Aniline, with the chemical formula C6H5NH2 and CAS number 62-53-3, is a cornerstone of organic chemistry and a vital intermediate in numerous industrial processes. As the simplest aromatic amine, its unique chemical properties stem from the interplay between the phenyl group and the amino group.

The structure of aniline consists of a benzene ring attached to an amino (-NH2) group. This attachment significantly influences the reactivity of both the ring and the amino group. The lone pair of electrons on the nitrogen atom is partially delocalized into the pi system of the benzene ring. This resonance effect makes the amino group less basic than in aliphatic amines but activates the benzene ring towards electrophilic aromatic substitution, particularly at the ortho and para positions. This enhanced reactivity is a key factor in its utility for synthesizing various chemical compounds.

Industrially, aniline is primarily produced through the catalytic hydrogenation of nitrobenzene. This process involves reacting nitrobenzene with hydrogen gas at elevated temperatures and pressures in the presence of a metal catalyst, such as nickel, copper, or platinum. Historically, other methods like the Béchamp reduction using iron and acid were also employed.

The key chemical properties of aniline include its appearance: a colorless to slightly yellow liquid with a characteristic faint, fishy odor. It has a relatively high boiling point (around 184°C) and a melting point of -6.2°C. Aniline is sparingly soluble in water but readily soluble in organic solvents like ethanol and ether.

Aniline undergoes a wide array of reactions, reflecting its dual functionality. Oxidation reactions can lead to complex products, while electrophilic substitution on the ring is facile. Importantly, the amino group can be diazotized by reaction with nitrous acid to form diazonium salts, which are incredibly versatile intermediates for synthesizing dyes, pigments, and pharmaceuticals via reactions like the Sandmeyer reaction. Its ability to form amides (anilides) when reacted with carboxylic acids or their derivatives is also a critical transformation in organic synthesis.

When considering sourcing Aniline, understanding these aniline chemical properties is crucial. The purity of the Aniline, often specified as 99.9%, dictates its suitability for sensitive applications like pharmaceutical synthesis or high-performance dye manufacturing. Companies looking to buy aniline online should prioritize suppliers that can guarantee these specifications and provide detailed technical data sheets. The foundational chemistry of aniline continues to support innovation across multiple industrial sectors.