2,5-Dichloroaniline
2,5-Dichloroaniline — 2,5-DCA in the trade — is a colour-industry workhorse. Diazotised and coupled, it builds the azo pigments and dyes whose shade strength, heat stability and migration resistance depend directly on the isomeric cleanliness of the aniline they started from.
Chelora Chemicals supplies 2,5-DCA 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
- 95-82-9
- IUPAC name
- 2,5-Dichloroaniline
- Molecular formula
- C6H5Cl2N
- Molecular weight
- 162.02 g/mol
- EC / EINECS
- 202-450-5
- MDL number
- MFCD00007605
- SMILES
- Nc1cc(Cl)ccc1Cl
- HS Code
- 2921 42*
* Confirm the exact HS heading with your customs broker — classification of halogenated aniline derivatives varies between destination tariffs.
What 2,5-Dichloroaniline is used for
2,5-Dichloroaniline is an ortho-para dichlorinated aromatic amine — chlorine sits next to the amine at position 2 and across the ring at position 5. That arrangement is the commercial point of the molecule. The ortho chlorine crowds the diazonium group and steadies it; the second chlorine pulls electron density out of the ring. Together they shift the absorption of the finished azo colourant and lift its fastness properties.
In practice 2,5-DCA is a captive intermediate: pigment and dye plants buy it to diazotise and couple. Its principal commercial home is azo colour chemistry — pigments for inks, coatings and plastics, and disperse and solvent dyes — with a secondary role as a building block in agrochemical and pharmaceutical synthesis.
Why the isomer matters
"Dichloroaniline" on its own is not a specification. Six isomers exist, they look identical on a packing list, and in colour work the wrong one does not simply fail — it produces an off-shade batch that looks plausible until it is measured:
- 2,5-Dichloroaniline (CAS 95-82-9) — this product. The azo colour intermediate.
- 3,4-Dichloroaniline (CAS 95-76-1) — the phenylurea herbicide intermediate, for diuron and propanil. See our 3,4-dichloroaniline page.
- 2,4-Dichloroaniline (CAS 554-00-7) — a third pattern used across both dye and agro chemistry, and not a substitute for either of the above.
If your purchase order simply says "DCA", 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
2,5-DCA ships as a white to pale brown crystalline solid or flake with a melting point around 50 °C — low enough that an uncooled container on a tropical routing will very likely soften or fuse it. Material that has melted and re-set is chemically unchanged but can arrive as a single cake, so pack format and stowage are worth planning rather than leaving to the freight desk. It is only slightly soluble in water and dissolves readily in alcohols, ketones and aromatic solvents. Like all anilines it darkens on exposure to air and light — and in colour work that drift is not cosmetic, so specify a colour ceiling if your process is sensitive.
| Parameter | Typical value |
|---|---|
| Appearance | White to pale brown crystals / flakes |
| Assay (GC) | 99.0% min |
| Moisture (KF) | 0.3% max |
| Melting range | 48 – 51 °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 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 | ≈ 50 °C |
| Boiling point | ≈ 251 °C @ 760 mmHg |
| Flash point | ≈ 112 °C |
| Relative density | ≈ 1.54 |
| Partition coeff. (log P) | ≈ 2.7 |
| Water solubility | Slightly soluble |
| Organic solubility | Soluble in alcohols, ketones, aromatic & chlorinated solvents |
| Odour | Faint, amine-like |
Physical constants compiled from public reference data for CAS 95-82-9 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
Most 2,5-DCA consumption goes into azo colour chemistry. The balance runs through agrochemical, pharmaceutical and specialty synthesis where the 2,5-pattern is needed on the ring.
Azo pigments
The dominant outlet. Diazotised 2,5-DCA is coupled onto acetoacetarylide or naphthol components to build insoluble monoazo pigments for printing inks, coatings and plastics. The chlorines raise heat stability and cut migration in polymer systems.
- Largest single source of 2,5-DCA demand
- Isomer content shows up directly as off-shade
- Colour of the feed matters as much as assay
Disperse & solvent dyes
As a diazo component in disperse dyes for polyester and in solvent dyes for inks and plastics. Halogen substitution deepens shade and improves sublimation and light fastness relative to unsubstituted aniline.
