2,6-Dichloro-4-Nitroaniline

2,6-Dichloro-4-nitroaniline (DCPNA, dicloran) · CAS 99-30-9

2,6-Dichloro-4-Nitroaniline is the doubly chlorinated nitroaniline behind the orange and yellow-brown shades of the polyester range. The two chlorines flanking the amino group make it a weak base but a strongly electrophilic diazo component, so it couples cleanly onto N,N-dialkylaniline couplers to give Disperse Orange 37/76, Disperse Orange 30 and Disperse Brown 1. Chelora Dyes supplies it lot-tested with batch data and a Safety Data Sheet on every shipment, so your diazotisation starts from a consistent, characterised material.

Also sold as: 2,6-Dichloro-4-nitroaniline · DCPNA · DCNA · Dicloran · 4-Amino-3,5-dichloronitrobenzene

CAS number: 99-30-9
Molecular formula: C₆H₄Cl₂N₂O₂
Molecular weight: 207.01 g/mol
Appearance: Yellow crystalline powder

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Structure of 2,6-Dichloro-4-Nitroaniline

Benzene ring with NH₂, two Cl and NO₂ substituents

NH₂ amino group — diazotised to form the diazonium salt Cl × 2 flank the amine, lower its basicity and shift the dye shade NO₂ nitro group — strong electron acceptor, reducible to NH₂

Key derivatives: Disperse Orange 37/76 Disperse Orange 30 Disperse Brown 1 2,6-Dichloro-PPD

What 2,6-Dichloro-4-Nitroaniline is

A yellow crystalline nitroaniline carrying two chlorine atoms ortho to the amino group and a nitro group para to it. It is used chiefly as a diazo component for orange and brown disperse dyes on polyester. The same molecule is known in agriculture as the fungicide dicloran.

Identification

Use these details when you match 2,6-Dichloro-4-Nitroaniline against your own purchase specification.

Product name: 2,6-Dichloro-4-Nitroaniline
Chemical name: 2,6-Dichloro-4-nitroaniline (2,6-Dichloro-4-nitrobenzenamine)
CAS number: 99-30-9
EC / EINECS: 202-746-4
Molecular formula: C₆H₄Cl₂N₂O₂
Molecular weight: 207.01 g/mol
Product family: Dye and pigment intermediates
Common end use: Disperse dyes for polyester, agrochemical and fine-chemical synthesis

Physical and chemical behaviour

The points that decide how the material handles on your plant and in your reactions.

Appearance: Yellow to golden-yellow crystalline powder.
Melting point: 190–194 °C. Under-chlorinated material (the mono-chloro stage) lowers and broadens the range.
Solubility: Practically insoluble in water (a few mg per litre). Soluble in acetone, dioxane and chlorinated solvents; sparingly soluble in cold ethanol.
Reactivity: The amino group is a very weak base because of the two ortho chlorines and the para nitro group, so diazotisation is done in strong acid, typically with nitrosylsulfuric acid in sulfuric acid or acetic/propionic acid. The diazonium salt is highly electrophilic and couples readily. The nitro group can be reduced to give 2,6-dichloro-1,4-phenylenediamine.
Stability: Stable under normal storage conditions. Keep dry, away from light, heat and incompatible materials.
Incompatibilities: Strong oxidising agents, strong reducing agents and strong bases. Thermal decomposition releases nitrogen oxides and hydrogen chloride.

Typical specification

Every lot is tested in-house against its specification before dispatch, and the results travel with the shipment. If you work to a tighter window on any line below, send it to us and we will confirm whether we can supply to it.

2,6-Dichloro-4-Nitroaniline — parameters tested on each lot. Figures are indicative; the controlling numbers are in the current specification sheet and the batch test report.
Parameter	Indicative value	Why it matters to you
Appearance	Yellow crystalline powder	A consistent colour and free-flowing form show the batch has not picked up oxidation products or moisture.
Assay (purity)	98.0% minby HPLC	Sets the diazo equivalent. A lower assay means more nitrite demand per kilo and weaker dye strength.
Melting point	190–194 °C	A sharp range confirms chlorination went to completion. A low or broad range points to mono-chloro or unchlorinated amine.
2-Chloro-4-nitroaniline	1.0% maxmono-chloro intermediate	Under-chlorinated material also diazotises and couples, adding a redder by-product dye that pulls the shade.
4-Nitroaniline	0.5% maxunreacted starting material	Couples to a brighter orange of its own and moves the batch off standard.
Moisture	0.5% max	Water dilutes nitrosylsulfuric acid and upsets diazotisation stoichiometry.
Ash content	0.1% max	Inorganic salts from the chlorination step leave insoluble residue in the diazo solution.
Acid-insoluble matter	Controlledin sulfuric acid	Insolubles in the diazo solution end up as specks in the press cake and the finished dispersion.

