Ortho Chloro Para Nitro Aniline
Ortho Chloro Para Nitro Aniline — OCPNA or 2-chloro-4-nitroaniline — is a chloronitroaniline widely used as an intermediate in dye and pharmaceutical manufacture. The chlorine ortho to the amine and the nitro group para to it give this isomer its own distinct reactivity and shade character within the chloronitroaniline family.
Chelora Chemicals supplies OCPNA to dye manufacturers and pharmaceutical intermediate producers worldwide, in bags, drums and container quantities, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 121-87-9
- IUPAC name
- 2-Chloro-4-nitroaniline
- Molecular formula
- C6H5ClN2O2
- Molecular weight
- 172.57 g/mol
- EC / EINECS
- 204-502-2
- MDL number
- MFCD00007665
- SMILES
- Nc1ccc([N+](=O)[O-])cc1Cl
- UN Number
- UN 2237
* Confirm the exact HS heading with your customs broker — classification of chloronitroaniline derivatives varies between destination tariffs.
What OCPNA is used for
Ortho Chloro Para Nitro Aniline places a chlorine ortho to the amine and a nitro group para to it. That geometry is different from the meta-nitro and other chloronitroaniline patterns in our range, and it gives OCPNA its own reactivity profile — a moderately deactivated ring, a distinctive yellow-to-orange colour, and a melting point around 107 °C that sits between the lighter and heavier chlorinated grades.
In practice OCPNA is bought as an intermediate for dye manufacture and for pharmaceutical intermediate synthesis, where the amine, chlorine and nitro group each offer a distinct handle for further chemistry.
Where it sits in the chloronitroaniline family
- 2-Chloro-4-nitroaniline / OCPNA (CAS 121-87-9) — this product. Chlorine ortho, nitro para, relative to the amine.
- 4-Chloro-2-nitroaniline / PCONA (CAS 89-63-4) — the reverse pattern, chlorine para and nitro ortho; see our separate product page for that grade, widely used as the azoic diazo base for Fast Red 3GL.
- Other chloronitroaniline isomers — each pattern serves a distinct set of dye and pharmaceutical routes; the isomers are not interchangeable.
If your purchase order simply says "chloronitroaniline", quote us the CAS number and we will confirm the correct isomer before the order is placed. We supply the sister isomers as well — see our full chloronitroaniline range.
Appearance and handling character
OCPNA ships as a yellow to orange crystalline powder melting around 107 °C, with low water solubility (about 0.23 g/L) and correspondingly better solubility in common organic solvents. It is stable under normal storage but incompatible with strong oxidising agents and strong acids or bases. Read the safety section below before planning any handling — this material is harmful if swallowed and toxic to aquatic life with long-lasting effects, and that should shape your controls from the outset.
| Parameter | Typical value |
|---|---|
| Appearance | Yellow crystalline powder |
| Assay (GC) | 98.0% min |
| Melting range | 105 – 111 °C |
| Moisture | 0.5% max |
| Isomeric impurities | Reported per batch |
| Non-volatile 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 or a specific colour ceiling, send us the specification and we will quote against it rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Crystalline powder at ambient |
| Melting point | ≈ 106 – 109 °C |
| Boiling point | ≈ 320 °C (decomposes) |
| Flash point | ≈ 193 °C |
| Relative density | ≈ 1.5 |
| Water solubility | ≈ 0.23 g/L (20 °C) |
| Organic solubility | Soluble in common organic solvents |
Physical constants compiled from public reference data for CAS 121-87-9 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
OCPNA's volume is concentrated in dye manufacture, with a meaningful outlet in pharmaceutical intermediate synthesis.
Azo & other dye chemistry
OCPNA is diazotised or otherwise incorporated into dye and colourant synthesis, where the ortho-chloro, para-nitro pattern gives a distinct shade compared with other chloronitroaniline isomers.
- Dye intermediate chemistry
- Isomer content shows up directly as off-shade
- See our full dye intermediate range
Pharmaceutical intermediates
The amine, chlorine and nitro group each provide a handle for pharmaceutical intermediate synthesis — amide formation, ring construction or N-arylation routes that need this specific substitution pattern.
- Amide, urea and heterocyclic construction
- GMP-adjacent documentation available on request
Agrochemical & specialty chemistry
The reactive functional groups on this ring also support its use as a building block in certain agrochemical and specialty-chemical synthesis routes.
- Agrochemical intermediate synthesis
- See our agrochemical intermediate range
Fine & custom synthesis
A well-characterised chloronitroaniline building block for custom research chemistry, ligand synthesis and process development where this specific substitution pattern is required.
- Custom research and process-development quantities
- Technical desk support on new routes
Analytical & reference standards
Recognised as a reference compound in analytical chemistry and residue analysis method development, supplied at defined purity for calibration and validation work.
