Salt-Forming Reagent

1,2-Ethanedisulfonic Acid Dihydrate

CAS5982-56-9

1,2-Ethanedisulfonic acid dihydrate (CAS 5982-56-9) is the crystalline dihydrate of ethane-1,2-disulfonic acid, a strong diprotic sulfonic acid. It is the standard reagent for preparing edisylate (edisilate) salts of basic active pharmaceutical ingredients and is widely used in salt screening. KingPharm supplies research and production grades with a batch-specific certificate of analysis.

Chemical structure of 1,2-Ethanedisulfonic Acid Dihydrate
C2H6O6S2.2H2O · 226.23 g/mol
CAS No.
5982-56-9
Formula
C2H6O6S2.2H2O
Mol. weight
226.23 g/mol
Purity
96.0
Appearance
White to Gray Crystal

Product Description

1,2-Ethanedisulfonic acid dihydrate (C2H6O6S2·2H2O, MW 226.2) is a white to off-white crystalline solid. It carries two sulfonic acid groups on a two-carbon backbone and is supplied as the dihydrate, which is easier to weigh and handle than the anhydrous acid.

Both sulfonic acid groups are strongly acidic and fully protonate basic nitrogen atoms in drug molecules, giving edisylate salts. Depending on the base, it forms 1:1 salts with dibasic compounds (for example prochlorperazine edisylate) or 1:2 hemi-edisylate salts with monobasic compounds.

Compared with monosulfonic acids such as methanesulfonic acid, the diacid offers an additional stoichiometry option and can yield crystalline salts with different solubility, hygroscopicity and stability profiles, which makes it a useful counterion in salt and polymorph screening.

When purchasing, check assay, water content (consistent with the dihydrate), appearance and residual metals on the certificate of analysis. For stoichiometric calculations, use the dihydrate molecular weight rather than that of the anhydrous acid.

Chemical Specifications

Identifiers

CAS number 5982-56-9
Product name 1,2-Ethanedisulfonic Acid Dihydrate
Chinese name 1,2-乙二磺酸二水合物
IUPAC name ethane-1,2-disulfonic acid;dihydrate
Chinese synonyms 1,2-乙二磺酸水合物; 1,2-乙烷二磺酸二水合物
Molecular formula C2H6O6S2.2H2O
Molecular weight 226.23 g/mol
PubChem CID 57346009
InChIKey DSGUSEBCDAKBCM-UHFFFAOYSA-N
SMILES C(CS(=O)(=O)O)S(=O)(=O)O.O.O

Specification

Typical release specification for 1,2-Ethanedisulfonic Acid Dihydrate. Each batch is supplied with its own certificate of analysis; customer specifications can be discussed.
Test Specification Method
Appearance White to Gray Crystal 外观-4.1.3
Assay(T) 96.0 含量(滴定)
Water(KF) 17.0% 水分

Physical and chemical properties

Appearance White to Gray Crystal

Applications

1,2-Ethanedisulfonic acid dihydrate is mainly used as a counterion source in pharmaceutical salt formation.

Edisylate salt formation

Converts basic APIs into edisylate salts, as in prochlorperazine edisylate.

Salt and polymorph screening

Serves as a strong diacid counterion when screening salts for solubility, crystallinity and stability.

Analytical reference preparation

Used to prepare edisylate reference materials for counterion identification and assay methods.

Quality Documentation

The following documents can be provided for 1,2-Ethanedisulfonic Acid Dihydrate to support technical evaluation and purchasing. Documents are issued for the specific grade and batch supplied.

  • Certificate of Analysis (COA) Batch-specific test results against the specification.
  • Product specification The release specification with test items, limits and methods.
Request documents

Packaging, Storage & Transport

Available pack sizes 25 kg, 10 kg, 1 kg, 500 g, 100 g, 25 g

Read the current safety data sheet before handling. Packaging can be adapted to the order quantity and destination.

Frequently Asked Questions

How does edisylate differ from mesylate as a counterion?

Ethanedisulfonic acid has two sulfonic acid groups, so it can form 1:1 salts with dibasic compounds or 1:2 hemi-salts with monobasic compounds, whereas methanesulfonic acid forms only 1:1 salts with each basic site. The resulting salts often differ in crystallinity, solubility and hygroscopicity, so both are usually included in salt screening.

Should the water of hydration be considered in stoichiometry?

Yes. The dihydrate (MW 226.2) contains about 16% water by mass, so charging by the anhydrous molecular weight (about 190.2) under-doses the acid. Check the water content on the COA for each batch.

How should it be stored?

Keep the container tightly closed in a cool, dry place at room temperature, protected from moisture. The acid is irritating to skin, eyes and the respiratory tract; handle with gloves and eye protection.

What is the CAS number of 1,2-Ethanedisulfonic Acid Dihydrate?

The CAS Registry Number of 1,2-Ethanedisulfonic Acid Dihydrate is 5982-56-9.

What is the molecular formula and molecular weight of 1,2-Ethanedisulfonic Acid Dihydrate?

The molecular formula of 1,2-Ethanedisulfonic Acid Dihydrate is C2H6O6S2.2H2O, and its molecular weight is 226.23 g/mol.

What is 1,2-Ethanedisulfonic Acid Dihydrate used for?

1,2-Ethanedisulfonic acid dihydrate is mainly used as a counterion source in pharmaceutical salt formation.

Which quality documents are available for 1,2-Ethanedisulfonic Acid Dihydrate?

The following documents are available for 1,2-Ethanedisulfonic Acid Dihydrate: Certificate of Analysis (COA); Product specification. Contact KingPharm to request the documents for a specific batch.

How can I request a quotation for 1,2-Ethanedisulfonic Acid Dihydrate?

Send an inquiry for 1,2-Ethanedisulfonic Acid Dihydrate (CAS 5982-56-9) with the required quantity, target specification, destination country and any documentation requirements. KingPharm will confirm availability, packaging, lead time and price.

Request a Quote for 1,2-Ethanedisulfonic Acid Dihydrate

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Page last reviewed on by Leo Xiao.