Para Nitroaniline
Para Nitroaniline — PNA or 4-nitroaniline — is the parent diazo component behind Para Red, the first azo dye ever synthesised, and remains one of the highest-volume aniline intermediates in the colourant industry today. It also feeds rubber antioxidant, corrosion-inhibitor and fuel-additive chemistry through its reduction product, para-phenylenediamine.
Chelora Chemicals supplies PNA to pigment houses, dye manufacturers and fine chemical producers worldwide, in bags, drums and container quantities, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 100-01-6
- IUPAC name
- 4-Nitroaniline
- Molecular formula
- C6H6N2O2
- Molecular weight
- 138.12 g/mol
- EC / EINECS
- 202-810-1
- SMILES
- Nc1ccc(cc1)[N+](=O)[O-]
- HS Code
- 2921 42*
* Confirm the exact HS heading with your customs broker — classification of substituted aniline derivatives varies between destination tariffs.
What Para Nitroaniline is used for
Para Nitroaniline is an aniline carrying a nitro group para to the amino group. The nitro substituent is strongly electron-withdrawing, which deactivates the ring, sharply lowers the basicity of the amine, and — once diazotised — gives a diazonium salt that couples cleanly onto naphthols and acetoacetarylides to build a deep, fast, well-defined chromophore. That single reaction, run for the first time in the 1880s, produced Para Red, the first azo dye ever made, and PNA has anchored azo colourant chemistry ever since.
In practice PNA is a captive intermediate: plants buy it to diazotise for pigments and dyes, or to reduce to para-phenylenediamine (p-PDA) for rubber antioxidant, hair-dye and specialty polymer chemistry. Very little of it is ever sold on as-is.
Why the isomer matters
The three nitroaniline isomers behave very differently in the plant, and a mis-substitution downstream is not recoverable:
- 4-Nitroaniline (CAS 100-01-6) — this product. Nitro para to the amine. The highest-volume of the three and the workhorse of azo dye chemistry.
- 2-Nitroaniline (CAS 88-74-4) — the ortho isomer, a lower-melting solid used mainly as a precursor to benzimidazolone pigments and 2-nitrochloro/fluorobenzene downstream chemistry.
- 3-Nitroaniline (CAS 99-09-2) — the meta isomer, made by a different route (nitro-reduction of 1,3-dinitrobenzene) and used across a narrower dye and pharma chemistry.
If your purchase order simply says "nitroaniline", quote us the CAS number and we will confirm the correct material before the order is placed. Related aniline intermediates — chloroanilines, toluidines and anisidines — are available across our full product range.
Appearance and handling character
PNA ships as a bright yellow to golden crystalline solid or powder melting around 147 °C — comfortably solid through most transport and storage conditions. It is sparingly soluble in water and dissolves in alcohols, acetone and hot aromatic solvents. As with other aromatic amines, it can drift slightly in shade with prolonged exposure to strong light. Read the safety section before planning any handling programme: this material is an acute toxicant by all three exposure routes, and the powder form makes dust control a first-order concern.
| Parameter | Typical value |
|---|---|
| Appearance | Yellow crystalline powder / flakes |
| Assay (HPLC/GC) | 99.0% min |
| Moisture (KF) | 0.3% max |
| Melting range | 145 – 149 °C |
| Isomeric & related impurities | 1.0% max |
| Heavy metals | Reported per batch |
Important: the figures above are indicative of commercial grade material and are offered for planning only. The batch certificate of analysis is the governing document. If your process demands a tighter assay, a colour ceiling or a controlled moisture figure, send us the specification and we will quote against it rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Crystalline solid at ambient |
| Melting point | ≈ 147 °C |
| Boiling point | ≈ 332 °C @ 760 mmHg |
| Flash point | ≈ 199 – 213 °C |
| Relative density | ≈ 1.44 |
| Partition coeff. (log P) | ≈ 1.39 |
| Water solubility | Sparingly soluble (≈ 0.8 g/L, 20 °C) |
| Organic solubility | Soluble in hot alcohols, acetone & aromatic solvents |
| Odour | Faint, amine-like |
Physical constants compiled from public reference data for CAS 100-01-6 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
PNA's volume sits overwhelmingly in colour chemistry, with meaningful secondary demand from rubber, corrosion-inhibitor and fine chemical manufacturers.
