Para Nitro Chloro Benzene
A high-purity nitroaromatic intermediate supplied in flake and molten form for dyes, pigments, agrochemicals, rubber chemicals, and fine chemical synthesis.
What is Para Nitro Chloro Benzene?
Para Nitro Chloro Benzene — known industrially as PNCB and named 1-chloro-4-nitrobenzene under IUPAC rules — is a pale yellow crystalline solid produced by the nitration of chlorobenzene and separation of the resulting para isomer from the ortho fraction.
The molecule carries two reactive handles on one aromatic ring: a chlorine atom that is strongly activated toward nucleophilic aromatic substitution by the para nitro group, and a nitro group that can be reduced to an amine. That combination makes PNCB one of the most widely used building blocks in nitroaromatic chemistry.
At Chelora Chemicals, PNCB is crystallised and refined to a tightly controlled para-isomer content, with ortho isomer and moisture held to specification on every batch so that downstream reduction, amination, and condensation steps run to predictable yield.
- Appearance
- Pale yellow crystalline flakes
- Odour
- Faint, sweetish almond-like
- Solubility
- Insoluble in water; soluble in alcohol, ether, acetone
- Function
- Chemical intermediate
- Grade
- Technical / sublimed
Formula diagram
Chlorine and a nitro group in para positions on a benzene ring
- Molecular formulaC6H4ClNO2
- Molecular weight157.55 g/mol
- IUPAC name1-Chloro-4-nitrobenzene
- Functional groupsAryl chloride, nitro
- CAS number100-00-5
Technical product information
Standard specification for Chelora Chemicals' technical and sublimed grade Para Nitro Chloro Benzene. Custom-grade and bulk specifications are available on request.
| Chemical name | Para Nitro Chloro Benzene |
|---|---|
| Synonyms | PNCB, 4-Nitrochlorobenzene, p-Chloronitrobenzene |
| CAS number | 100-00-5 |
| Molecular formula | C6H4ClNO2 |
| Molecular weight | 157.55 g/mol |
| Assay (purity) | ≥ 99.5% |
| Ortho isomer | ≤ 0.3% |
| Appearance | Pale yellow crystalline flakes or molten liquid |
| Melting point | 82–84°C |
| Boiling point | 242°C |
| Flash point | 127°C (closed cup) |
| Moisture | ≤ 0.1% |
| Packaging | 25 kg & 50 kg bags, 500 kg jumbo bags, molten tanker |
| Shelf life | 24 months from date of manufacture |
Applications of Para Nitro Chloro Benzene
Dye intermediates
Converted to p-nitroaniline and p-phenylenediamine, the backbone of azo dyes and hair-dye intermediates.
Pigments
Feeds the diazo components used in organic yellow, orange, and red pigment chemistry.
Agrochemicals
Serves as a starting material for herbicide and fungicide actives built on nitroaromatic cores.
Pharmaceutical synthesis
Routes to p-aminophenol and related building blocks used in analgesic and API manufacture.
Rubber chemicals
Intermediate for antioxidants and antidegradants used in tyre and technical rubber compounds.
Specialty chemicals
Used in corrosion inhibitors, optical brighteners, and nitro-substituted phenol derivatives.
Why choose Chelora Chemicals
Every batch of Para Nitro Chloro Benzene 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
Para-isomer assay controlled at ≥99.5% with ortho content verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From 25 kg trial quantities to jumbo bags and molten tanker supply.
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, sparks, open flame, and direct sunlight.
- 03Segregate from strong oxidising agents, strong bases, and reducing agents.
- 04Keep containers off the floor on pallets; protect bags from moisture and mechanical damage.
- 05Molten product should be held under temperature control with dedicated, labelled lines.
- 06Store in a locked or access-controlled area away from food, feed, and drinking water.
Handling precautions
PNCB is toxic by inhalation, ingestion, and skin absorption and is classified as a suspected carcinogen. It is for industrial use by trained personnel only.
Absorbed material can affect the blood by forming methaemoglobin. Chemical-resistant gloves, coveralls, eye protection, and respiratory protection are required for handling dust or vapour.
Avoid dust generation during bag emptying, and use local exhaust ventilation for melting, transfer, and charging operations.
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 Chloro Benzene used for?
PNCB is an intermediate rather than an end product. It is used to make p-nitroaniline, p-phenylenediamine, p-aminophenol, and related compounds, which in turn go into dyes, pigments, agrochemicals, rubber antioxidants, and pharmaceutical building blocks.
What is the difference between PNCB and ONCB?
Both are formed together when chlorobenzene is nitrated. PNCB is the para isomer, a solid melting near 83°C, while ONCB (ortho-nitrochlorobenzene, CAS 88-73-3) is the ortho isomer with a lower melting point. They are separated by crystallisation and lead to different downstream products, so isomer purity is a critical specification.
Is PNCB soluble in water?
No. It is practically insoluble in water but dissolves readily in alcohols, ether, acetone, benzene, and hot organic solvents. This is why reactions using PNCB are normally run in organic media or under phase-transfer conditions.
Why is the chlorine atom in PNCB so reactive?
The nitro group in the para position withdraws electron density from the ring and stabilises the intermediate formed during nucleophilic aromatic substitution. As a result, the chlorine can be displaced by amines, alkoxides, and other nucleophiles under conditions where ordinary aryl chlorides are unreactive.
What purity do you supply?
Standard technical grade is supplied at a minimum assay of 99.5% with ortho isomer at or below 0.3% and moisture at or below 0.1%. Tighter specifications can be produced against a customer specification sheet.
How should PNCB be stored?
In closed original packaging in a cool, dry, ventilated area away from heat sources and oxidising agents. Molten storage requires dedicated heated lines and temperature control. Bags should be protected from moisture and physical damage.
What packaging sizes are available?
PNCB is supplied in 25 kg and 50 kg bags, 500 kg jumbo bags, and as molten product in heated tankers for large-volume users.
Is PNCB hazardous?
Yes. It is classified as acutely toxic by several routes, harmful to the blood on repeated exposure, a suspected carcinogen, and hazardous to aquatic life. It should only be handled by trained personnel with appropriate PPE and engineering controls, following the Safety Data Sheet.
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, moisture, melting range, and appearance.
What documentation is available for export shipments?
COA, SDS, packing list, dangerous goods declaration, and country-of-origin documentation are issued with each consignment, along with REACH and regulatory status information where applicable.