Para Nitroaniline
A high-purity nitroaniline, supplied as 4-nitroaniline for diazotization into the para red pigment range and for reduction to p-phenylenediamine.
What is Para Nitroaniline?
Para Nitroaniline is a bright yellow crystalline powder with an amino group at C-1 and a nitro group directly opposite at C-4. It is one of the most recognisable intermediates on a dye plant, both for its colour and for how widely it is used.
The nitro group is what gives it its character. Sitting para to the amine it pulls electron density off the ring, which makes the diazonium salt formed at the amine unusually stable and easy to work with, and pushes the coupled shade to the strong blue-red that the para red pigment family is named for. A second, quite different outlet is reduction of that same nitro group to give p-phenylenediamine.
At Chelora Dyes, PNA is crystallised and dried to a controlled melting range and low moisture, so diazotization runs to a clean end point and the pigment strikes at a reproducible shade batch to batch.
- Appearance
- Bright yellow powder
- Odour
- Faint, characteristic
- Solubility
- Alcohol, acetone
- Function
- Diazo component
- Grade
- Technical / pigment
Aniline ring with a para nitro substituent
- Molecular formulaC6H6N2O2
- Molecular weight138.12 g/mol
- IUPAC name4-Nitroaniline
- Functional groupsPrimary aromatic amine, nitro
- CAS number100-01-6
Technical product information
Standard specification for Chelora Dyes' technical grade Para Nitroaniline. Custom-grade and bulk specifications are available on request.
| Chemical name | Para Nitroaniline |
|---|---|
| Synonyms | 4-Nitroaniline, p-Nitroaniline, PNA, 4-Nitrobenzenamine |
| CAS number | 100-01-6 |
| Molecular formula | C6H6N2O2 |
| Molecular weight | 138.12 g/mol |
| Assay (purity) | ≥ 99.5% |
| Appearance | Bright yellow crystalline powder |
| Melting range | 146–149°C |
| Boiling point | Approx. 332°C |
| Moisture content | ≤ 0.5% |
| Ash content | ≤ 0.1% |
| Insoluble matter | ≤ 0.2% |
| Solubility | Slightly soluble in water; soluble in alcohol, acetone and ethyl acetate |
| Packaging | 25 kg / 50 kg bags or fibre drums, 500 kg jumbo bags |
| Shelf life | 24 months in sealed original packaging |
Applications of Para Nitroaniline
Para red pigments
Diazotized and coupled onto beta-naphthol to build the classic blue-red pigment range for inks and coatings.
Azoic and azo dyes
Serves as a diazo component in azoic dyeing and across textile azo dye chemistry.
p-Phenylenediamine route
Reduction of the nitro group gives PPD for antioxidant, rubber chemical and dye manufacture.
Antioxidants and inhibitors
Feeds antioxidant and corrosion inhibitor chemistry through its reduced and derivatised forms.
Agrochemical and pharma
Used as a nitroaniline building block across crop protection and active ingredient synthesis.
Analytical reagents
Applied as a reference and diazotisation reagent in laboratory and quality-control methods.
Why choose Chelora Dyes
Consistent purity
Assay controlled at ≥99.5% with melting range and shade verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From 25 kg bags to jumbo-bag bulk quantities.
Technical support
Diazotization, reduction, and compliance guidance from our chemistry team.
Storage and guidelines
- Store in tightly sealed original packaging in a cool, dry, well-ventilated store.
- Keep well away from heat sources, direct sunlight and ignition sources.
- Segregate from strong oxidising agents, reducing agents and strong bases.
- Protect from moisture pickup — the powder can cake if exposed to humid air.
- Re-seal bags promptly after use to preserve moisture and assay specification.
- Contain spillage and keep it out of drains and surface water.
Handling precautions
Para Nitroaniline is toxic by inhalation, ingestion and skin absorption, and repeated or uncontrolled exposure can cause methaemoglobinaemia. It is also very toxic to aquatic life.
It is a combustible solid that decomposes exothermically if strongly heated, so bulk material must be kept away from heat sources and from incompatible materials, and never heated in a confined or unventilated container.
Control dust at weighing, charging and any bulk handling point. Use chemically resistant gloves, chemical splash goggles and protective clothing, with local exhaust ventilation where dust may be generated.
Refer to the full Safety Data Sheet for exposure limits, reactivity data, spill containment, disposal and first-aid measures before use.
Frequently asked questions
What is Para Nitroaniline used for?
It has two main outlets. Diazotized and coupled with beta-naphthol it gives the para red pigment range used in printing inks, coatings and plastics. Reduced, it gives p-phenylenediamine, which feeds antioxidant, rubber chemical and dye manufacture.
Why is its diazonium salt so stable?
The nitro group sits directly opposite the amine and withdraws electron density from the ring, which stabilises the diazonium salt formed at the amine. That stability is what allows the salt to be held and coupled reliably, and it also shifts the coupled shade to a strong blue-red.
How does it differ from ortho nitroaniline?
Both are nitroanilines, but the para isomer has the nitro group opposite the amine rather than adjacent. That gives a higher melting solid, a more stable diazonium salt and a bluer coupled shade, while the ortho isomer is used where different shade and reactivity are required.
Is Para Nitroaniline soluble in water?
Only slightly. It dissolves sparingly in water and freely in alcohol, acetone and ethyl acetate, and it is taken into solution in dilute mineral acid for diazotization.
What purity do you supply?
Standard grade is supplied at a minimum assay of 99.5%, with a controlled melting range and moisture and ash held within tight limits. Higher assay grades can be manufactured to order for shade-sensitive pigment work.
What packaging sizes are available?
25 kg and 50 kg multiwall paper or HDPE-lined bags and fibre drums, with bulk supply available in 500 kg jumbo bags.
How should it be stored, and for how long?
In sealed original packaging in a cool, dry, ventilated store, well away from heat sources and from strong oxidisers, reducing agents and strong bases. Shelf life is 24 months from manufacture when storage conditions are maintained.
Is it hazardous to handle?
Yes. It is toxic by inhalation, ingestion and skin absorption, can cause methaemoglobinaemia and is very toxic to aquatic life. It is also a combustible solid that decomposes exothermically if strongly heated, so it must be kept away from heat and incompatible materials. Review the current Safety Data Sheet before any handling operation.
Do you provide a Certificate of Analysis?
Yes. Each batch ships with a Certificate of Analysis and Safety Data Sheet covering assay, melting range, moisture, ash and appearance.
