Aminophenol

Updated: 2026-09-19

Overview

Aminophenol, chemically known as 4-aminophenol, is an aromatic organic compound featuring both amine and hydroxyl functional groups. It exists as white to light brown crystals and is a versatile intermediate in industrial chemistry. The compound is primarily synthesized by reducing nitrobenzene or hydrolyzing chlorobenzene derivatives. Its bifunctional nature allows it to participate in diverse chemical reactions, making it a key building block for pharmaceuticals, dyes, and specialty chemicals. Due to its reducing properties, it is also employed in photographic developers and as an antioxidant in rubber production.

Physical and Chemical Properties

Aminophenol exhibits moderate solubility in polar solvents like water and ethanol, with a melting point around 188-190°C. It decomposes upon heating beyond 284°C, releasing toxic fumes. The compound is sensitive to light and air, gradually darkening upon exposure. Chemically, it acts as a weak base and reducing agent. Its reactivity includes diazotization, acylation, and electrophilic substitution. The presence of both amine and hydroxyl groups enables its use in coupling reactions, forming azo dyes or pharmaceutical intermediates like paracetamol.

Main Applications

In the pharmaceutical industry, aminophenol is a precursor for paracetamol (acetaminophen), a widely used analgesic. It also serves in synthesizing other drugs, including antimalarials and anticonvulsants. The dye industry utilizes it to produce black and brown hair dyes, as well as azo pigments. Its reducing properties make it valuable in photographic developers, where it converts silver halides to metallic silver. Additionally, it acts as an antioxidant in rubber vulcanization and as a corrosion inhibitor in industrial processes.

Safety and Storage

Aminophenol is classified as harmful if ingested or inhaled and can cause skin and eye irritation. Proper personal protective equipment (PPE), including gloves and goggles, is mandatory during handling. Dust formation should be minimized to prevent respiratory exposure. Storage requires a cool, dry environment in tightly sealed containers, away from oxidizing agents and direct sunlight. Incompatible materials include strong acids, bases, and halogens. Spills should be contained with inert absorbents and disposed of as hazardous waste.

B2B Procurement Guide

Industrial buyers should prioritize suppliers that provide certificates of analysis (CoA) confirming purity (typically ≥98%) and CAS number verification. Packaging options include 25kg fiber drums or custom bulk quantities for large-scale users. Price varies based on purity and order volume, with bulk purchases often discounted. Logistics considerations include temperature-controlled transport for sensitive batches. Reliable suppliers are typically found in regions with strong chemical manufacturing infrastructure, such as China, India, and Europe.