High Purity 5-Nitro-2-aminophenol Dye Intermediate CAS 121-88-0

5-Nitro-2-aminophenol (5-NAP) – Product Description

1. Product Overview

5-Nitro-2-aminophenol (5-NAP), also known as 2-Amino-5-nitrophenol or 2-Hydroxy-4-nitroaniline, is a substituted aromatic compound with the molecular formula C₆H₆N₂O₃ and a molecular weight of 154.12 g/mol. It is registered under CAS Number 121-88-0 and EINECS Number 204-503-8. This organic intermediate presents as light brown to yellowish-brown needle-like crystals or brown amorphous granules/powder, with a melting point range of 198–202°C (decomposes). 5-NAP is slightly soluble in water but readily soluble in ethanol, ether, acetone, benzene, and concentrated inorganic acids. As a versatile chemical building block, 5-NAP serves as a critical intermediate across multiple industrial sectors, including dye manufacturing, pharmaceutical synthesis, and specialty chemical production. Its well-characterized coordination geometry—octahedral with nitro groups occupying axial sites—makes it a compound of significant interest in both industrial applications and analytical chemistry research. The compound is commercially available in various purity grades, typically ranging from 90% to 95% or higher, with packaging options from small research quantities to bulk industrial volumes.

2. Technical Specifications & Physical Properties

5-Nitro-2-aminophenol exhibits a well-defined set of physical and chemical properties that ensure consistent and predictable performance in synthesis and formulation processes. The compound has a density of approximately 1.511 g/cm³, a boiling point of 364°C, and a flash point of 173.9°C. Its molecular structure features both amino (-NH₂) and nitro (-NO₂) substituents on a phenolic ring, providing reactive sites for diazotization, coupling reactions, and other synthetic transformations. The compound is stable under normal temperatures and pressures but should be stored long-term in a cool, dry place away from strong oxidizing agents, as it is a reducing agent that reacts slowly with oxygen in the air at room temperature. For industrial applications, typical purity specifications range from 90% (technical grade) to 95% or higher (high-purity grade), with each batch subject to quality assurance testing to verify purity and consistency.

3. Core Applications & Industrial Uses

5-Nitro-2-aminophenol is an essential intermediate in the production of azo dyes, which are widely used across the textile, leather, and paper industries. It is employed in the manufacture of metal complex dyes, reactive black dyes, neutral pink BL, and leather spray red GL. Beyond conventional dye applications, 5-NAP serves as a semipermanent (nonoxidative) hair colorant and as a toner in permanent (oxidative) hair dye products. The compound also functions as a starting material for the synthesis of biologically and pharmacologically active molecules, including potential anticonvulsant agents. In research settings, 5-NAP has been extensively studied for its analytical properties and is used as a reagent in chromatography. Additionally, it can be utilized in the manufacture of pesticides, rubber additives, and other organic compounds. The compound also serves as a precursor for synthesizing poly(5-nitro-2-aminophenol) via oxidative polymerization. With the textile industry projected to exceed $1 trillion by 2025, the demand for high-performance dye intermediates like 5-NAP continues to grow substantially. Its versatility across multiple application domains—from industrial colorants to pharmaceutical research—makes 5-NAP a valuable and dependable chemical intermediate for manufacturers and researchers worldwide.

4. Safety, Handling & Regulatory Information

5-Nitro-2-aminophenol is classified as a harmful substance (Xn) with hazard symbol and signal word Warning. Hazard statements include R36/37/38 (irritating to eyes, respiratory system, and skin) and R68 (possible risk of irreversible effects). The compound may cause skin irritation, serious eye irritation, and respiratory tract irritation upon exposure. Safety precautions require the use of appropriate personal protective equipment, including N95 dust masks, chemical safety goggles, and protective gloves. Handling should be conducted only in well-ventilated areas or outdoors, and skin contact must be avoided. The compound is listed as a Group 3 carcinogen by the World Health Organization’s International Agency for Research on Cancer (IARC), and animal studies have demonstrated that high concentrations may inhibit cell growth. Recommended safety phrases include S26 (in case of contact with eyes, rinse immediately with plenty of water and seek medical advice), S36/37/39 (wear suitable protective clothing, gloves, and eye/face protection), and S45 (in case of accident or if you feel unwell, seek medical advice immediately). The compound has a UN transport number of UN2811 and should be stored in a cool, dry, well-ventilated area, away from food materials and strong oxidizing agents. The use of 2-amino-5-nitrophenol in cosmetic products is prohibited in the European Economic Community. All products are intended for research and development or industrial use only and must be handled by technically qualified personnel.