- Analytical reference standard
- High-purity lots available on request
Contract & scheduled supply
Dye and pharmaceutical intermediate plants run to production campaign, not calendar month. We hold inventory and release it against your production plan rather than in one shipment.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply OCPNA
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no chlorination or nitration plant — and for an isomer-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 isomer tolerance, your price point and your delivery window.
We keep a second qualified source on this line, so a plant disruption does not stall your production schedule.
- Specification read against the CAS first. We confirm you need 121-87-9 and not the 4-chloro-2-nitro isomer or another chloronitroaniline before we quote a price.
- Batch COA shared before dispatch. You approve the assay, melting range and colour against your own spec while the material is still in our warehouse.
- Hazard status stated up front. We say what the classification is 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.
- 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 OCPNA 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 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 batch-wise charging.
Fibre & HDPE drums
UN-certified drums with liner for longer sea transits and humid destinations, meeting the packing requirements for this hazard classification.
Jumbo / FIBC bags
Bulk bags with liner for high-volume users with mechanical charging. Fewer handling movements 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 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
Dye and pharmaceutical-intermediate production runs to campaign. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Handle it as a classified aromatic amine
OCPNA is harmful if swallowed and toxic to aquatic life with long-lasting effects. 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 disposal planning.
Classified hazards
H302Harmful if swallowed.H411Toxic to aquatic life with long lasting effects.
Hazard statements reflect the harmonised classification commonly published for CAS 121-87-9. 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 toxic to aquatic life with long-lasting effects. Collect spilled solid mechanically into a labelled container; never wash it to a drain.
- Suppress dust. Dry sweeping of a fine solid generates an inhalable aerosol — use vacuum collection or dampen carefully in line with the SDS.
- Wash contaminated skin promptly and remove contaminated clothing, as standard practice for any aromatic amine.
- Have the SDS with the casualty. The treating clinician needs the product identity and CAS number in hand.
- Never discharge to drain or watercourse. H411 applies — collect spills as solid waste and dispose of them as regulated chemical waste.
Storage
- Cool, dry, well-ventilated store, away from direct sunlight and heat sources. The melting point is only about 107 °C, so an uncooled store in a hot climate can soften or fuse the contents.
- Keep containers tightly closed and segregated from oxidising agents, strong acids and strong bases.
- Shelf life is typically 12–24 months in sealed original packing under these conditions. Re-assay before use after long storage.
Handling & PPE
- Standard dust and skin control for a fine aromatic-amine powder — chemical-resistant gloves, eye protection and, where dust is generated, respiratory protection.
- Wash hands before eating, drinking or smoking after handling, as with any dye or pharmaceutical intermediate.
- Never discharge to drain or watercourse. H411 applies — collect spills and rinse water for disposal as regulated chemical waste.
Transport
OCPNA moves as regulated cargo under UN 2237. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made — 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, 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 2237 declared correctly, with IMDG or IATA paperwork 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.
What actually moves the price of this intermediate
OCPNA 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.
Dye & pharma demand cycles
Demand tracks dye-manufacture and pharmaceutical-intermediate production, which each run to their own campaign patterns.
- Quote early for campaign tonnage
- Contracted call-off smooths the exposure
Upstream feedstock
The route back to this molecule runs through chlorobenzene and nitration–reduction chemistry. Movements in benzene, chlorine and nitric acid feed through within a quarter or so.
- Chlorine and benzene set the floor
- We flag feedstock-driven moves in the quote
Pack format
Cost per kilo falls from 25 kg bags to drums to jumbo bags. Bulk formats 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
Freight & DG surcharges
This is regulated cargo under UN 2237, so ocean freight carries a hazardous surcharge and space is tighter than for general cargo.
- Compare on landed cost, not ex-works
- We quote FOB, CIF, CFR or DDP as you prefer
Source availability
A plant turnaround or a feedstock disruption can take capacity offline at short notice. Single-sourced buyers feel this hardest.
- We hold a second qualified source on this line
- Ask us about dual-source contracts
Purity tier
Pharmaceutical-intermediate use typically demands tighter isomer and residue limits than dye-grade material, which shifts the quote accordingly.
- Tell us your end use and we quote the right tier
- Overspecifying a dye-grade order wastes money
From enquiry to delivered pallet
Send the specification
Product name or CAS 121-87-9, 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. Browse our full range of chloronitroaniline and nitroaniline intermediates — our sourcing desk will confirm exact availability and specification against the CAS number you need.
What buyers ask us about OCPNA
Is OCPNA the same as PCONA (Para Chloro Ortho Nitro Aniline)?
What purity do you normally supply?
What is the minimum order quantity?
How long does delivery take?
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 OCPNA
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.