2,5-Dichloroaniline 25DCA · CAS 95-82-9

What is 2,5-Dichloroaniline?

2,5-Dichloroaniline is one of six dichloroaniline isomers, formula C₆H₅Cl₂N, with chlorine atoms at the 2 and 5 positions relative to the amino group. At room temperature it is a colourless to pale crystalline solid, melting around 47–50 °C, and is insoluble in water.

Its primary value is as a diazo-coupling component in azo pigment synthesis. The amine is converted to a diazonium salt and coupled with an acetoacetanilide or similar coupler to build high-performance organic pigments such as Pigment Yellow 10, used in printing inks, plastics and coatings for their brightness and fastness.

Commercially, it is produced by hydrogenation of 1,4-dichloro-2-nitrobenzene, a route that cleanly reduces the nitro group to an amine while leaving both chlorines in place.

2,5-Dichloroaniline carries the general handling considerations typical of a chlorinated aromatic amine — skin and eye irritation and aquatic toxicity — rather than the heightened carcinogen controls that apply to some other aniline derivatives.

Why 2,5-Dichloroaniline specifically

• The specific isomer pigment chemistry needs. Pigment Yellow 10 and related azo pigments are built on the 2,5-dichloroaniline fragment specifically; other dichloroaniline isomers give different coupling behaviour and shade.
• A clean reduction product. Hydrogenation of 1,4-dichloro-2-nitrobenzene gives the amine with the chlorines intact, a reliable and scalable route.
• Predictable diazo coupling. The electron-withdrawing chlorines and the amine's position give a well-characterised, reproducible coupling reaction for pigment manufacturers.
• Broader fine-chemical utility. Beyond pigments, it is also used as a building block in selected agrochemical and specialty-chemical synthesis.

How 2,5-Dichloroaniline is Manufactured

2,5-Dichloroaniline is made on purpose by reduction of the corresponding nitro compound, so supply tracks installed hydrogenation capacity and feedstock dichloronitrobenzene availability.

• Synthesis of 1,4-dichloro-2-nitrobenzene. Chlorination and nitration steps build the dichloronitrobenzene precursor with the correct substitution pattern.
• Catalytic hydrogenation. The nitro group is reduced to an amine under hydrogen with a metal catalyst, giving 2,5-dichloroaniline while leaving both chlorines in place.
• Neutralisation and separation. The reaction mass is neutralised and the amine is separated from catalyst, solvent and any under- or over-chlorinated by-products.
• Purification. The crude amine is purified by recrystallisation or distillation to the target isomer purity.
• Finishing and packing. The purified solid is milled or flaked to the required particle form, then packed.

Typical Commercial Specification

Figures below are representative of commercial-grade 2,5-dichloroaniline. Tell us your downstream route and the grade you need, and we will advise on the specification to order against.

Physical & Chemical Properties

Behaviour in the process

2,5-Dichloroaniline's reactivity is what pigment chemists are buying:

• Diazotisation. The primary amine converts cleanly to a diazonium salt under standard diazotisation conditions, the first step in azo pigment synthesis.
• Predictable coupling. The diazonium salt couples with acetoacetanilide-type couplers to build Pigment Yellow 10 and related azo pigments with a reproducible, well-characterised shade.
• Isomer sensitivity. Shade and fastness in the finished pigment depend on isomer purity, which is why it is specified tightly.
• Low water solubility. As a largely insoluble solid, it is typically processed as a slurry or dissolved in a compatible solvent system before diazotisation.

2,5-Dichloroaniline and the Other Dichloroaniline Isomers

2,5-Dichloroaniline is one of six dichloroaniline isomers, and each leads to a different family of downstream products.

Stated plainly: the dichloroaniline isomers are not interchangeable — pigment shade and coupling behaviour both depend on exactly where the two chlorines sit relative to the amine, so a formulation built around 2,5-dichloroaniline requires that specific isomer.

Industries We Supply 2,5-Dichloroaniline To

The same crystalline amine feeds a pigment manufacturer, a dye-intermediate works and a specialty-chemical producer. What changes is the downstream coupling chemistry and the documentation each requires.

Where 2,5-Dichloroaniline is Used

2,5-Dichloroaniline is bought almost entirely as a diazo-coupling intermediate for azo pigments. These are the end uses our customers build it into.

In pigment manufacture

2,5-Dichloroaniline is diazotised and coupled with an acetoacetanilide-type coupler to build Pigment Yellow 10 and related diarylide pigments. Isomer purity directly affects the shade, strength and fastness of the finished pigment, so manufacturers specify it tightly and reject off-isomer lots before they reach the coupling step.

