2,4-Dinitroaniline
1-Amino-2,4-dinitrobenzene · CAS 97-02-9
2,4-Dinitroaniline is the diazo component behind Dinitraniline Orange, Pigment Orange 5, and a long list of orange and red disperse dyes for polyester. Chelora Dyes supplies it lot-tested, with batch data and a Safety Data Sheet on every shipment, so the shade you approved at trial is the shade you get on the next order.
Also sold as: 2,4-DNA · 2,4-Dinitraniline · 2,4-Dinitrobenzenamine · 2,4-Dinitrophenylamine · 1-Amino-2,4-dinitrobenzene · Benzenamine, 2,4-dinitro-
- CAS number
- 97-02-9
- Molecular formula
- C6H5N3O4
- Molecular weight
- 183.12 g/mol
- Appearance
- Yellow crystalline powder
Structure of 2,4-Dinitroaniline
Benzenamine, 2,4-dinitro-What 2,4-Dinitroaniline is
A nitro-substituted aromatic amine made by aminating 2,4-dinitrochlorobenzene. Two nitro groups pull electron density away from the ring, which makes the amine very weakly basic, gives the powder its yellow colour, and shifts every azo colour built from it towards deeper orange and red.
Identification
Use these details when you match 2,4-Dinitroaniline against your own purchase specification.
- Product name
- 2,4-Dinitroaniline
- Chemical name
- 1-Amino-2,4-dinitrobenzene
- CAS number
- 97-02-9
- EC / EINECS
- 202-553-5
- UN number
- 1596
- Molecular formula
- C6H5N3O4
- Molecular weight
- 183.12 g/mol
- Product family
- Pigment and dye intermediates (family A)
- Common end use
- Diazo component for Pigment Orange 5 and disperse dyes
Physical and chemical behaviour
The points that decide how the material handles on your plant.
- Appearance
- Yellow crystalline powder or crystals. Commercial lots run from light yellow to amber, and darker material is common without being off-specification.
- Melting point
- Around 176 to 181 °C, depending on grade. A low or broad melting range is the quickest sign of an impure lot.
- Solubility
- Practically insoluble in water, roughly 0.06 g/L at 20 °C. Soluble in acetone, ethyl acetate, acetonitrile and most alcohols, and it dissolves in strong sulfuric acid for diazotisation.
- Reactivity
- The amine is too weakly basic for ordinary nitrite diazotisation. It is diazotised with nitrosylsulfuric acid in concentrated sulfuric acid, or in an acetic and propionic acid mixture, at low temperature.
- Thermal behaviour
- A polynitro aromatic. It can decompose violently at elevated temperature, so heating, drying and milling steps need proper control.
- Incompatibilities
- Strong oxidising agents, reducing agents, strong bases, and any source of confined heat.
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.
| Parameter | Indicative value | Why it matters to you |
|---|---|---|
| Appearance | Yellow crystalline powder | Colour and crystal habit tell you quickly whether a lot matches the one you qualified. |
| Assay (purity) | 98.0% minby GC or HPLC | Sets how much diazo component you actually charge, and therefore yield and colour strength. |
| Melting range | 176–181 °C | The fastest incoming check on identity and purity. A depressed or wide range points to residual isomers or solvent. |
| Moisture | 0.5% max | Water carried into a sulfuric acid diazotisation dilutes the acid and slows the reaction. |
| Isomer content | Controlledreported on the batch report | Other dinitroaniline isomers diazotise and couple to a different shade, which shows up as drift between lots. |
| Chloro compounds | Low, reported | Residual dinitrochlorobenzene from incomplete amination is the impurity most worth watching on this route. |
| Insolubles | Controlled | Insolubles carry through to the pigment as specks and slow the filtration. |
| Particle size | Free-flowing powder | Governs how quickly the material goes into acid solution at the diazotisation stage. |
Working to a specific grade? Send us your purchase specification, including assay, melting range, moisture and any impurity limits, through the contact page. We will confirm what we can supply, and send a sample with its test data so you can run it beside your current material.
Where 2,4-Dinitroaniline sits on the route to colour
It starts life as chlorobenzene and spends its working life as a diazo component. Knowing the steps either side of it explains why assay, melting range and residual chloro compounds are the lines buyers watch.
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Nitration
Chlorobenzene is nitrated twice to give 2,4-dinitrochlorobenzene, with the chlorine sitting between two powerful electron-withdrawing groups.
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Amination
That chlorine is displaced by aqueous ammonia under pressure. Because the ring is so activated, the reaction runs at modest temperature and pressure compared with mono-nitro chlorobenzenes.
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2,4-Dinitroaniline
The isolated intermediate: a yellow, water-insoluble solid, weakly basic, ready to be taken into strong acid when you charge it.
