Benzenamine · Phenylamine · Aminobenzene · Aniline oil · Technical and distilled grades
Aniline is the simplest aromatic amine — a benzene ring carrying one primary amino group — and the parent molecule of the entire aromatic amine industry. Because the nitrogen lone pair is drawn into the ring, aniline is a far weaker base than an aliphatic amine, but a far better nucleophile at the ring: it diazotises, it condenses, it alkylates and it substitutes at the ortho and para positions with ease. That reactivity makes it the feedstock for MDI and polyurethanes, rubber processing chemicals, azo dyes, agrochemicals and pharmaceutical intermediates. Chelora Amines supplies aniline in technical and distilled grades, with a batch-wise COA and SDS on every dispatch.
72.06 + 7.06 + 14.01 = 93.13 g/mol
Aniline, also called benzenamine, phenylamine or aminobenzene, is a primary aromatic amine consisting of a benzene ring with one –NH₂ group. It is a colourless to pale yellow oily liquid when fresh, with a characteristic amine odour, and it darkens steadily to yellow, amber and finally reddish-brown as it oxidises in air and light. That darkening is cosmetic rather than chemical ruin — but low-colour material is a requirement in dye and pharmaceutical work, which is why distilled grades are supplied under nitrogen.
Aniline is only weakly basic. The nitrogen lone pair is delocalised into the aromatic ring, so the conjugate acid has a pKa of about 4.6, against roughly 10.6 for a typical aliphatic amine. The flip side of that delocalisation is a strongly activated ring: aniline undergoes electrophilic substitution far more readily than benzene, and almost exclusively at the ortho and para positions.
Commercially, aniline is overwhelmingly an intermediate rather than an end product. The great majority of world output is condensed with formaldehyde and converted to MDI for polyurethanes; the remainder splits between rubber processing chemicals, dyes and pigments, agrochemicals, pharmaceutical intermediates and speciality polymers.
| Chemical name | Aniline (benzenamine) |
| Common synonyms | ANL, phenylamine, aminobenzene, benzenamine, aniline oil |
| CAS number | 62-53-3 |
| EC / EINECS number | 200-539-3 |
| HS / HSN code | 2921 41 (aniline and its salts; HSN 2921 41 on Indian invoices) |
| Molecular formula | C₆H₇N (C₆H₅NH₂) |
| Molecular weight | 93.13 g/mol |
| Appearance | Colourless to pale yellow oily liquid; darkens to brown in air and light |
| Odour | Characteristic amine-like, faintly aromatic |
| Melting / freezing point | About −6 °C |
| Boiling point | About 184 °C at atmospheric pressure |
| Density | About 1.021–1.023 g/cm³ at 20 °C |
| Viscosity | About 3.8 cP at 25 °C |
| Refractive index | About 1.586 at 20 °C |
| Solubility in water | About 36 g/L at 20 °C; miscible with alcohol, ether, benzene and most organic solvents |
| Basicity | pKa of the conjugate acid about 4.6 — a weak base |
| Flash point | About 70 °C (closed cup) — combustible liquid |
| Autoignition temperature | About 615 °C |
| UN number | UN 1547, Aniline, Class 6.1, Packing Group II |
Figures are typical values for the technical grade. Distilled and laboratory grade values may differ. All values for the material you order are stated on its Certificate of Analysis and Safety Data Sheet.
Two reactive sites, one molecule: the amino nitrogen reacts as a nucleophile and a weak base, while the ring it is attached to is activated towards electrophiles at the ortho and para positions. Nearly every aniline derivative in commerce comes from one of the routes below.
Acid-catalysed condensation of two aniline molecules with formaldehyde gives methylenedianiline, the direct precursor to MDI and polymeric MDI — by volume, the largest single use of aniline.
2 C₆H₅NH₂ + HCHO → MDA + H₂OTreatment with nitrous acid at low temperature gives the benzenediazonium salt, which couples with phenols and amines to give azo dyes and pigments — the foundation of synthetic colour chemistry.
ArNH₂ + HNO₂ + HCl → ArN₂⁺Cl⁻Two aniline molecules condense over an acidic catalyst with loss of ammonia to give diphenylamine, the backbone of rubber and lubricant antioxidants.
2 C₆H₅NH₂ → (C₆H₅)₂NH + NH₃Reaction with acetic anhydride or acid chlorides gives acetanilide and other anilides — pharmaceutical intermediates, and a standard way to protect the amino group before ring substitution.
ArNH₂ + (CH₃CO)₂O → ArNHCOCH₃Methylation or ethylation gives N-methylaniline, N,N-dimethylaniline and N,N-diethylaniline — used in dyes, polymerisation accelerators and as organic bases.
