Para Nitro Aniline
A high-purity nitroaniline supplied as a classical azo colour base for dye and pigment manufacture and as the precursor to p-phenylenediamine.
What is Para Nitro Aniline?
Para Nitro Aniline — PNA, or 4-nitroaniline — is a bright yellow crystalline powder with an amino group and a nitro group at opposite ends of the ring. It is produced by aminating para nitrochlorobenzene.
The two groups sit in direct electronic opposition across the ring, one pushing electron density in and the other pulling it out. That interaction gives the compound its intense colour and, more usefully, makes it one of the most reliable diazo components in azo chemistry.
At Chelora Chemicals, PNA is crystallised and refined with isomer content, melting range, and moisture held to specification, giving dye and pigment manufacturers consistent diazotisation and shade reproducibility.
- Appearance
- Bright yellow crystalline powder
- Odour
- Faint amine odour
- Solubility
- Slightly soluble in water; soluble in alcohol, acetone, dilute acid
- Function
- Azo colour base / intermediate
- Grade
- Technical / dye
Formula diagram
Amino and nitro groups in direct opposition across the ring
- Molecular formulaC6H6N2O2
- Molecular weight138.13 g/mol
- IUPAC name4-Nitroaniline
- Functional groupsPrimary aromatic amine, nitro
- CAS number100-01-6
Technical product information
Standard specification for Chelora Chemicals' technical and dye grade Para Nitro Aniline. Custom-grade and bulk specifications are available on request.
| Chemical name | Para Nitro Aniline |
|---|---|
| Synonyms | PNA, 4-Nitroaniline, p-Nitroaniline, Fast Red GG Base |
| CAS number | 100-01-6 |
| Molecular formula | C6H6N2O2 |
| Molecular weight | 138.13 g/mol |
| Assay (purity) | ≥ 99.0% |
| Appearance | Bright yellow crystalline powder |
| Melting point | 146–149°C |
| Boiling point | approx. 332°C |
| Flash point | > 190°C (closed cup) |
| Isomer content | ≤ 0.5% |
| Moisture | ≤ 0.5% |
| Packaging | 25 kg bags, 500 kg jumbo bags |
| Shelf life | 24 months from date of manufacture |
Applications of Para Nitro Aniline
Azo colour bases
Diazotised as a colour base for red and orange azo shades on textiles and leather.
Organic pigments
A classical diazo component in red, orange, and yellow pigment manufacture.
p-Phenylenediamine route
Reduced to p-phenylenediamine, used in hair dye, aramid, and antioxidant chemistry.
Antioxidants & rubber chemicals
Feeds the synthesis of amine-based antidegradants for rubber compounds.
Corrosion inhibitors
Applied in the manufacture of amine-based inhibitors and metal treatment chemicals.
Pharmaceutical intermediates
Used where a para-difunctional aromatic core is required in fine chemical synthesis.
Why choose Chelora Chemicals
Every batch of Para Nitro Aniline is manufactured, tested, and documented to a standard that formulators and process chemists can build on with confidence — from first sample to full production volume.
Consistent purity
Assay controlled at ≥99% with isomer content and melting range verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From 25 kg bags to 500 kg jumbo bags and full container loads.
Technical support
Process, handling, and compliance guidance from our chemistry team.
Storage and guidelines
- 01Store in tightly closed original packaging in a cool, dry, well-ventilated store.
- 02Keep away from heat, ignition sources, and direct sunlight.
- 03Segregate from strong oxidising agents, acids, and reducing agents.
- 04Keep bags palletised and dry; avoid dust generation and mechanical damage.
- 05Re-seal opened packaging promptly to prevent moisture pick-up and caking.
- 06Prevent release to drains, surface water, and soil.
Handling precautions
PNA is toxic if swallowed, in contact with skin, or if inhaled, and causes damage to organs through prolonged exposure. It is for industrial use by trained personnel only.
Nitroanilines are readily absorbed through intact skin and cause methaemoglobin formation, reducing the blood's oxygen-carrying capacity. Chemical-resistant gloves, coveralls, eye protection, and respiratory protection are required.
Control dust during bag emptying, sieving, and charging, and use local exhaust ventilation at all transfer points.
The product stains skin and surfaces strongly; treat any yellow discolouration of skin as evidence of contact and wash immediately.
The product is very toxic to aquatic life with long-lasting effects. Contain all spills and dispose of waste through licensed routes.
Refer to the full Safety Data Sheet for exposure limits, medical surveillance, spill response, and first-aid measures before use.
Frequently asked questions
What is Para Nitro Aniline used for?
It is an azo colour base for dye and pigment manufacture, and the precursor to p-phenylenediamine. It also feeds rubber antioxidant and corrosion inhibitor synthesis.
How is PNA manufactured?
By ammonolysis of para nitrochlorobenzene, in which ammonia displaces the chlorine activated by the para nitro group. The isomer purity of the PNCB feed carries through to the finished product.
Why is the powder such an intense yellow?
The electron-donating amine and electron-withdrawing nitro group sit directly opposite each other, and the resulting electronic push-pull across the ring absorbs strongly in the visible region. The colour is intrinsic, not an impurity.
What is the difference between PNA, MNA, and ONA?
They are the para, meta, and ortho isomers of nitroaniline, all C6H6N2O2 with a weight of 138.13. They differ in melting point, colour, and coupling behaviour, and are not interchangeable in dye or downstream synthesis.
What is p-phenylenediamine used for?
It is made by reducing PNA and goes into hair dye formulations, para-aramid fibres, and rubber antidegradants. That route accounts for a substantial share of PNA demand.
Is it soluble in water?
Only slightly. It dissolves in alcohols, acetone, and dilute mineral acid, and acid dissolution is the normal first step before diazotisation.
What purity do you supply?
Standard grade is supplied at a minimum assay of 99% with isomer content at or below 0.5% and moisture at or below 0.5%. Tighter specifications can be produced to order.
What packaging sizes are available?
25 kg bags and 500 kg jumbo bags, with full container loads for bulk users. Samples are available for shade and coupling trials.
Is PNA hazardous?
Yes. It is acutely toxic by several routes, readily absorbed through skin, harmful to organs on repeated exposure, and very toxic to aquatic life. Full engineering controls and PPE are required per the Safety Data Sheet.
Are there regulatory restrictions on azo colourants?
Several jurisdictions restrict azo dyes that can release certain aromatic amines in consumer textiles and leather. Check whether your finished-article market imposes limits before committing to a route using this base.
Do you provide a Certificate of Analysis?
Yes. Every batch is dispatched with a Certificate of Analysis and Safety Data Sheet covering assay, isomer content, melting range, moisture, and appearance.