This product -
Diazotisation
Dissolved in sulfuric acid or an acetic and propionic acid mixture and treated with nitrosylsulfuric acid at low temperature, because plain sodium nitrite will not diazotise so weak a base.
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Coupling
The diazo is run into the coupler: beta-naphthol for Pigment Orange 5, or an N,N-dialkylaniline for orange and red disperse dyes.
What 2,4-Dinitroaniline becomes
One diazo component, several colour families. The coupler you run it into decides whether you end up with an insoluble pigment for inks and plastics or a disperse dye for polyester. The swatches below are indicative only; your own shade card is the reference.
Pigment Orange 5
Dinitraniline Orange, the classic bright orange of this chemistry. Strong, economical and widely used wherever full outdoor durability is not the deciding factor.
- C.I. No.
- 12075
- Shade
- Bright orange
- Typical use
- Inks, paints, rubber
Disperse oranges
Monoazo disperse dyes for polyester, applied from aqueous dispersion at high temperature. The dinitro diazo gives depth of shade and good build-up.
- Class
- Monoazo disperse
- Shade
- Orange to scarlet
- Typical use
- Polyester, blends
Disperse reds
Changing the coupler substituents pushes the same diazo towards red and bluish red. Sublimation and light fastness are set here, at the coupling stage.
- Class
- Monoazo disperse
- Shade
- Red to bluish red
- Typical use
- Textile printing, dyeing
Other fine chemicals
The same intermediate is used well outside colour, as a building block in agrochemical and pharmaceutical synthesis, and as a reagent in analytical work.
- Class
- Intermediate
- Role
- Amine building block
- Typical use
- Fine-chemical synthesis
Running more than one weakly basic amine? 2,5-Dichloro-4-nitroaniline and 2,4,5-Trichloroaniline go through the same acid diazotisation route and can come on the same order, along with the Nitrosylsulfuric Acid to diazotise them.
Where the colour ends up
2,4-Dinitroaniline never reaches a finished article. It reaches you as a diazo component, and its quality shows up two steps later in shade, strength and dispersion.
Inks, paints and rubber
Pigment Orange 5 is a standard bright orange for packaging inks, air-drying paints and rubber goods, chosen for tinting strength and price rather than outdoor durability.
Textile disperse dyes
Diazotised and coupled onto aniline-type couplers, it gives monoazo disperse dyes for polyester and its blends, covering orange, scarlet and red on the shade card.
Fine-chemical synthesis
Outside colour, it serves as an activated aromatic amine for agrochemical and pharmaceutical intermediates, and as a reference material in environmental analysis.
What buyers check before they switch supplier
Four parameters explain most of the shade, strength and yield complaints we hear about when a plant changes its source of 2,4-Dinitroaniline.
Assay against your charge
Recipes are built on active content. A two-point drop in assay is a two-point drop in colour strength unless your charge is corrected for it.
Melting range
The single most useful incoming check. A sharp range in the expected window says the lot is what the label claims; a depressed one says it is carrying something else.
Residual chloro compounds
Unreacted dinitrochlorobenzene from the amination step does not diazotise. It dilutes the charge and adds an impurity you then have to wash out of the pigment.
Dissolution behaviour
Coarse or caked material is slow to dissolve in the acid, which stretches the diazotisation hold and can leave undissolved solids at coupling.
Tested in-house, documented in full
Batch-consistent colour does not happen by accident. Each lot of 2,4-Dinitroaniline 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 who work in diazotisation and coupling every day, available to talk through a result
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.
- Transport documentation
- Classification and labelling for a UN 1596 shipment, prepared with the consignment.
Packing, storage and handling
This is a toxic polynitro aromatic, not an ordinary powder. It is routinely handled in pigment and dye plants, but only with closed transfers, proper protective equipment and controlled heating.
How it ships
- Supplied in moisture-resistant packing, typically lined bags or fibre drums
- Classified and labelled for transport as UN 1596
- Every pack carries the product name, lot number and full hazard information
- Pack size can be matched to your reactor charge, so part-used packs do not sit open
- Shipped with its batch test report and Safety Data Sheet
Storing and handling on site
- Store cool, dry and well ventilated, away from heat, ignition sources and direct sunlight
- Keep well apart from oxidising and reducing agents
- Avoid dust: it is toxic by inhalation, in contact with skin and if swallowed
- Use the gloves, coveralls and respiratory protection named in the Safety Data Sheet, and wash thoroughly after handling
- Avoid release to drains and watercourses; it is hazardous to aquatic life
- Rotate stock so older lots are used first
Read the Safety Data Sheet before first use. 2,4-Dinitroaniline is classified as acutely toxic by the oral, dermal and inhalation routes and as hazardous to the aquatic environment. The SDS sets out the protective equipment, storage conditions, first-aid measures and spill response, and it is what your safety team should work from rather than this page. If anything on it is unclear, ask our technical team.
