Description

2-Naphthalenesulfonic Acid, 7-Amino-4-Hydroxy-3-[(4-Methoxy-2-Sulfophenyl)Azo]-, Disodium Salt 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 reactive dyes, particularly for polyamide fibers like nylon and wool. This compound is essential for manufacturers in the textile, leather, and specialty ink industries seeking to produce high-quality, colorfast products.

Application

• Primary Intermediate for Acid Dyes: A crucial building block in the synthesis of acid dyes used for coloring nylon, wool, silk, and other polyamide fibers.
• Reactive Dye Synthesis: Used in the production of reactive dyes that form covalent bonds with cellulose fibers like cotton, ensuring excellent wash-fastness.
• Leather Dyeing: Employed in the formulation of dyes for the leather tanning and finishing industry to achieve consistent and durable coloration.
• Inkjet and Specialty Inks: Serves as a colorant component in the manufacture of high-performance inks for digital textile printing and other industrial marking applications.
• Paper Coloring: Used in the production of dyes for specialty papers where bright, lightfast colors are required.
• Biological Staining: Potential use as a staining agent or intermediate in the preparation of biological stains for microscopy and diagnostic applications.

Basic Information

Product Name	2-Naphthalenesulfonic Acid, 7-Amino-4-Hydroxy-3-[(4-Methoxy-2-Sulfophenyl)Azo]-, Disodium Salt
CAS No.	42972-22-5
Molecular Formula	C17H13N3O8S2Na2
Molecular Weight	489.41 g/mol
Synonyms	Acid Red 337; C.I. 17200; 7-Amino-4-hydroxy-3-[(4-methoxy-2-sulfophenyl)azo]naphthalene-2-sulfonic acid disodium salt; Disodium 7-amino-4-hydroxy-3-[(4-methoxy-2-sulfophenyl)azo]naphthalene-2-sulfonate; Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-((4-methoxy-2-sulfophenyl)azo)-, disodium salt; Azo dye intermediate AR337; C.I. Acid Red 337
EINECS	Contact for details

Quality Control

Our production of this dye intermediate adheres to strict quality management systems. Every batch undergoes comprehensive analytical testing, including HPLC for purity and identity confirmation, to ensure it meets exacting specifications for use in sensitive dye synthesis. Certificates of Analysis (COA) documenting key parameters such as assay, impurity profile, and solubility are provided to guarantee batch-to-batch consistency and supply chain reliability.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from strong oxidizing agents and incompatible materials. The product is moisture-sensitive; ensure containers are kept sealed when not in use to prevent absorption of atmospheric humidity.

Specification

Item	Specification
Appearance	Dark red to brown powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Water Content	≤ 5.0%
Solubility (in Water)	Clear solution
Heavy Metals (as Pb)	≤ 20 ppm
Related Substances (HPLC)	Individual impurity ≤ 1.0%; Total impurities ≤ 3.0%

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