4-Bromophenol

Updated: 2026-08-07

Overview

4-Bromophenol is an aromatic organic compound featuring a hydroxyl group and a bromine atom attached to a benzene ring in the para position. It is a versatile intermediate in organic synthesis, particularly in the production of pharmaceuticals, agrochemicals, and specialty chemicals. The compound is typically synthesized through the bromination of phenol or via diazotization reactions. As a brominated derivative of phenol, 4-bromophenol exhibits both the reactivity of phenols (e.g., acidity, electrophilic substitution) and the properties imparted by the bromine substituent. Its moderate reactivity makes it valuable for further functionalization in synthetic chemistry.

Physical and Chemical Properties

4-Bromophenol presents as white to pale yellow crystals with a characteristic phenolic odor. It has a relatively high density (1.84 g/cm³) due to the presence of the heavy bromine atom. The compound melts at 64-66°C and boils at 238°C, with moderate volatility under standard conditions. Chemically, it behaves as a weak acid (pKa ~9.3) and undergoes typical phenol reactions such as etherification and esterification. The bromine atom activates the aromatic ring for electrophilic substitution at the ortho and para positions. It is soluble in most organic solvents but only slightly soluble in water (approximately 0.5 g/L at 20°C).

Main Applications

In the pharmaceutical industry, 4-bromophenol serves as a key intermediate for synthesizing various active pharmaceutical ingredients (APIs), particularly those containing brominated aromatic structures. It's used in the production of analgesics, antiseptics, and other specialty drugs. The agrochemical sector utilizes this compound in manufacturing herbicides, fungicides, and pesticides. Its bromine content contributes to the biological activity of these products. Additionally, it finds use in dye synthesis, where it helps create brominated dye intermediates, and as a precursor for flame retardants in polymer applications.

Safety and Storage

4-Bromophenol requires careful handling due to its irritant properties. It can cause skin and eye irritation upon contact and is harmful if swallowed or inhaled. Appropriate personal protective equipment (PPE) including gloves, goggles, and respiratory protection should be used when handling the chemical. For storage, keep containers tightly closed in a cool, dry, well-ventilated area away from strong oxidizers. The compound is relatively stable under normal conditions but may decompose upon heating, releasing toxic fumes including hydrogen bromide. Shelf life is typically 2-3 years when stored properly in original packaging.

B2B Procurement Guide

When sourcing 4-bromophenol for industrial use, prioritize suppliers who provide detailed certificates of analysis (CoA) specifying purity (typically ≥98%), moisture content, and impurity profiles. Bulk quantities (25kg drums or larger) usually offer better pricing, with prices commonly ranging between $50-$100/kg depending on order volume and purity requirements. Key procurement considerations include verifying the supplier's quality management certifications (e.g., ISO 9001), transportation compliance (especially for international shipments), and packaging integrity. Technical-grade material is sufficient for most industrial applications, while pharmaceutical-grade commands a premium price. Establish long-term supply agreements to mitigate price fluctuations.