ArNH₂ + 2 CH₃OH → ArN(CH₃)₂ + 2 H₂OThe –NH₂ group is a powerful activator and an ortho/para director. Halogenation, sulfonation and controlled nitration give the chloroanilines, sulfanilic acid and nitroanilines used in dyes and agrochemicals.
ortho / para selectiveAniline reacted with carbon disulfide and sulfur gives mercaptobenzothiazole and the thiazole family of rubber vulcanisation accelerators.
ArNH₂ + CS₂ + S → MBT + H₂SAs a weak base, aniline needs a strong acid to form a stable salt. Aniline hydrochloride and aniline sulfate are water-soluble and are used directly in dye, pigment and leather processing.
ArNH₂ + HCl → ArNH₃⁺Cl⁻Process notes. Aniline oxidises slowly in air and light, darkening through yellow to brown and eventually depositing resinous colour bodies. Store under nitrogen, out of direct light, and keep drums sealed. It is readily absorbed through intact skin and causes methaemoglobinaemia — closed transfer and full PPE are not optional. Avoid copper, copper alloys and brass. Aniline reacts violently with strong oxidising agents, including nitric acid and peroxides; keep these strictly segregated.
Discuss your processNearly all commercial aniline is made by the nitrobenzene route: benzene is nitrated, then the nitro group is hydrogenated to a primary amine. A minority of world capacity runs on the phenol ammonolysis route where phenol is the cheaper feedstock.
Petrochemical benzene of refined purity is taken as the aromatic backbone, with specification controls on sulfur and non-aromatics.
Benzene is converted to nitrobenzene in a continuous process, with the spent acid separated, reconcentrated and recycled.
Nitrobenzene is hydrogenated over a supported metal catalyst, converting the nitro group to a primary amine and releasing water as the only by-product.
The crude is dehydrated and fractionally distilled to remove water, residual nitrobenzene, cyclohexylamine and heavy ends, giving aniline of 99.5% and above.
Purity, colour, moisture and residual nitrobenzene are tested, then the material is filled and blanketed with nitrogen to hold its colour.
Technical-grade aniline at 99.5% and above — still widely called aniline oil — is the standard feed for MDI, rubber chemicals and bulk intermediate synthesis, where a slightly higher initial colour and a trace of residual nitrobenzene make no practical difference. Distilled grade is redistilled to a tighter purity and a much lower APHA colour, with residual nitrobenzene held well below the technical limit, and is specified for dye, pigment, pharmaceutical and fine-chemical work where colour carries through to the final product. If low colour matters to you, say so at enquiry stage, and specify both the APHA limit and the maximum acceptable storage time between manufacture and use.
Freshly distilled aniline is water-white. Exposure to air and light starts an oxidation chain that produces first a yellow tint, then amber, then reddish-brown, with colour bodies eventually settling out as a resinous deposit. Nothing reverses this, so the whole handling strategy is preventive: nitrogen blanket on drums and tanks, dark storage, minimum headspace, and prompt use after opening. In sealed, nitrogen-blanketed containers stored cool and dark, aniline normally holds specification for twelve months from manufacture. For colour-critical work we recommend ordering against your draw-down rate rather than holding stock.
The right grade depends on how much colour and residual nitrobenzene matter downstream. Technical grade covers bulk intermediate synthesis; distilled grade is for colour-critical and pharmaceutical work.
Aniline oil for MDI, rubber chemicals, agrochemicals and general intermediate synthesis.
Redistilled, low-colour material with tight residual nitrobenzene limits for dyes, pigments and pharmaceutical intermediates.
Highest purity for analytical, research and calibration use. Packed in sealed amber bottles under nitrogen.
| Parameter | Test method | Typical specification |
|---|---|---|
| Appearance | Visual | Clear colourless to pale yellow oily liquid |
| Purity (aniline) | GC | ≥ 99.5% w/w |
| Colour (APHA) at dispatch | APHA / Hazen | ≤ 50 |
| Nitrobenzene | GC | ≤ 500 ppm |
| Cyclohexylamine | GC | ≤ 500 ppm |
| Water | Karl Fischer | ≤ 0.3% w/w |
| Freezing point | Crystallising point | ≥ −6.5 °C |
| Density at 20 °C | Densitometer | 1.021 – 1.024 g/cm³ |
| Residue on evaporation | Gravimetric | ≤ 0.05% w/w |
Indicative specification for planning. The controlling document is the Certificate of Analysis issued for your batch. If your process needs a tighter colour or nitrobenzene limit, say so at enquiry stage.
Aniline is a building block rather than a finished product — it rarely appears in the article a consumer buys, but it is upstream of an enormous amount of it.
The largest single outlet. Aniline is condensed with formaldehyde to MDA, then converted to MDI and polymeric MDI for rigid insulation foam, flexible foam, binders and adhesives.
Feedstock for vulcanisation accelerators such as MBT and MBTS, and — through diphenylamine and 4-ADPA — for the antiozonants that keep tyre sidewalls from cracking.