Azo dyes & pigments
The defining outlet. Diazotised PNA couples onto naphthol AS and acetoacetarylide components to build red, orange and yellow azo pigments and dyes — the same chemistry that produced Para Red, the very first azo dye.
- Diazo component in azo pigment synthesis
- Shade and fastness depend directly on purity
- See our full aniline intermediate range
Rubber antioxidants
Reduction of PNA gives para-phenylenediamine (p-PDA), the aromatic core of the p-phenylenediamine-class antiozonants and antioxidants that protect tyre and rubber goods compounds from ozone cracking.
- p-PDA precursor chemistry
- Tyre and technical rubber goods sector
- Tight isomer limits usually apply
Corrosion inhibitors & fuel additives
PNA and its derivatives are used as building blocks for antioxidant and corrosion inhibitor packages in fuels and lubricants, and as gum inhibitors in stored motor gasoline.
- Antioxidant package chemistry
- Fuel stability and gum inhibition
- See our agrochemical intermediate range
Pharmaceutical & agro intermediates
The 4-nitrophenyl-amine fragment appears across several established synthetic routes in pharma and crop-protection chemistry — through amide formation, ring construction and further nitro-group chemistry.
- Amide, urea and sulfonamide formation
- Heterocyclic ring construction
- See also para fluoroaniline
Fine & specialty synthesis
A well-characterised aryl amine building block for custom amides, azo dyes, Schiff bases and ligand work where the 4-nitrophenyl group is required and the nitro group may itself be reduced later in the sequence.
- Custom amide and azo dye formation
- Nitro group retained for later reduction
- Available in trial and laboratory quantities
Contract & scheduled supply
Pigment plants run to campaign, not to a calendar month. Most PNA buyers want tonnage released against a production plan rather than in one shipment. We hold inventory and release it to your schedule.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Para Nitroaniline
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no nitroaniline plant — and for a specification-sensitive intermediate like this one, that independence works in your favour. We are never obliged to push you whatever a captive unit happens to be running that month.
Instead we place your order with whichever qualified producer best matches your assay, your colour requirement, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, or logistics are disrupted, your campaign switches source rather than stalling.
- Specification read against the CAS first. We confirm you need 100-01-6 and not the ortho or meta isomer before we quote a price.
- Batch COA shared before dispatch. You approve the assay, moisture and colour profile against your own spec while the material is still in our warehouse.
- Hazard status stated up front. This material is toxic by ingestion, skin contact and inhalation, and we say so at enquiry stage — not in the small print of a document pack that arrives with the goods.
- Pre-shipment samples for qualification. New account or new source, your R&D team runs a lab batch before the full quantity ever moves.
- Packing chosen to control dust. A fine yellow powder generates airborne dust readily. We plan pack format and liner choice with exposure in mind.
- Export machinery handled in-house. Hazard classification, UN-approved packing, labelling, freight booking and customs paperwork are ours to manage.
- Consolidation onto one bill of lading. Ship PNA alongside other intermediates from our range — one invoice, one shipment, one counterparty.
Packed the way your plant receives it
Pack format drives your landed cost, your handling effort, and — for a fine toxic powder — your operator exposure. Tell us how it will be charged at your end and we will quote the format that suits your operation.
Multi-wall paper & PE bags
Laminated multi-wall bags with an inner liner, palletised and shrink-wrapped. The default for LCL movements and for plants charging batch-wise by hand.
Fibre & HDPE drums
UN-certified drums with liner for longer sea transits and humid destinations. Better protection against moisture pick-up and caking than bagged material.