- Polyester disperse ranges
- Solvent and plastic colourants
- Sublimation fastness improvement
Phenylhydrazine derivatives
Diazotisation followed by reduction gives 2,5-dichlorophenylhydrazine, a building block for pyrazoles, indoles and heterocyclic systems used across agrochemical and pharmaceutical discovery and manufacture.
- Pyrazole and indole ring construction
- Heterocyclic active ingredient routes
- Purity of the aniline sets the hydrazine quality
Agrochemical intermediates
Used where a 2,5-dichlorophenyl fragment is required on the finished active — through acylation, urea formation or heterocyclic ring building rather than as a direct precursor to any single large-volume herbicide.
- Anilide and urea chemistry
- Custom intermediate synthesis
- See also 3,4-dichloroaniline
Fine & specialty synthesis
A substituted aniline building block for custom amides, sulfonamides and ligand work where the 2,5-substitution pattern is needed to control electronics and steric access at nitrogen.
- Custom amide and sulfonamide formation
- Research and pilot-scale chemistry
- Available in trial and laboratory quantities
Contract & scheduled supply
Pigment plants run shade campaigns, not continuous single-product output. Most 2,5-DCA 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 2,5-Dichloroaniline
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no dichloroaniline plant — and for a colour-critical 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 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 a monsoon disrupts a road corridor, your shade campaign switches source rather than stalling mid-programme.
- Specification read against the CAS first. We confirm you need 95-82-9 and not one of the other five dichloroaniline isomers 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.
- Shade continuity taken seriously. Where a colour house has qualified a source, we work to keep you on it rather than rotating suppliers batch to batch.
- Pre-shipment samples for qualification. New account or new source, your laboratory runs a coupling trial before the full quantity ever moves.
- Packing chosen for your climate. With a melting point near 50 °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 2,5-DCA 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, air ingress and colour drift than bagged material.
Jumbo / FIBC bags
Bulk bags with liner for high-volume users with 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 colour laboratory can run a coupling trial 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 plants run to shade campaigns. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Handle this as a toxic, absorbable amine
2,5-DCA is not a benign solid. Like the chloroanilines generally, it is acutely toxic by all three routes, readily absorbed through intact skin, and harmful to aquatic life. 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
H301Toxic if swallowed.H311Toxic in contact with skin.H331Toxic if inhaled.H411Toxic to aquatic life with long lasting effects.
Hazard statements reflect the GHS classification commonly published for CAS 95-82-9. 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. 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.
- Assume skin absorption. Contaminated clothing is a continuing exposure route — remove it immediately and wash the skin thoroughly.
- Have the SDS with the casualty. Chloroanilines can cause methaemoglobinaemia, and the treating clinician needs the product identity and CAS number in hand.
- 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 50 °C, so an uncooled store in a hot climate will fuse the contents.
- Keep containers tightly closed. Air and light drive colour drift, and in colour chemistry that drift is not cosmetic. An open bag also picks up moisture.
- Segregate from oxidising agents, strong acids, nitrites and acid chlorides. As a primary aromatic amine it reacts exothermically with acylating and oxidising reagents.
- Bunded, sealed-floor storage. The compound is toxic to aquatic life — containment matters more than dilution in a spill scenario.
- Shelf life is typically 12–24 months in sealed original packing under these conditions. Re-assay and re-check colour before use after long storage.
Handling & PPE
- Skin protection is the priority. Chloroanilines are absorbed through intact skin — chemical-resistant gloves and coveralls, not just splash protection.
- Engineering controls first. Charge under local exhaust ventilation or in a closed transfer system; the faint odour is no warning of exposure at all.
- Respiratory protection where dust or vapour may be generated — particularly when breaking a caked drum — per your own exposure assessment.
- Diazotisation is exothermic. Temperature control and nitrite dosing discipline belong in your own process safety assessment before the first batch.
- Never discharge to drain or watercourse. H411 applies — collect spills as solid waste and dispose of them as regulated chemical waste.
Transport
2,5-DCA 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 aniline becomes an azo colourant
Understanding what happens to 2,5-DCA downstream explains why the specification matters so much — and why an apparently small impurity in the aniline shows up as an off-shade batch two steps later. The route below is the general industrial pattern, not a process disclosure.