Working to a dye-house specification? Send us your purchase specification, including assay, melting range, mono-chloro and 4-nitroaniline limits and moisture, through the contact page. We will confirm what we can supply, and send a sample with its test data so you can diazotise it beside your current material.

Where 2,6-Dichloro-4-Nitroaniline sits on the synthesis route

DCPNA is made by chlorinating para-nitroaniline, which is itself made from chlorobenzene by nitration and ammonolysis. It sits one chlorine further along the route than 2-chloro-4-nitroaniline, and one step before the diazo bath.

Chlorobenzene

The feedstock. Nitration with mixed acid (HNO₃/H₂SO₄) gives a mixture of chloronitrobenzenes, from which 4-nitrochlorobenzene is separated.
Para Nitroaniline

Ammonolysis of 4-nitrochlorobenzene replaces the activated chlorine with an amino group to give para-nitroaniline.
2-Chloro-4-nitroaniline

Chlorination (chlorine, hypochlorite, or hydrochloric acid with hydrogen peroxide) first puts one chlorine ortho to the amine, giving 2-chloro-4-nitroaniline as the intermediate stage.
2,6-Dichloro-4-nitroaniline

Continued chlorination places the second chlorine at position 6. The product is filtered, washed and dried — the isolated intermediate you buy.
This product
Disperse dyes

Diazotised in nitrosylsulfuric acid and coupled onto N-alkyl-N-cyanoethylanilines or N,N-bis(hydroxyethyl)anilines to give orange and brown disperse dyes. Reduction of the nitro group gives the diamine.

Key derivatives of 2,6-Dichloro-4-Nitroaniline

DCPNA reaches most of its customers through the diazo bath. Each derivative uses either the diazonium salt of the amine or, less often, reduction of the nitro group to a second amine.

Disperse Orange 37/76

With N-ethyl-N-cyanoethylaniline

A reddish-orange monoazo disperse dye for polyester, also used to colour plastics. Both colour index numbers describe the same structure, the best-known dye made from DCPNA.

Class: Monoazo disperse
Coupler: N-Ethyl-N-cyanoethylaniline
Use: Polyester, plastics

Disperse Orange 30

With N-cyanoethyl-N-acetoxyethylaniline

A yellowish-brown to orange disperse dye with good sublimation fastness, widely used in polyester dyeing and printing and as the orange component of brown and black blends.

Class: Monoazo disperse
C.I. No.: 11119
Use: Polyester, blends

Disperse Brown 1

With a bis(hydroxyethyl)aniline coupler

A brown monoazo disperse dye for polyester and acetate. DCPNA is its diazo component, coupled onto a chlorinated N,N-bis(2-hydroxyethyl)aniline.

Class: Monoazo disperse
Route: Diazotise and couple
Use: Polyester, acetate

2,6-Dichloro-p-phenylenediamine

Reduction product

Reducing the nitro group gives the diamine, a building block for heterocycle, specialty monomer and fine-chemical synthesis.

CAS No.: 609-20-1
Route: Nitro reduction
Use: Fine chemicals

Need a related nitroaniline? Para Nitroaniline is the starting material, Ortho Chloro Para Nitro Aniline is the mono-chlorinated stage, and 6-Chloro-2,4-Dinitroaniline is the diazo component for the blue and navy end of the same polyester palette. If you run several shades, all of them can come on the same order.

Where the chemistry leads

2,6-Dichloro-4-Nitroaniline is a diazo component first and foremost. Its quality shows up in the shade, strength and cleanliness of every disperse dye made from it.

Disperse dyes for polyester

DCPNA is a workhorse diazo component for the orange to brown section of the polyester range. Dye makers need tight control of the mono-chloro and unchlorinated amines, because each gives its own dye and pulls the shade.