Jumbo / FIBC bags
Bulk bags with liner for high-volume users with closed mechanical charging. Fewer handling movements and materially lower packing cost per kilo.
Samples & trial packs
Laboratory samples and pilot quantities dispatched by courier so your R&D team can qualify the grade before committing to campaign volume.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to. Ocean, air and road freight arranged end-to-end with documentation filed before booking.
Campaign despatch
Pigment production runs to campaign. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Handle this as a classified acute toxicant
This is the point on the page that matters most. Para nitroaniline is toxic by ingestion, skin contact and inhalation, carries a specific target organ toxicity entry, and is very toxic to aquatic organisms. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document and should govern your risk assessment, PPE selection, exposure monitoring and emergency planning.
Classified hazards
H301Toxic if swallowed.H311Toxic in contact with skin.H331Toxic if inhaled.H373May cause damage to organs (blood) through prolonged or repeated exposure.H412Harmful to aquatic life with long lasting effects.
Hazard statements reflect the harmonised GHS classification commonly published for CAS 100-01-6 (GHS06 Toxic, GHS08 Health hazard). Supplier classifications may differ in detail; always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the pallet arrives, not after a bag splits. The points below are orientation for your emergency planners — sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Sweep, do not hose. The material is harmful to aquatic life. Collect spilled solid mechanically into a labelled container; never wash it to a drain.
- Suppress dust. Dry sweeping of a fine yellow powder generates an inhalable aerosol — use vacuum collection or dampen carefully in line with the SDS.
- Assume skin absorption. Contaminated clothing is a continuing exposure route — remove it immediately and wash the skin thoroughly.
- Have the SDS with the casualty. Nitroanilines can cause methaemoglobinaemia, and the treating clinician needs the product identity and CAS number in hand.
- Monitor blood parameters after significant exposure. H373 flags a specific target organ (blood) risk on repeated exposure — that is a decision for your occupational health provider to build into a surveillance programme.
Storage
- Cool, dry, well-ventilated store, away from direct sunlight and heat sources. The melting point is around 147 °C, so ordinary tropical transport temperatures are not a concern for caking.
- Keep containers tightly closed. Moisture pick-up and prolonged light exposure can affect colour over long storage.
- Segregate from oxidising agents, strong acids and reducing agents. Nitroanilines can react vigorously with strong reducing agents and oxidisers.
- Access-controlled store. Restricting who can reach an acute toxicant is part of the control, not an administrative nicety.
- Shelf life is typically 12–24 months in sealed original packing under these conditions. Re-assay before use after long storage.
Handling & PPE
- Design exposure out. Closed transfer and mechanical charging first, local exhaust ventilation second, PPE last — the standard hierarchy of control for a fine toxic powder.
- Skin protection is the priority. Nitroanilines are absorbed through intact skin — use chemical-resistant gloves and coveralls, not just splash protection.
- Respiratory protection where dust may be generated — particularly when charging reactors or emptying a bulk bag — per your own exposure assessment.
- Health surveillance where indicated. The H373 (blood) entry means some sites build periodic monitoring into their occupational health programme for regular handlers.
- Never discharge to drain or watercourse. H412 applies — collect spills as solid waste and dispose of them as regulated chemical waste.
Transport
PNA moves as regulated cargo. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made. The applicable UN number, class and packing group are stated on your shipping documents and SDS — ask us for the current DG paperwork when you plan the shipment.
What travels with every consignment
A chemical shipment is only as good as the file that travels with it. Verifying what the source plant sends is precisely the work you are buying from a supplier.
Certificate of Analysis
Batch-specific assay by HPLC/GC, moisture by Karl Fischer, appearance, melting range and impurity profile — checked against your purchase specification before we release the goods.
GHS Safety Data Sheet
Full 16-section SDS in GHS format covering hazards, exposure controls, handling, storage, spill response, toxicology and disposal — issued in the language your destination requires.
