The diazonium group is N₂⁺. Arenediazonium ions formed by primary aromatic amines are stable for a short time in solution at low temperatures (273-278 K), and their stability is explained based on resonance.

Diazonium salts are named by suffixing “diazonium” to the name of the parent hydrocarbon, followed by the name of the anion (e.g., chloride, hydrogensulphate). The general formula for diazonium salts is R N₂⁺X⁻, where R represents an aryl group, and ...

Aniline does not undergo Friedel-Crafts reactions (alkylation and acetylation) due to salt formation with aluminum chloride, acting as a Lewis acid catalyst. The positive charge acquired by nitrogen in the aniline-AlCl₃ complex makes it a strong deactivating group for further ...

Aniline reacts with concentrated sulfuric acid to form anilinium hydrogensulphate, which, upon heating, produces p-aminobenzene sulphonic acid (sulphanilic acid) as the major product at 453-473K.

Direct nitration of aniline yields tarry oxidation products alongside nitro derivatives. In strongly acidic conditions, aniline forms the anilinium ion, which is meta-directing. Acetylation of the -NH₂ group can control nitration, favoring the formation of the p-nitro derivative as the ...

Acetylation with acetic anhydride protects the -NH₂ group in aniline during electrophilic substitution, and the resulting -NHCOCH₂ group has a less activating effect due to resonance interactions that make the lone pair on nitrogen less available for donation to the ...

Aromatic amines, like aniline, exhibit very high reactivity in electrophilic substitution, favoring ortho- and para-positions. To control the activating effect of the -NH₂ group for monosubstitution, acetylation with acetic anhydride can be performed, followed by desired substitution and hydrolysis of ...

The -NH₂ group in aniline is ortho- and para-directing, making these positions centers of high electron density in its resonance hybrid structures.

Tertiary amines do not react with benzenesulphonyl chloride, providing a basis for distinguishing between primary, secondary, and tertiary amines. This property is employed for the separation of amine mixtures. Nowadays, p-toluenesulphonyl chloride is commonly used in place of benzenesulphonyl chloride.

The reaction of benzenesulphonyl chloride with secondary amines yields N,N-diethylbenzenesulphonamide, which lacks acidic hydrogen and is insoluble in alkali due to the absence of a hydrogen atom attached to the nitrogen.