Brown, black and navy blends

Dyes from DCPNA such as Disperse Orange 30 are staple components of brown, black and navy mixtures. A consistent diazo component keeps the orange component on standard, and with it the whole blend.

Agrochemical and fine chemicals

The same molecule is the fungicide dicloran, used against storage rots on fruit and vegetables; its registration status differs from country to country, so check the rules in your market. Its reduction product is a fine-chemical building block.

What buyers check before they switch supplier

Four parameters explain most of the yield, shade and purity complaints when a manufacturer changes its source of 2,6-Dichloro-4-Nitroaniline.

Assay and chlorination profile

Mono-chloro and unchlorinated nitroaniline both diazotise and couple, adding redder or brighter off-shade dyes to the batch and lowering strength.

Melting point range

A sharp 190–194 °C range is the quickest check that chlorination went to completion. A low or broad range signals a mixed product.

Moisture and ash

Water dilutes the nitrosylsulfuric acid; inorganic salts from the chlorination step leave insolubles in the diazo solution.

Particle size and dispersibility

DCPNA is diazotised as a suspension in strong acid. A fine, even particle size dissolves and diazotises faster and more completely.

Tested in-house, documented in full

Consistent downstream chemistry starts with a consistent intermediate. Each lot of 2,6-Dichloro-4-Nitroaniline is checked against its specification before it leaves, and the result goes out with the material so your goods-in team can release it without a second test.

Each lot tested against the product specification before dispatch
Batch test report supplied with every shipment
Safety Data Sheet supplied with the first order and on request
Technical and specification sheets available before you order
Samples sent with their own test data, so a trial compares like with like
Chemists familiar with weak-base diazotisation and disperse dye coupling, available to discuss results

Ask for a specification How we work

What arrives with the material

Enough paperwork for your goods-in and quality teams to release the lot without retesting it.

Batch test report: The tested figures for the lot you have received, set against the specification.
Safety Data Sheet: Classification, protective equipment, storage conditions, first aid and spill response.
Specification sheet: The parameters and limits we supply against, available before you place the order.
Sample test data: Sent with every trial sample, so a comparison against your current material starts from the same numbers.

Packing, storage and handling

2,6-Dichloro-4-Nitroaniline is a stable crystalline solid, but it is acutely toxic. Follow all guidance in the Safety Data Sheet for protective equipment and exposure control.

How it ships

Supplied in moisture-resistant packing, typically HDPE-lined bags or fibre drums
Bulk quantities can be discussed where your process suits larger packs
Every pack carries the product name, lot number and hazard labelling
Pack size can be matched to your batch charge to minimise part-used containers
Shipped with its batch test report and Safety Data Sheet

Storing and handling on site

Store in a cool, dry, well-ventilated and locked area, away from direct sunlight
Keep containers tightly closed between uses to prevent moisture uptake
Avoid generating dust; charge through closed systems or with local exhaust ventilation
Wear the full protective equipment specified in the SDS — the dust is toxic by inhalation and the solid is absorbed through skin
Keep away from food, feed, oxidising agents and strong bases
Prevent release to drains and watercourses; rotate stock so older lots are used first

Read the Safety Data Sheet before first use. 2,6-Dichloro-4-Nitroaniline is classified as acutely toxic if swallowed, in contact with skin or if inhaled, may cause damage to organs through prolonged or repeated exposure, and is toxic to aquatic life with long-lasting effects. The SDS sets out the required PPE, exposure controls, storage conditions, first-aid measures and spill response. If anything on it is unclear, ask our technical team.

How to order 2,6-Dichloro-4-Nitroaniline

Start with a sample, move to scheduled supply. Four steps from first enquiry to a delivery pattern that matches your production plan.

Send your requirement
Product name, grade or specification, quantity, packing and delivery location, through the contact page.
Get the paperwork
We come back with the specification sheet, the Safety Data Sheet and a quote against your quantity and packing.
Run a sample
A sample with its test data, so you can run it through your diazotisation and coupling beside your current material.
Confirm supply
Once the trial clears, we schedule repeat supply to the same specification, lot after lot.

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2,6-Dichloro-4-Nitroaniline: frequently asked questions

What buyers, chemists and plant teams ask us most about this product. For anything else, get in touch.

What is 2,6-Dichloro-4-Nitroaniline?