Charge and dissolve
The aniline is slurried or dissolved in mineral acid. Insolubles and heavy residues in the feed carry straight through into the finished pigment as filtration burden.
Diazotise
Sodium nitrite at low temperature converts the amine to the diazonium salt. The ortho chlorine helps steady it, but temperature and acid strength still govern the yield.
Couple
The diazonium salt is coupled onto a naphthol or acetoacetarylide component. Any competing aniline in the feed couples in parallel and produces a second, off-shade chromophore.
Finish and standardise
The crude colourant is filtered, washed, dried and milled, then standardised to a shade target against the reference — where isomer-driven drift finally becomes visible.
Why aniline quality carries through the whole route
Every step acts on the nitrogen. Anything in the feed that competes for that nitrogen, or that carries its own reactive functionality, follows the material down the line:
- Isomeric anilines diazotise and couple in parallel, giving a second chromophore with a different absorption maximum. The result is a shade that cannot be corrected by standardisation alone.
- Residual water is less critical here than in isocyanate chemistry but still dilutes the acid charge and shifts the nitrite stoichiometry.
- Oxidation products — the coloured species responsible for the brown drift — dull the finished shade and cost you strength.
- Insolubles and heavy residues add filtration load, lengthen the batch cycle and can show as specks in a let-down.
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 |
|---|---|
| 2,5-Dichloroaniline CAS 95-82-9 — this product | Azo pigments Disperse & solvent dyes Phenylhydrazine derivatives |
| 3,4-Dichloroaniline CAS 95-76-1 | Diuron Linuron Propanil |
| Ortho Nitroaniline CAS 88-74-4 | Azo dyes & pigments o-Phenylenediamine route |
If your route calls for one of the others, we supply those as well — see 3,4-dichloroaniline and ortho nitroaniline. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
2,5-DCA 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 colour demand
Pigment demand tracks coatings, packaging ink and plastics output, so construction and consumer packaging cycles reach back to the aniline within a quarter or two.
- Ink and coatings cycles drive volume
- Shade campaigns concentrate demand
- Contracted call-off smooths the exposure
Upstream feedstock
The route back to 2,5-DCA runs through chlorinated benzenes and the nitration–reduction chain. Movements in benzene, chlorine and hydrogen feed through to the aniline within a quarter or so.
- Chlorine and benzene set the floor
- Energy cost weighs on distillation
- We flag feedstock-driven moves in the quote
Specification tier
Pigment-grade material with a colour ceiling and a tight isomer limit prices above technical grade destined for general synthesis. Paying for a spec you do not need is a common and avoidable cost.
- Tell us the end use, not just the purity
- Technical grade suits non-colour outlets
- We will say when a tighter spec is unnecessary
Pack format
Cost per kilo falls from 25 kg bags to drums to jumbo bags. If your charging system can take a bulk bag, the saving over a campaign usually dwarfs the handling change.
- Small bags carry the highest packing cost
- FIBC is cheapest per kilo at volume
- Disposal of packing is a hidden cost at your end
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 — and a source change mid-shade is its own problem.
- 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 | Colour ceiling, tight isomer limit, low insolubles |
| Disperse & solvent dyes | As above, with shade consistency batch to batch |
| Phenylhydrazine derivatives | High assay; heavy-ends limit worth setting |
| Agrochemical intermediates | High assay and controlled moisture |
| 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.
- Protect your shade continuity. Where a colour house has qualified a particular source, we work to keep you on it and flag in advance when a switch is unavoidable.
- 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 melting near 50 °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. Chlorinated anilines 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.
- Textile and article restrictions can apply downstream of azo colourants depending on the end market. Your regulatory team should confirm the finished-article position for the shade you are building.
- 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 95-82-9, the assay, colour 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 for your coupling trial 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 and dye customers most often order in the same programme.
What buyers ask us about 2,5-Dichloroaniline
Is 2,5-DCA interchangeable with 2,4- or 3,4-dichloroaniline?
What purity do you normally supply?
Will a source change affect my shade?
What is the minimum order quantity?
How long does delivery take?
The material arrived caked or partly fused. Is it off-spec?
Why does the solid darken in storage, and does it matter?
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 2,5-Dichloroaniline
Send your required assay, colour ceiling, 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.