Aniline

Aniline is the simplest aromatic amine: a single amino group on an unsubstituted benzene ring, with none of the chlorine, fluorine, methyl or nitro substituents that define every other product in our range. It is also the starting point for most of them — directly or indirectly, the great majority of the aniline derivatives we supply are made by substituting this molecule, not by building an aromatic amine from scratch each time.

It is a colourless oily liquid when fresh, darkening to brown, red or yellow on exposure to air and light — the same behaviour seen throughout the aniline family, here in its most pronounced form, since the unsubstituted ring offers no steric protection against oxidative degradation. It is appreciably soluble in water at 3.4–3.6 g/100 mL, more so than any substituted aniline in our range, and its log P of 0.90 confirms it as the least lipophilic member of the family.

Where it fits in the synthesis chain

The scale of aniline's industrial use dwarfs every other product on this site. Production of 4,4′-methylenediphenyl diisocyanate, MDI, for polyurethane foams, elastomers and coatings accounts for more than 90% of global aniline consumption — by a wide margin the dominant outlet. The remaining volume is split across rubber-industry antidegradants and accelerators, dye and pigment manufacture, and smaller pharmaceutical and herbicide intermediate uses. Aniline's historical role as the dye industry's founding raw material — the 1856 discovery of mauveine from impure aniline is often cited as the birth of the synthetic dye industry — has been dwarfed by the modern polyurethane chain, though dye-sector demand continues.

Grades we supply

Chelora Chemicals offers Aniline in technical grade (99.5%) for standard industrial synthesis and high-purity grade (99.9%+) for MDI and pharmaceutical-adjacent manufacture where trace impurities carry forward into sensitive processes. Both ship with a batch-wise certificate of analysis. Given the scale at which this product moves, bulk and ISO-tank logistics are available alongside standard drums — tell our desk your required volume and we will quote the appropriate mode.

Aniline is made almost exclusively by the catalytic hydrogenation of nitrobenzene, run at elevated temperature over a metal catalyst — nickel, copper, palladium or platinum, depending on the plant — with nitrobenzene itself produced by nitrating benzene. This two-step sequence, benzene to nitrobenzene to aniline, is the foundation route for the entire aniline-derivative industry: every substituted aniline we supply traces back to this chemistry at some point in its history, whether the substitution happens before or after the nitro-reduction step.

A minor alternative route reacts phenol with ammonia under catalysis, typically using phenol from the cumene process. It remains a smaller contributor to global supply than the nitrobenzene route.

After reduction the crude aniline is purified by distillation to remove unreacted nitrobenzene, partially reduced intermediates and catalyst residues. Technical and high-purity grades diverge at this distillation cut, with the high-purity stream taken more tightly for applications — MDI manufacture prominent among them — that are sensitive to trace impurity carryover.

The foundation reaction for this entire product category

Nearly every other product on this site is aniline with something attached — a chlorine, a fluorine, a methyl group, a nitro group, an alkyl chain. Understanding how aniline itself is made is therefore the starting point for understanding how the whole family is made: substituents are installed either before the nitro-reduction step (nitrating a pre-substituted benzene, then reducing) or after it (reacting aniline itself, as with the 2,6-dialkylanilines in our range, which are made by alkylating aniline directly rather than reducing a nitro precursor).