Ortho Nitroaniline
Ortho Nitroaniline — ONA or 2-nitroaniline — is the orange-yellow crystalline intermediate that sits one hydrogenation step away from ortho-phenylenediamine, and from there the whole benzimidazole family: carbendazim and its relatives, corrosion inhibitors, rubber accelerators and UV stabilisers. It is also a long-standing diazo component in azo colour chemistry.
Chelora Chemicals supplies ONA to dye and pigment houses, agrochemical producers and fine chemical manufacturers worldwide, in bags, drums and container quantities, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 88-74-4
- IUPAC name
- 2-Nitroaniline
- Molecular formula
- C6H6N2O2
- Molecular weight
- 138.12 g/mol
- EC / EINECS
- 201-855-4
- MDL number
- MFCD00007748
- SMILES
- Nc1ccccc1[N+](=O)[O-]
- HS Code
- 2921 42*
* Confirm the exact HS heading with your customs broker — classification of nitrated aniline derivatives varies between destination tariffs.
What Ortho Nitroaniline is used for
Ortho Nitroaniline carries an amino group and a nitro group on adjacent ring positions. That ortho relationship is the entire commercial point of the molecule. Two functional groups sitting next to each other on a benzene ring is exactly the geometry you need to close a five-membered heterocycle — which is why this compound is the industrial gateway to benzimidazole chemistry.
In practice ONA is a captive intermediate. The largest volumes are hydrogenated to ortho-phenylenediamine (OPD), and OPD is then cyclised into benzimidazoles: carbendazim and the related fungicides, 2-mercaptobenzimidazole for rubber, benzotriazole corrosion inhibitors, and benzimidazole-based UV stabilisers. A second, older outlet diazotises ONA directly as a coupling partner in azo dyes and pigments.
Why the isomer matters
The three nitroaniline isomers are not substitutes for one another — and unlike the chloroanilines, they behave visibly differently, which is a small mercy:
- Ortho nitroaniline (CAS 88-74-4) — this product. Amino and nitro adjacent. The route to o-phenylenediamine and benzimidazoles.
- Meta nitroaniline (CAS 99-09-2) — the 1,3 pattern. Used in azo dye chemistry; cannot close a benzimidazole ring.
- Para nitroaniline (CAS 100-01-6) — the 1,4 pattern, and the highest-volume of the three. Feeds p-phenylenediamine, azo dyes and antioxidant 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. We supply the sister isomers as well, so there is nothing to gain from guessing.
Appearance and handling character
ONA ships as a bright orange to yellow crystalline solid or powder melting around 71 °C. The colour is intrinsic to the molecule, not a sign of degradation — but it does mean the material stains strongly: skin, clothing, flooring and equipment. Treat visible staining on a glove or sleeve as evidence of contact rather than as a cosmetic nuisance, because nitroanilines are absorbed through skin. It is only slightly soluble in water and dissolves readily in alcohols, ketones and aromatic solvents. Because the melting point sits just above 70 °C, an uncooled container on a tropical routing can soften or fuse the contents.
| Parameter | Typical value |
|---|---|
| Appearance | Orange to yellow crystals / powder |
| Assay (GC) | 99.0% min |
| Moisture (KF) | 0.5% max |
| Melting range | 70 – 73 °C |
| Total isomeric impurities | 1.0% max |
| Insolubles / residue | 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 specific isomer limit, a controlled moisture figure or a residue ceiling, 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 | ≈ 71 °C |
| Boiling point | ≈ 284 °C @ 760 mmHg |
| Flash point | ≈ 168 °C |
| Relative density | ≈ 1.44 |
| Partition coeff. (log P) | ≈ 1.85 |
| Water solubility | Slightly soluble (≈ 1 g/L) |
| Organic solubility | Soluble in alcohols, ketones, aromatic & chlorinated solvents |
| Colour | Intrinsic orange-yellow; stains readily |
Physical constants compiled from public reference data for CAS 88-74-4 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
Most ONA consumption runs through the phenylenediamine route into heterocyclic chemistry. The balance is spread across azo colourants and specialty synthesis.
Ortho-phenylenediamine
The dominant outlet. Catalytic hydrogenation of the nitro group gives OPD, the diamine whose two adjacent amines close into benzimidazole, benzotriazole and quinoxaline rings. Almost every other use on this page is downstream of this one step.
- Largest single source of ONA demand
- Catalyst poisons in the feed are the critical risk
- Assay and residue profile drive hydrogenation yield
Benzimidazole fungicides
Through OPD, ONA feeds the benzimidazole fungicide family — carbendazim and its relatives — used across cereals, fruit, vegetables and post-harvest treatment. A long chain, but one where feed quality is still traceable in the finished active.
- Cyclisation of OPD to the benzimidazole core
- Isomeric carry-through shows in the active
- See our agrochemical intermediate range
Azo dyes & pigments
Diazotised directly and coupled onto naphthols or acetoacetarylides to build orange and red azo colourants. The ortho nitro group pulls electron density from the diazonium and shifts the absorption of the finished chromophore.
