Para Nitrotoluene
A high-purity mononitrotoluene, supplied as 4-nitrotoluene for reduction to p-toluidine and for the sulfonated route into optical brightener chemistry.
What is Para Nitrotoluene?
Para Nitrotoluene, formally 1-methyl-4-nitrobenzene, is a pale yellow crystalline solid with a methyl group at C-1 and a nitro group directly opposite at C-4. It melts a little above 50°C, so larger users normally take it molten and handle it as a liquid.
Two quite different routes run from it. Reduce the nitro group and you have p-toluidine, a diazo component used across azo dye and pigment manufacture. Sulfonate the ring instead and you have 4-nitrotoluene-2-sulfonic acid, which is the first step of the chain that ends in stilbene optical brighteners — the whiteners in detergents, paper and textiles.
At Chelora Dyes, PNT is crystallised and controlled to a high setting point with the ortho and meta isomers held to tight limits, so both routes run at predictable yield without isomeric by-products carrying through.
- Appearance
- Pale yellow flakes
- Odour
- Faint, aromatic
- Solubility
- Organic solvents
- Function
- Nitro intermediate
- Grade
- Technical / molten
Toluene ring with a para nitro substituent
- Molecular formulaC7H7NO2
- Molecular weight137.14 g/mol
- IUPAC name1-Methyl-4-nitrobenzene
- Functional groupsNitro, methyl
- CAS number99-99-0
Technical product information
Standard specification for Chelora Dyes' technical grade Para Nitrotoluene. Custom-grade and molten bulk specifications are available on request.
| Chemical name | Para Nitrotoluene |
|---|---|
| Synonyms | 4-Nitrotoluene, p-Nitrotoluene, PNT, 1-Methyl-4-nitrobenzene |
| CAS number | 99-99-0 |
| Molecular formula | C7H7NO2 |
| Molecular weight | 137.14 g/mol |
| Assay (purity) | ≥ 99.0% |
| Appearance | Pale yellow crystalline flakes; clear yellow liquid when molten |
| Melting range | 51–54°C |
| Setting point | ≥ 51.0°C |
| Boiling point | Approx. 238°C |
| Ortho + meta isomers | ≤ 0.5% |
| Moisture content | ≤ 0.1% |
| Solubility | Practically insoluble in water; soluble in alcohol, ether, acetone and benzene |
| Packaging | 25 kg / 50 kg bags or lined drums; heated ISO tanks for molten supply |
| Shelf life | 24 months in sealed original packaging |
Applications of Para Nitrotoluene
p-Toluidine manufacture
Reduction of the nitro group gives p-toluidine for downstream diazotization and coupling.
Azo dyes and pigments
Feeds the toluidine chemistry behind red and magenta shades in textile and ink applications.
Optical brightener route
Sulfonation gives PNT-OSA, the entry point to the stilbene fluorescent whitening agent chain.
Agrochemical intermediates
Used as a starting material where a para-substituted toluene core is required.
Pharmaceutical intermediates
Applied as a building block in amine and heterocycle synthesis at smaller volumes.
Fine chemical intermediates
Side-chain oxidation gives nitrobenzaldehyde and nitrobenzoic acid derivatives for further synthesis.
Why choose Chelora Dyes
Consistent purity
Assay controlled at ≥99% with setting point and isomer content verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
Bagged flake for batch users, heated bulk for continuous plants.
Technical support
Reduction, sulfonation, and compliance guidance from our chemistry team.
Storage and guidelines
- Store in tightly sealed original packaging in a cool, dry, well-ventilated store.
- Keep below 30°C where possible — flake softens and cakes as it nears its melting range.
- Melt drums whole in a controlled hot box; never apply direct or localised heat.
- Hold molten material at the minimum workable temperature and avoid prolonged heating.
- Segregate from strong oxidising agents, reducing agents and strong bases.
- Contain spillage and keep it out of drains and surface water.
Handling precautions
Para Nitrotoluene is toxic by inhalation, ingestion and skin absorption, and repeated or uncontrolled exposure can cause methaemoglobinaemia.
It is toxic to aquatic organisms, so spillage must be contained rather than washed away.
Control dust when handling flake, use chemically resistant gloves, chemical splash goggles and protective clothing, and provide local exhaust ventilation at every open transfer point. Molten material adds a thermal burn risk.
Refer to the current Safety Data Sheet for exposure limits, spill containment, disposal and first-aid measures before any handling operation.
Frequently asked questions
What is Para Nitrotoluene used for?
It has two principal outlets. Reduction of the nitro group gives p-toluidine for azo dye and pigment manufacture, and sulfonation gives 4-nitrotoluene-2-sulfonic acid, the entry point to the stilbene optical brightener chain. It is also used in agrochemical and fine chemical synthesis.
How is it different from ortho nitrotoluene?
Nitration of toluene gives both isomers together and they are separated by distillation and crystallisation. The para isomer is a solid at room temperature and leads to p-toluidine and the sulfonated brightener route, while the ortho isomer is a liquid and leads to o-toluidine.
Is it supplied solid or molten?
Both. The product melts at around 52°C, so it is supplied as flake or solidified drums for batch users and as heated molten bulk for continuous plants.
Is Para Nitrotoluene soluble in water?
No. It is practically insoluble in water and soluble in alcohol, ether, acetone and benzene.
What purity do you supply?
Standard grade is supplied at a minimum assay of 99%, with a controlled setting point and ortho and meta isomers and moisture held within tight limits. Higher assay grades can be manufactured to order.
What packaging sizes are available?
25 kg and 50 kg bags or lined drums for flake material, and heated ISO tanks or road tankers for molten bulk supply.
How should it be stored, and for how long?
In sealed original packaging in a cool, dry, ventilated store away from heat, ignition sources, strong oxidisers and reducing agents. 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 toxic to aquatic life. Molten material adds a thermal burn risk. Handle in closed systems where possible and review the current Safety Data Sheet before any operation.
Do you provide a Certificate of Analysis?
Yes. Each batch ships with a Certificate of Analysis and Safety Data Sheet covering assay, setting point, isomer content, moisture and appearance.
