Description

Tetrasodium 4,5-Dihydroxy-3,6-Bis[(4-Methyl-2-Sulphonatophenyl)Azo]Naphthalene-2,7-Disulphonate is a high-purity, water-soluble azo dye intermediate of significant commercial importance. Its primary value lies in its role as a key precursor for synthesizing vibrant and stable acid dyes and food colorants. This compound is essential for manufacturers in the textile, leather, ink, and specialty chemical industries seeking to produce high-quality, color-fast products. The CAS number for this compound is 65271-28-5.

Application

• Primary Intermediate for Acid Dyes: A crucial building block for manufacturing a wide range of acid dyes used in coloring nylon, silk, wool, and modified acrylic fibers.
• Food Colorant Synthesis: Used in the production of certain synthetic food dyes (where permitted by regulation) due to its intense color properties and solubility.
• Leather Dyeing: Serves as an intermediate for dyes applied in the leather tanning and finishing industry to achieve consistent, deep shades.
• Ink & Pigment Manufacturing: Employed in the synthesis of pigments and dyes for inks used in packaging, printing, and specialty coatings.
• Paper Coloring: Used in the production of dyes for tinting paper and paper products.
• Biological Staining: Can be utilized as an intermediate for certain histological stains in laboratory settings.
• Research & Development: Serves as a standard or starting material in chemical research for developing new chromophores and functional dyes.

Basic Information

Item	Details
Product Name	Tetrasodium 4,5-Dihydroxy-3,6-Bis[(4-Methyl-2-Sulphonatophenyl)Azo]Naphthalene-2,7-Disulphonate
CAS No.	65271-28-5
Molecular Formula	C34H20N4Na4O16S4
Molecular Weight	960.78 g/mol
Synonyms	Acid Red 337 (disodium salt precursor); C.I. 17200; Tetrasodium 3,6-Bis[(4-methyl-2-sulfophenyl)azo]-4,5-dihydroxy-2,7-naphthalenedisulfonate; 4,5-Dihydroxy-3,6-bis[(4-methyl-2-sulfophenyl)azo]-2,7-naphthalenedisulfonic acid tetrasodium salt; Azo Dye Intermediate AR337; Food Black 2 related intermediate; Naphthalene sulfonic acid azo dye
EINECS	Contact for details

Quality Control

Our Tetrasodium 4,5-Dihydroxy-3,6-Bis[(4-Methyl-2-Sulphonatophenyl)Azo]Naphthalene-2,7-Disulphonate is produced under a stringent quality management system. Each batch is tested to ensure it meets precise specifications for purity, color strength, and solubility. Certificates of Analysis (COA) documenting key parameters such as assay (by HPLC), impurity profile, heavy metal content, and moisture are provided with every shipment to guarantee consistency and traceability for your manufacturing processes.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). This product is hygroscopic (moisture-sensitive); keep the container tightly sealed when not in use to prevent absorption of atmospheric moisture, which can affect purity and handling properties.

Specification

Item	Specification
Appearance	Dark red to brown powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Moisture (KF)	≤ 5.0%
Water Solubility	Clear solution at 1% w/v
pH (1% Solution)	7.0 - 9.0
Heavy Metals (as Pb)	≤ 20 ppm
Ash Content	Contact for details

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.