- Azo diazo component
- Orange and red shade ranges
- See also 2,5-dichloroaniline
Corrosion inhibitors & UV stabilisers
Benzotriazole corrosion inhibitors for copper and its alloys, and benzotriazole-class UV absorbers for coatings and polymers, both trace back through OPD to this aniline.
- Copper and brass corrosion inhibition
- Polymer and coating UV protection
- Water treatment and metalworking chemistry
Rubber & polymer additives
2-Mercaptobenzimidazole and related heterocyclic antioxidants for elastomers are built from the same OPD intermediate — a steady, lower-volume outlet that usually runs at technical rather than pharmaceutical purity.
- Heterocyclic antioxidant synthesis
- Tyre and technical rubber chains
- Looser colour tolerance than pharma use
Contract & scheduled supply
Hydrogenation plants run to campaign, not to a calendar month. Most ONA 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 Ortho Nitroaniline
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no nitroaniline plant — and for a hydrogenation feedstock 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 residue tolerance, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, or a monsoon disrupts a road corridor, your campaign switches source rather than stalling with a hydrogenator standing idle.
- Specification read against the CAS first. We confirm you need 88-74-4 and not the meta or para isomer before we quote a price.
- Batch COA shared before dispatch. You approve the assay, moisture and impurity profile against your own spec while the material is still in our warehouse.
- Catalyst-sensitive buyers taken seriously. If sulphur or heavy-metal traces would poison your hydrogenation catalyst, tell us and we will source and test against that limit.
- 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 for your climate. With a melting point just above 70 °C, pack format and stowage matter on a tropical routing. We plan both with you.
- 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 ONA 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 and your handling effort. Tell us how the material will be charged at your end and we will quote the format that suits your operation — not just the one that suits ours.
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, and far less staining risk in handling.
Jumbo / FIBC bags
Bulk bags with liner for high-volume hydrogenation users with mechanical charging. Fewer handling movements, less operator contact and 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 — and check it against your catalyst — before committing to 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
Hydrogenation 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 skin-absorbable nitroaromatic
ONA is not a benign colourant. Nitroanilines are absorbed through intact skin and can cause methaemoglobinaemia — the blood's oxygen-carrying capacity is impaired, and the onset can be delayed by hours after an exposure that seemed trivial. 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 and emergency planning.
Classified hazards
H302Harmful if swallowed.H312Harmful in contact with skin.H332Harmful if inhaled.H411Toxic to aquatic life with long lasting effects.
Hazard statements reflect the GHS classification commonly published for CAS 88-74-4. Supplier classifications differ in detail, and some assign a stricter acute toxicity category; 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.
- Treat staining as exposure. An orange mark on a glove, sleeve or forearm means contact has happened. Wash immediately and change out of contaminated clothing rather than finishing the shift in it.
- Watch for delayed symptoms. Methaemoglobinaemia can present hours after exposure — headache, breathlessness, a blue-grey tinge to lips or fingertips. Anyone with those signs needs medical attention, not a rest break.
- Sweep, do not hose. The material is toxic to aquatic life. Collect spilled solid mechanically into a labelled container; never wash it to a drain.
- Have the SDS with the casualty. The treating clinician needs the product identity, the CAS number and the words "nitroaromatic, methaemoglobin former" in front of them.
- Dispose as regulated waste through a licensed contractor, in line with your local chemical waste regulations.
Storage
- Cool, dry, well-ventilated store, away from direct sunlight and heat sources. The melting point is only about 71 °C, so an uncooled store in a hot climate can fuse the contents into a cake.
- Keep containers tightly closed. Open packing picks up moisture, which carries forward into a hydrogenation step where water is rarely welcome.
- Segregate from strong oxidising and reducing agents, strong acids and bases. Nitroaromatics warrant more caution around oxidisers than a plain aniline does.
- Bunded, sealed-floor storage. The compound is toxic to aquatic life, and it stains any porous floor it reaches.
- Shelf life is typically 24 months in sealed original packing under these conditions. Re-assay before use after long storage.
Handling & PPE
- Skin protection is the priority. Nitroanilines pass through intact skin — chemical-resistant gloves and coveralls, not just splash protection, and a hard rule against working in stained clothing.
- Engineering controls first. Charge under local exhaust ventilation or in a closed transfer system; ONA has little odour warning at exposure-relevant levels.
- Respiratory protection where dust may be generated — particularly when breaking a caked drum or emptying a bulk bag — per your own exposure assessment.
- Health surveillance. For routine handlers, many operators include methaemoglobin monitoring in occupational health screening. That call belongs to your OH provider, not to us.
- Never discharge to drain or watercourse. H411 applies — collect spills as solid waste and dispose of them as regulated chemical waste.
Transport
ONA 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 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.