In dye and specialty-chemical synthesis

Beyond pigments, the same diazo-coupling reactivity is used in selected azo dye syntheses and as a building block in agrochemical and fine-chemical routes where the 2,5-dichloro substitution pattern is specifically required.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis, with isomer content reported alongside purity because shade and coupling behaviour are specific to the 2,5-substitution pattern.

• 2,5-Dichloroaniline content — by gas chromatography, the primary grade measure.
• Isomeric dichloroanilines — reported because other isomers shift shade and reduce coupling yield.
• Melting point — a fast indicator of purity and isomer content.
• Residual dichloronitrobenzene — checked as an incomplete-reduction impurity.
• Moisture — measured to limits relevant to handling and downstream diazotisation.
• Colour — an indicator of thermal history and trace contamination.

Common Process Problems & Likely Causes

When 2,5-dichloroaniline causes trouble, it is usually isomer carry-over, moisture or residual nitro compound. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. HDPE-lined bags or drums, typically 25 kg net, palletised and shrink-wrapped for export.
• Temperature control. Store below the melting point (47–50 °C) and away from direct sun and heat sources.
• Material compatibility. Avoid contact with strong oxidisers and strong acids.
• Environmental segregation. Keep away from waterways and drains in line with its environmental hazard profile.
• Shelf life. Stable in sealed, dry packaging; moisture ingress is the main degradation route for the solid.
• Transport. Confirm the exact classification with your carrier for your shipping lane; it typically moves under standard environmental-hazard precautions rather than the most restrictive dangerous-goods classes.

Hazards & Safe Handling

2,5-Dichloroaniline is harmful by ingestion, inhalation and skin contact, and carries aquatic toxicity considerations typical of chlorinated aromatic amines, which governs both occupational PPE and environmental handling requirements.

• Acute toxicity. Harmful if swallowed, inhaled or absorbed through skin; avoid all three routes of exposure.
• Skin and eye contact. Causes irritation. Wear chemical-resistant gloves and goggles; rinse thoroughly with water on contact.
• Environmental toxicity. Potentially harmful to aquatic organisms. Avoid release to waterways and drains.
• Dust. Avoid generating dust during handling; use local exhaust ventilation where appropriate.
• PPE. Chemical-resistant gloves, goggles and a dust mask for powder handling.
• Waste disposal. Follow local hazardous-waste rules; do not discharge to sewer or waterways.

Regulatory & Compliance Notes

2,5-Dichloroaniline is a registered industrial chemical with standard occupational and environmental handling considerations. Because obligations differ by territory and use, the notes below are orientation rather than legal advice — confirm your own position with your regulatory adviser.

• GHS classification. Typically classified as harmful by multiple routes of exposure, with aquatic toxicity considerations; the SDS carries the full hazard statements for your grade.
• REACH and chemical inventories. Registered under EU REACH and listed on major chemical inventories.
• Pigment end-use regulation. Finished pigments built from this intermediate may carry their own regulatory requirements for use in food-contact packaging, toys or cosmetics, independent of the intermediate itself.
• HS code. Commonly declared under the halogenated aniline derivatives heading; confirm the exact tariff line with your customs broker for your jurisdiction.
• Quality agreements. Pigment and dye producers commonly expect documented isomer and moisture limits and change control. Tell us what your agreement requires.

We Supply 2,5-Dichloroaniline Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship 2,5-Dichloroaniline from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged as routing allows.
• Documentation. Commercial invoice, packing list, certificate of origin, COA and SDS issued as a complete set.
• Flexible volumes. From bag and drum trial quantities up to repeat bulk shipments on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying 2,5-Dichloroaniline from Chelora

We are an independent sourcing and supply partner. For 2,5-dichloroaniline that means settling three things at enquiry: the isomer purity your shade specification requires, the particle form you need, and the quantity you are buying.

• Documentation on every lot. Batch-specific COA with isomer purity, melting point and moisture, plus the current SDS.
• Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
• Quantities. Bag and drum trial quantities through to full bulk shipments on contract supply.
• Inspection. Independent third-party inspection available at loading when the contract requires it.
• Related intermediates. 3,4-Dichloroaniline and PNCB alongside this product from one supplier.

How ordering works

• Send the enquiry. Isomer purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, particle form and a sample COA, normally within one working day.
• Qualify the supply. For first orders or shade-critical applications, we share the analysis so your technical team can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
• Ship and document. Packed, labelled and loaded with the full export document set, and tracked through to arrival.

Related Dichloroaniline Isomers & Intermediates

Buyers of 2,5-dichloroaniline often source other dichloroaniline isomers or related aniline intermediates alongside it. Consolidating them cuts freight cost and gives you a single point of contact for documentation.