Diazotised and coupled to give azo dyes and organic pigments for textiles, inks, plastics and paper; also the route into indigo and sulphur dye chemistry.
Ring-substituted anilines are intermediates for acetanilide and phenylurea herbicides, carbamate and phenylamide fungicides and several insecticide families.
Upstream of paracetamol through p-aminophenol, of the sulfonamide family through sulfanilic acid and sulfanilamide, and of a long list of acetanilide-based actives.
Aromatic diamines derived from aniline go into polyimides, polyamide-imides, aramid fibres and engineering resins where thermal stability is the requirement.
Aniline-derived imidazolines, Schiff bases and quaternaries are used in acidising inhibitors, pickling inhibitors and oilfield chemical packages.
A standard reagent and reference material in organic synthesis teaching, derivatisation chemistry and the preparation of aniline-based stains and indicators.
From insulation foam to tyre sidewalls to textile dye — the value chain downstream of ANL.
| Derivative | Made by | End use |
|---|---|---|
| 4,4′-Methylenedianiline (MDA) | Acid-catalysed condensation with formaldehyde | MDI and polymeric MDI, epoxy curing agents, polyimides |
| Diphenylamine (DPA) | Thermal condensation of two aniline molecules | Rubber and lubricant antioxidants, propellant stabiliser |
| Mercaptobenzothiazole (MBT) | Reaction with carbon disulfide and sulfur | Rubber vulcanisation accelerators |
| Azo dyes and pigments | Diazotisation and coupling | Textile dyes, printing inks, plastics and paper colours |
| N,N-Dimethylaniline | N-methylation | Dye intermediates, polymerisation accelerators, organic base |
| Acetanilide | Acetylation with acetic anhydride | Pharmaceutical intermediate, peroxide stabiliser |
| Sulfanilic acid and sulfanilamide | Sulfonation and rearrangement | Azo dyes, sulfonamide pharmaceutical actives |
| Aniline hydrochloride / sulfate | Neutralisation with mineral acid | Dye, pigment and leather processing |
Every container carries the Chelora Amines label with product name, grade, net weight, batch number, manufacturing date, UN number and hazard pictograms. All packs are nitrogen-purged before sealing.
UN-approved mild steel or lined steel drums for production use. Nitrogen-purged and sealed; re-blanket the drum after every draw to protect colour.
For high-volume users. Earthing points fitted, nitrogen blanket on delivery, suitable for closed pump transfer into your day tank.
ISO tanks and road tankers for continuous consumers; 500 mL to 5 L amber bottles under nitrogen for laboratory and pilot work.
Because aniline darkens on contact with air, tell us your anticipated draw-down rate, storage temperature and colour requirement at enquiry stage — we will recommend the pack size and nitrogen-blanketing arrangement that protects the material between uses. Export consignments are packed in UN-specification containers and shipped FOB, CIF or CFR through Nhava Sheva and Mundra.
Plan my supplyAniline is toxic if swallowed, inhaled or absorbed through the skin, and skin absorption is the route most often underestimated. It converts haemoglobin to methaemoglobin, reducing the blood's ability to carry oxygen; it is classified as a suspected carcinogen and as causing damage to blood and spleen through repeated exposure. The notes below are a summary for planning only — always work to the Safety Data Sheet supplied with your consignment, your own site risk assessment and your local occupational exposure limits.
| Parameter | Specification | Result |
|---|---|---|
| Appearance | Clear colourless to pale yellow | Complies |
| Purity (GC) | ≥ 99.5% | Complies |
| Colour (APHA) | ≤ 50 | Complies |
| Nitrobenzene | ≤ 500 ppm | Complies |
| Water (KF) | ≤ 0.3% | Complies |
| Residue on evaporation | ≤ 0.05% | Complies |
Aniline is checked before dispatch. Each consignment leaves with the paperwork your QC, stores and accounts teams need on day one — including the colour and residual nitrobenzene figures that matter downstream.
Five steps for a first order of aniline.
Grade, quantity, pack size, colour limit if colour is critical, and your delivery location or destination port.
We confirm grade and pack for your application and quote, usually within 24 hours.
The batch is tested — purity, colour, moisture and nitrobenzene — and the COA, SDS and invoice details are prepared.
Nitrogen-purged and sealed packs move by road under dangerous goods documentation, or in export packing for overseas buyers.
Material reaches your gate and repeat dispatches are scheduled to your usage, keeping storage time short to protect colour.
Buyers who order aniline usually source these from the same list. See the full product range for the complete picture.
Short answers to what purchase, lab and plant teams ask us most. Anything else, ask us directly.
Send the grade, quantity, pack size and your delivery address or destination port. We come back with a price, the documents that go with the batch and a dispatch or shipping plan, usually within 24 hours.