How this nitroaniline becomes a benzimidazole
Understanding what happens to ONA downstream explains why the specification matters so much — and why an apparently small impurity in the feed shows up as a poisoned catalyst or a failed cyclisation two steps later. The route below is the general industrial pattern, not a process disclosure.
Start with the ortho pair
ONA carries an amine and a nitro group on adjacent carbons. That adjacency is the whole reason this isomer, and not the meta or para one, opens the heterocyclic route.
Hydrogenate to the diamine
Catalytic hydrogenation reduces the nitro group to an amine, giving ortho-phenylenediamine. Sulphur and heavy-metal traces in the feed poison the catalyst and cost you a charge.
Cyclise
The two adjacent amines close onto a one-carbon partner — cyanamide, urea, an acid or a carbamate — to form the benzimidazole ring that defines the whole product family.
Derivatise or formulate
The heterocycle is then substituted into a fungicide, a corrosion inhibitor, a UV absorber or a rubber antioxidant, and purified to the grade the end market demands.
Why feed quality carries through the whole route
The hydrogenation step is the choke point. Anything in the feed that reaches the catalyst surface, or that survives reduction with its own reactive functionality intact, follows the material down the line:
- Catalyst poisons — sulphur species and certain metal traces — deactivate the hydrogenation charge. The cost is not the impurity, it is the catalyst and the lost campaign hours.
- Isomeric nitroanilines reduce to the wrong phenylenediamine, which cannot close the ring and simply consumes hydrogen and reactor volume.
- Residual water is tolerable in reduction but rarely welcome in the cyclisation step that follows, where it competes with the ring-closing partner.
- Heavy residues concentrate in the still bottoms and reduce the number of passes you get from a distillation or crystallisation train.
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 |
|---|---|
| Ortho Nitroaniline CAS 88-74-4 — this product | o-Phenylenediamine Benzimidazoles Azo dyes & pigments |
| Meta Nitroaniline CAS 99-09-2 | Azo dye intermediates m-Phenylenediamine route |
| Para Nitroaniline CAS 100-01-6 | p-Phenylenediamine Azo dyes Antioxidant chemistry |
If your route calls for a different isomer or a related aromatic amine, we supply those as well — see the full intermediate range. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
ONA 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.
Downstream demand cycles
Fungicide manufacture is seasonal and colour demand tracks coatings and packaging, so two different downstream cycles pull on the same aniline at different times of year.
- Quote early for pre-season fungicide tonnage
- Spot buying at peak costs materially more
- Contracted call-off smooths the exposure
Upstream feedstock
The route back to ONA runs through chlorobenzene and the nitration chain. Movements in benzene, chlorine, nitric acid and ammonia feed through to the nitroaniline within a quarter or so.
- Nitration chain sets the floor
- Energy cost weighs on the whole route
- We flag feedstock-driven moves in the quote
Specification tier
Hydrogenation-grade material with limits on catalyst poisons prices above technical grade destined for direct diazotisation. Paying for a spec you do not need is a common and avoidable cost.
- Tell us the end use, not just the purity
- Dye-grade tolerances are usually looser
- We will say when a tighter spec is unnecessary
Pack format
Cost per kilo falls from 25 kg bags to drums to jumbo bags — and with a staining solid, bulk bags also cut operator contact. If your charging system can take one, take it.
- 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 monsoon 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 |
|---|---|
| Hydrogenation to OPD | High assay, low catalyst poisons, controlled moisture |
| Benzimidazole fungicides | As above, with a tight isomer limit |
| Azo dyes & pigments | Consistent assay; residue and insolubles limit |
| Rubber & polymer additives | Technical grade; looser tolerances acceptable |
| 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.
- Take your catalyst seriously. If your hydrogenation charge is sensitive to particular trace species, we will source and test against that limit rather than shipping a generic technical grade.
- Advise on handling and storage for your site conditions — a bagged store in a Gulf summer is a different problem from one in northern Europe, especially for a solid that melts at 71 °C.
- 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
- Import controls vary by destination. Nitroaromatics attract registration, licensing or end-use declaration requirements in some jurisdictions. 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.
- Occupational exposure limits for nitroanilines are set nationally and are often accompanied by a skin notation. Your EHS team should confirm the limit and the monitoring expectation that applies at your site.
- Dangerous goods documentation is prepared by our export desk and filed before booking, so the consignment is not held at origin for paperwork.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import. What we commit to is giving you accurate product identity data and complete documentation to work from.
From enquiry to delivered pallet
Send the specification
Product name or CAS 88-74-4, the assay and impurity 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 or testing against your catalyst. 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 dye, agrochemical and fine chemical customers most often order in the same programme.
What buyers ask us about Ortho Nitroaniline
Can I use meta or para nitroaniline instead?
What purity do you normally supply?
Can you supply against a catalyst-poison specification?
What is the minimum order quantity?
How long does delivery take?
The product is bright orange. Is that normal?
The material arrived caked or partly fused. Is it off-spec?
What are the specific health precautions we should plan for?
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 Ortho 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.