2-Formyl-1,4-benzenedisulfonic acid disodium salt
[CAS# 51818-11-2]

Identification

• Classification: Chemical reagent >> Organic reagent >> Sulfonate / sulfinate
• Name: 2-Formyl-1,4-benzenedisulfonic acid disodium salt
• Synonyms: Disodium 2-formyl-1,4-benzenedisulfonate
• Molecular Formula: C₇H₄O₇S₂^.₂Na
• Molecular Weight: 310.21
• CAS Registry Number: 51818-11-2
• EC Number: 686-015-9
• SMILES: C1=CC(=C(C=C1S(=O)(=O)[O-])C=O)S(=O)(=O)[O-]

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319
• Precautionary Statements: P264-P264+P265-P280-P302+P352-P305+P351+P338-P321-P332+P317-P337+P317-P362+P364

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315

Discovory and Applicatios

2-Formyl-1,4-benzenedisulfonic acid disodium salt is an aromatic compound characterized by a benzene ring substituted with two sulfonic acid groups at the 1 and 4 positions and an aldehyde group at the 2 position. The sulfonic acid groups are neutralized with sodium, forming a disodium salt that enhances the compound’s solubility in water. This chemical structure makes it highly polar and capable of interacting with aqueous systems, which is valuable in various industrial and research applications.

The compound is primarily used as a building block in organic synthesis, especially for the preparation of dyes, chelating agents, and other functionalized aromatic derivatives. Its aldehyde functional group is reactive toward nucleophilic addition and condensation reactions, enabling the formation of Schiff bases, imines, and other derivatives that can be incorporated into more complex molecular frameworks. The disulfonic acid moieties improve the water solubility of reaction intermediates and final products, which is particularly advantageous in aqueous-phase chemistry.

In industrial applications, 2-Formyl-1,4-benzenedisulfonic acid disodium salt serves as a precursor in the synthesis of sulfonated dyes, which are used in textiles, inks, and analytical chemistry. Its high polarity and reactivity allow for functional modifications, producing derivatives with desired color properties and solubility characteristics. Additionally, the compound can be employed in the preparation of polymer additives, where sulfonic acid groups confer ionic interactions and improved dispersibility in aqueous or polar media.

From a chemical perspective, the aldehyde group at the 2 position is highly electrophilic, making it suitable for reactions with amines, hydrazines, and other nucleophiles. The resulting adducts can be used to construct chelating ligands or fluorescent probes. The disulfonate form enhances compatibility with water-based formulations, which is important for environmentally friendly chemical processes and applications requiring minimal organic solvents.

Handling and storage of 2-Formyl-1,4-benzenedisulfonic acid disodium salt require consideration of its chemical stability. The aldehyde group may undergo oxidation under prolonged exposure to air or light, and it should be stored in a dry, cool environment, typically in airtight containers. The compound is generally stable in aqueous solutions at neutral pH, though prolonged storage may necessitate buffering or protection from strong oxidants.

Overall, 2-Formyl-1,4-benzenedisulfonic acid disodium salt is a versatile intermediate in chemical synthesis. Its combination of an electrophilic aldehyde group and water-solubilizing sulfonate groups provides both reactivity and compatibility with aqueous systems, enabling its use in dyes, chelating agents, polymers, and other functional materials.

References

Finar IL (2013) Organic Chemistry, Volume 1: Principles and Mechanisms 6th Edition, Pearson Education, 345–347

Friedel G, Crafts J (1877) Sur la sulfonation des composés aromatiques et sur les réactions de substitution électrophile. Comptes Rendus 85 1131–1135

Smith M, March J (2007) March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure 6th Edition, Wiley, 1010–1015.