Description

4-Hydroxy-3-Methyl-5-Nitrobenzenesulphonic Acid is a highly functionalized aromatic sulphonated intermediate featuring hydroxyl, methyl, nitro, and sulphonic acid groups—enabling selective coupling, diazotization, and metal-complex formation. Its structural precision and strong electron-withdrawing character make it a critical building block for high-performance dyes, pigments, and specialty agrochemicals requiring stringent batch-to-batch reproducibility. This compound is essential for R&D laboratories and manufacturing facilities in the colorants, pharmaceutical intermediates, and fine chemical synthesis sectors.

Application

• Azo dye synthesis — particularly for acid and metallized dyes used in textile and leather coloring
• Intermediate in the production of reactive dyes with enhanced wash-fastness and light-fastness
• Building block for nitroaromatic pharmaceutical intermediates, including antimicrobial and anti-inflammatory precursors
• Chelating agent component in specialty catalysts and metal-complex dyes for inkjet and digital printing inks
• Functional monomer in sulfonated polymer synthesis for ion-exchange membranes and fuel cell applications
• Reagent in analytical chemistry for spectrophotometric determination of metal ions (e.g., Fe³⁺, Cu²⁺)

Basic Information

Product Name	4-Hydroxy-3-Methyl-5-Nitrobenzenesulphonic Acid
CAS No.	85895-88-1
Molecular Formula	C7H7NO6S
Molecular Weight	233.20 g/mol
Synonyms	5-Nitro-2-hydroxy-4-methylbenzenesulfonic acid; 4-Hydroxy-3-methyl-5-nitrobenzenesulfonic acid; HMBNSA; 2-Hydroxy-4-methyl-5-nitrobenzenesulfonic acid; NSC 153915; 5-Nitro-o-cresol-3-sulfonic acid; 3-Sulfo-5-nitro-o-cresol; 5-Nitro-2-hydroxy-p-toluenesulfonic acid
EINECS	284-560-3

Quality Control

Our products undergo rigorous quality testing to ensure compliance with industry standards. Certificates of Analysis (COA) are available upon request. All batches conform to ISO 9001-certified manufacturing protocols and meet specifications aligned with ACS Reagent Grade and technical-grade requirements for fine chemical intermediates. Stability-indicating methods (HPLC, titration, IR) are applied to verify identity, assay, and impurity profiles.

Storage

Preserve in a tightly closed container, protected from light. Store at room temperature (15–25°C) in a dry, well-ventilated area. Due to its hygroscopic nature, minimize exposure to ambient humidity; use desiccant-lined secondary packaging for long-term storage.

Specification

Item	Specification
Appearance	Off-white to light yellow crystalline powder
Assay (by titration)	≥ 98.0%
Moisture (Karl Fischer)	≤ 1.5%
Heavy Metals (as Pb)	≤ 10 ppm
Residue on Ignition	≤ 0.1%
Identification (IR)	Conforms to reference standard
Identification (HPLC)	Retention time matches certified reference material

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