NEWS
o-Aminophenol (C₆H₇NO) is an important aromatic organic compound with both amine (-NH₂) and hydroxyl (-OH) functional groups in the ortho position on a benzene ring. This white to light brown crystalline solid has a molecular weight of 109.13 g/mol and melts at 170-174°C. It exhibits moderate solubility in water (1.4 g/100 mL at 25°C) and better solubility in organic solvents like ethanol and ether.
Industrial production primarily involves:
Catalytic hydrogenation of o-nitrophenol using palladium or platinum catalysts
Reduction with iron in acidic medium
Electrochemical reduction methods
Key chemical properties include:
Weakly basic (pKa ~4.7 for NH₂ group)
Weakly acidic (pKa ~9.8 for OH group)
Susceptible to oxidation (forms dark-colored products)
Forms stable complexes with metal ions
Major industrial applications:
Dye industry: Precursor for azo dyes and hair colorants
Pharmaceuticals: Intermediate for antipyretic and analgesic drugs
Photography: Component in color developer solutions
Rubber industry: Antioxidant and antiozonant additive
Electroplating: Complexing agent in metal plating baths
Safety considerations:
Skin/eye irritant (GHS hazard statements H315, H319)
Potential environmental toxicity (aquatic hazard)
Requires proper PPE (gloves, goggles) during handling
Storage in cool, dry, well-ventilated areas
Recent research focuses on:
Novel synthetic routes with higher yields
Applications in coordination chemistry
Potential in advanced material synthesis
Biodegradation studies for environmental remediation
Environmental regulations increasingly control its production and disposal due to ecological concerns. Proper waste treatment methods include activated carbon adsorption and advanced oxidation processes.
The compound continues to be significant in specialty chemical manufacturing, with global demand estimated at 5,000-7,000 metric tons annually. Future developments may explore its potential in nanotechnology and biomedical applications.