2,6-Dichloro-4-Nitroaniline (DCPNA, CAS 99-30-9) is a yellow crystalline aromatic amine with an amino group at position 1, chlorine atoms at positions 2 and 6, and a nitro group at position 4 of the benzene ring. It is used mainly as a diazo component for orange and brown disperse dyes.

What is the CAS number and molecular formula?

The CAS number is 99-30-9. The EC (EINECS) number is 202-746-4. The molecular formula is C₆H₄Cl₂N₂O₂ and the molecular weight is 207.01 g/mol.

How is 2,6-Dichloro-4-Nitroaniline manufactured?

It is made by chlorinating para-nitroaniline in aqueous acid, using chlorine gas, sodium hypochlorite, or hydrochloric acid with hydrogen peroxide. The first chlorine gives 2-chloro-4-nitroaniline; the second gives 2,6-dichloro-4-nitroaniline, which is filtered, washed and dried.

Why is DCPNA diazotised in nitrosylsulfuric acid?

The two ortho chlorines and the para nitro group pull electron density away from the amino group, making it a very weak base. It does not dissolve and diazotise well in dilute hydrochloric acid, so it is diazotised in concentrated sulfuric acid or acetic/propionic acid with nitrosylsulfuric acid.

Which dyes are made from 2,6-Dichloro-4-Nitroaniline?

The best-known are Disperse Orange 37/76 (coupled with N-ethyl-N-cyanoethylaniline), Disperse Orange 30 (coupled with N-cyanoethyl-N-acetoxyethylaniline) and Disperse Brown 1. It is also used in many patented yellow-brown and orange disperse dyes for polyester.

What is the relationship between DCPNA and 2-chloro-4-nitroaniline?

2-Chloro-4-nitroaniline is the mono-chlorinated intermediate on the way from para-nitroaniline to DCPNA. Any left in the product diazotises and couples too, so buyers limit it in the specification.

Is it the same compound as the fungicide dicloran?

Yes. Dicloran is the common name for 2,6-dichloro-4-nitroaniline when it is used as an agricultural fungicide. Its approval for crop use differs between countries, so check the regulations that apply to your market and grade.

Is 2,6-Dichloro-4-Nitroaniline soluble in water?

It is practically insoluble in water, at only a few milligrams per litre. It dissolves in acetone, dioxane and chlorinated solvents, and in concentrated sulfuric acid, which is the usual medium for diazotisation.

What does reduction of DCPNA give?

Reducing the nitro group, catalytically or with iron or sodium sulfide, gives 2,6-dichloro-1,4-phenylenediamine (CAS 609-20-1), a building block for heterocyclic and fine-chemical synthesis.

What shades do DCPNA dyes give?

Coupled onto N,N-disubstituted aniline couplers, DCPNA gives yellow-brown to reddish-orange and brown shades on polyester, acetate and nylon. These dyes are also blended with blues and violets to build browns, navies and blacks.

What purity do you supply?

Standard commercial material is supplied at a minimum assay of 98% by HPLC, with the actual figure for your lot on the batch test report. If you work to tighter limits on the mono-chloro or unchlorinated amine, send your specification and we will confirm what we can supply.

What is the melting point, and why does it matter?

The melting point is 190–194 °C. A sharp, narrow range confirms chlorination went to completion. A lower or broader range indicates 2-chloro-4-nitroaniline or 4-nitroaniline in the product, which would give off-shade dyes.

Is 2,6-Dichloro-4-Nitroaniline hazardous?

Yes. It is classified as acutely toxic by ingestion, skin contact and inhalation, may damage organs through repeated exposure, and is toxic to aquatic life. Handle it only with the controls and protective equipment set out in the Safety Data Sheet.

How is it packed and stored?

It ships as a crystalline powder in moisture-resistant packing (HDPE-lined bags or fibre drums), labelled with the product name, lot number and hazard information. Store it locked, cool, dry and well ventilated, away from food, oxidisers and strong bases.

Can I get a sample, and is there a minimum order?

Yes to samples, sent with their test data so a trial compares like with like. Order quantities depend on the packing, so tell us the volume you expect through the contact page and we will confirm what is practical.

Tell us the grade and quantity of 2,6-Dichloro-4-Nitroaniline you need

Send your specification, the quantity and where it ships to, and our technical team will come back with the specification sheet, a quote and a sample plan. If you also buy Para Nitroaniline or 6-Chloro-2,4-Dinitroaniline, put them on the same enquiry.

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