemical industries. To learn more about production capabilities and quality systems, visit the Company Profile page, or review ongoing R&D initiatives on the Technology page. Industry updates and product news are posted regularly under Industry News.

For inquiries, bulk quotations, or technical documentation on benzenesulfinic acid sodium salt, reach out through the Contact page, or call the company hotline at 0086-573-85580888.

Benzenesulfinic Acid Sodium Salt