Dangerous Goods Declaration
UN number, hazard class, packing group and IMDG or IATA declaration prepared and filed before the container is booked, with correctly marked and labelled packaging.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief at the destination.
Third-party inspection
SGS, Intertek or Bureau Veritas sampling and inspection arranged on request before loading, giving you independent verification of what actually ships.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives. Retention samples held against the batch.
The two doors out of this aniline
Almost everything made from PNA leaves by one of two routes: the diazonium salt, or reduction of the nitro group. Understanding which one you are using explains why the specification matters and which impurity will hurt you. The routes below are the general industrial pattern, not a process disclosure.
Start with the aniline
PNA provides a primary aromatic amine with a strongly electron-withdrawing nitro group locked at the para position, which shapes both the diazotisation and the reduction chemistry built on it.
Door one — diazotise
Sodium nitrite in acid at low temperature gives the diazonium salt, which is coupled onto a naphthol or acetoacetarylide to build an azo pigment or dye — the Para Red reaction.
Door two — reduce the nitro group
Catalytic or chemical reduction converts the nitro group to a second amine, giving para-phenylenediamine — the entry point to rubber antioxidant and specialty polymer chemistry.
Finish to grade
The crude product is crystallised, washed and dried, then standardised or purified to whatever the end market demands — colour target or a controlled impurity limit.
Why feed quality carries through the whole route
Both doors act on a functional group attached to the same ring. Anything in the feed that competes for that chemistry, or carries its own reactive functionality, follows the material down the line:
- Isomeric nitroanilines diazotise or reduce in parallel and give structurally similar products — an off-shade chromophore in colour work, an unwanted isomer in p-PDA production.
- Residual moisture can complicate both diazotisation control and clean catalytic reduction, affecting yield and batch consistency.
- Coloured degradation products dull a finished shade and can show as off-colour in an otherwise bright yellow solid.
- Heavy metal residues from reduction catalysts, if carried through the supply chain, concentrate in downstream product and can trip pharma or food-contact specifications.
That chain of consequences is the reason we quote against your written specification rather than a generic "99% technical" grade, and the reason the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Intermediate | Principal outlet |
|---|---|
| Para Nitroaniline CAS 100-01-6 — this product | Azo dyes & pigments (Para Red) p-Phenylenediamine Corrosion inhibitors |
| Ortho Nitroaniline CAS 88-74-4 | Benzimidazolone pigments Dye intermediates |
| Ortho Toluidine CAS 95-53-4 | Rubber chemicals Agrochemical intermediates |
If your route calls for a different isomer or a related intermediate, we supply those as well — see our full product catalogue. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
PNA is not a commodity with a screen price. Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Pigment demand cycles
Textile, coatings, printing-ink and plastics colourant demand pull on the same aniline through the year, so the market rarely goes quiet in the way a niche single-outlet intermediate does.
- Quote early for campaign tonnage
- Spot buying at peak costs materially more
- Contracted call-off smooths the exposure
Upstream feedstock
The route back to PNA runs through nitrobenzene, nitration and selective reduction. Movements in benzene, nitric acid and ammonia feed through to the aniline within a quarter or so.
- Benzene and nitric acid set the floor
- Energy cost weighs on the nitration/reduction steps
- We flag feedstock-driven moves in the quote
Regulatory pressure
Acute toxicity classification raises the compliance cost of producing, storing and moving this material. That cost sits inside the price, and it is one reason capacity has consolidated rather than expanded in some regions.
- Handling obligations vary by jurisdiction
- Some markets restrict certain end uses
- We check destination rules before quoting
Pack format
Cost per kilo falls from 25 kg bags to drums to jumbo bags — and with a toxic fine powder, bulk bags also cut the number of times an operator opens a pack.
- Small bags carry the highest packing cost
- FIBC is cheapest per kilo at volume
- Less manual handling means less exposure
Freight & DG surcharges
This is regulated cargo, so ocean freight carries a hazardous surcharge and space is tighter than for general cargo. Destination and Incoterm move landed cost as much as the ex-works price does.