How to order 2,4-Dinitroaniline
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, packing and shipping route.
Run a sample
A sample with its test data, so you can diazotise and couple it beside your current material and compare shade and strength.
Confirm supply
Once the trial clears, we schedule repeat supply to the same specification, lot after lot.
2,4-Dinitroaniline: frequently asked questions
What buyers, chemists and plant teams ask us most about this product. For anything else, get in touch.
What is 2,4-Dinitroaniline?
2,4-Dinitroaniline is an aromatic amine carrying two nitro groups, chemically 1-amino-2,4-dinitrobenzene. It is a dye and pigment intermediate: the amine is diazotised in strong acid and coupled to give Pigment Orange 5 and a range of orange to red disperse dyes.
What is the CAS number and molecular formula?
The CAS number is 97-02-9 and the EC (EINECS) number is 202-553-5. The molecular formula is C6H5N3O4 and the molecular weight is 183.12 g/mol. For transport it falls under UN 1596.
What other names does it go by?
Common synonyms are 2,4-DNA, 2,4-Dinitraniline, 2,4-Dinitrobenzenamine, 2,4-Dinitrophenylamine, 1-Amino-2,4-dinitrobenzene and Benzenamine, 2,4-dinitro-. Enquiries reach us under all of them, so quote whichever name your specification uses.
What is 2,4-Dinitroaniline used for?
Mostly as a diazo component. Coupled onto beta-naphthol it gives Pigment Orange 5, the Dinitraniline Orange used in inks, paints and rubber. Coupled onto aniline-type couplers it gives monoazo disperse dyes for polyester. It is also used as a building block in agrochemical and pharmaceutical synthesis.
Which pigment is made from it?
Pigment Orange 5, C.I. 12075, sold as Dinitraniline Orange. It is produced by diazotising 2,4-dinitroaniline and coupling the diazonium salt into beta-naphthol.
Why can't it be diazotised with sodium nitrite in the normal way?
Because two nitro groups leave the amine far too weakly basic to protonate and react under ordinary conditions. The standard answer is nitrosylsulfuric acid in concentrated sulfuric acid, or in an acetic and propionic acid mixture, at low temperature. We supply Nitrosylsulfuric Acid for exactly this duty.
How is it different from 4-Nitroaniline?
4-Nitroaniline has one nitro group and can be diazotised conventionally, giving lighter orange shades. The second nitro group in 2,4-dinitroaniline deepens the colour, lowers the basicity further and pushes the coupled product towards orange-red. They are not interchangeable in a recipe.
Is it soluble in water?
Practically insoluble, around 0.06 g/L at 20 °C. It dissolves in acetone, ethyl acetate, acetonitrile and most alcohols, and it is taken into solution in strong sulfuric acid or an organic acid mixture for diazotisation.
What is its melting point?
Commercial material melts at roughly 176 to 181 °C. Because the melting range is so sensitive to impurities, it is the quickest incoming check your goods-in laboratory can run on identity and purity.
What purity do you supply?
Standard commercial material is supplied at a minimum assay of 98%, with the actual figure for your lot on the batch test report. If you work to a higher assay or tighter impurity limits, send us the specification and we will confirm what can be supplied against it.
How does its quality affect the finished colour?
Assay sets the effective charge and therefore colour strength. Isomers couple to a different shade. Residual chloro compounds do not diazotise at all and have to be washed out later. Moisture dilutes a sulfuric acid diazotisation. This is why the batch report matters more than a nominal grade name when you compare two suppliers.
Is 2,4-Dinitroaniline hazardous?
Yes. It is classified as acutely toxic by the oral, dermal and inhalation routes, may cause organ damage on repeated exposure, and is hazardous to aquatic life. It can also decompose violently at elevated temperature. Handle it in closed systems with the protective equipment named in the Safety Data Sheet, and treat the SDS as the authority on classification, handling and first aid.
How is it packed, and how should it be stored?
It ships as a powder in moisture-resistant packing, labelled with the product name, lot number and hazard information, and classified for transport as UN 1596. Store it closed in a cool, dry, well-ventilated place away from heat and ignition sources, apart from oxidising and reducing agents, and use older stock first.
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. Sample and order quantities depend on the packing and the shipping route for a classified material, so tell us the volume and destination through the contact page and we will confirm what is practical.
What documentation comes with the shipment?
A batch test report for the lot supplied, a Safety Data Sheet, and the transport classification and labelling documents for the consignment. Specification and technical data sheets are available before you order.
Tell us the grade and quantity of 2,4-Dinitroaniline 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 Nitrosylsulfuric Acid or other weakly basic amines such as 2,5-Dichloro-4-nitroaniline, put them on the same enquiry.