- Compare on landed cost, not ex-works
- DG space books out ahead of peak season
- We quote FOB, CIF, CFR or DDP as you prefer
Source availability
A plant turnaround, an environmental inspection or a logistics disruption can take capacity offline at short notice. Single-sourced buyers feel this hardest.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
| If your end use is… | Specify |
|---|---|
| Azo pigments & dyes | Colour ceiling, tight isomer limit, low insolubles |
| p-Phenylenediamine chain | High assay, controlled heavy metals for downstream catalysis |
| Corrosion inhibitor chemistry | High assay, tight moisture control |
| Pharmaceutical chain | Tight isomer limit; metals and residues reported |
| Laboratory / R&D | Small pack, high purity, full analytical pack |
Not sure which column you are in? Describe the reaction you are running and our technical desk will recommend the grade — including telling you when a cheaper specification would do the job just as well.
Support that goes beyond shipping the bag
What our technical desk will do
- Match a grade to your reaction. Tell us the step you are running and we will recommend the specification — and say so plainly when a tighter, costlier grade would add nothing.
- Be straight about the hazard profile. We state the acute toxicity classification at enquiry stage so your EHS team can price the controls into the decision, rather than meeting it for the first time on the label.
- Advise on handling and storage for your site conditions — dust control for a fine powder looks different in a humid coastal plant than in a dry inland one.
- Review your specification before it goes into a contract, so you are not locked into a limit that no plant can consistently hit.
Regulatory & compliance notes
- Acute toxicant obligations are jurisdiction-specific. Several regimes impose exposure limits, health surveillance and record retention for chemicals with this hazard profile. Confirm what applies at your site before the first delivery.
- Import controls vary by destination. Some jurisdictions apply registration, licensing or end-use declaration requirements to this material. We check the destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. Confirm your obligations under the applicable inventory regime for your import volume — we will supply the identity data you need for that filing.
- Downstream article restrictions can apply to certain colourant and consumer applications. Your regulatory team should confirm the finished-article position for the end use you have in mind.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import and your workplace. What we commit to is giving you accurate product identity data, an honest statement of the hazard classification and complete documentation to work from.
From enquiry to delivered pallet
Send the specification
Product name or CAS 100-01-6, the assay and colour limits you work to, quantity, pack preference and destination port.
Receive a firm quote
Pricing, lead time, packing and Incoterm confirmed in writing within 24 hours — our sourcing desk is staffed around the clock.
Qualify and approve
Sample dispatched if you are qualifying a new source. Batch COA shared for your approval before the material is released.
Ship and track
DG classification filed, freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
Often bought alongside this grade
Consolidate several intermediates onto one shipment and one invoice. These are the anilines and aromatics our pigment, agrochemical and fine chemical customers most often order in the same programme. Each of the following is part of our wider aniline intermediate range — browse the full product catalogue for current availability and specification sheets.
What buyers ask us about Para Nitroaniline
Is this material a classified toxicant?
Can I use the ortho or meta isomer instead?
What purity do you normally supply?
What is the minimum order quantity?
How long does delivery take?
Why does the powder colour matter so much?
How should we store it, and what is the shelf life?
Is this a dangerous good? What paperwork comes with it?
- Batch certificate of analysis
- GHS-format safety data sheet
- Dangerous-goods declaration with UN number, class and packing group
- Commercial invoice, packing list and bill of lading or airway bill
- Certificate of origin and any destination-specific forms
Do you supply to my country?
Do you manufacture this yourself?
Can you hold stock against a production plan?
Request pricing on Para Nitroaniline
Send your required assay, quantity, pack format and destination port. Our sourcing desk is available 24 hours a day, 7 days a week, and comes back with pricing, lead time and packing options — whether that is a single trial bag or a contracted container programme for the year.