Para Chloroaniline
A high-purity chlorinated aniline, supplied as 4-chloroaniline for diazotization into azo dyes and pigments and for agrochemical and pharmaceutical intermediate manufacture.
What is Para Chloroaniline?
Para Chloroaniline, formally 4-chloroaniline, is a white to pale amber crystalline solid with an amino group at C-1 and a chlorine directly opposite at C-4. It melts at around 70°C, so larger users normally take it molten and handle it as a liquid.
The chlorine does two jobs. It withdraws electron density from the ring, which makes the diazonium salt formed from the amine noticeably more stable and easier to hold through a coupling campaign; and it stays in the finished molecule, where it lowers solubility and raises lightfastness in the coupled pigment or dye.
At Chelora Dyes, PCA is crystallised and controlled to a high setting point with the ortho isomer held to a tight limit, so diazotization runs to a clean end point and no isomeric by-product carries an off-shade into the coupling stage.
- Appearance
- White to pale amber
- Odour
- Faint, amine-like
- Solubility
- Alcohol, dilute acid
- Function
- Diazo component
- Grade
- Technical / molten
Aniline ring with a para chlorine substituent
- Molecular formulaC6H6ClN
- Molecular weight127.57 g/mol
- IUPAC name4-Chloroaniline
- Functional groupsPrimary aromatic amine, aryl chloride
- CAS number106-47-8
Technical product information
Standard specification for Chelora Dyes' technical grade Para Chloroaniline. Custom-grade and molten bulk specifications are available on request.
| Chemical name | Para Chloroaniline |
|---|---|
| Synonyms | 4-Chloroaniline, p-Chloroaniline, PCA, 4-Aminochlorobenzene |
| CAS number | 106-47-8 |
| Molecular formula | C6H6ClN |
| Molecular weight | 127.57 g/mol |
| Assay (purity) | ≥ 99.5% |
| Appearance | White to pale amber crystalline flakes; clear when molten |
| Melting range | 68–72°C |
| Setting point | ≥ 68°C |
| Boiling point | Approx. 232°C |
| Ortho isomer | ≤ 0.3% |
| Moisture content | ≤ 0.2% |
| Solubility | Slightly soluble in water; soluble in alcohol, ether and dilute acid |
| Packaging | 25 kg / 50 kg lined drums or bags; heated ISO tanks for molten supply |
| Shelf life | 24 months in sealed original packaging |
Applications of Para Chloroaniline
Azo pigments
Diazotized and coupled to build orange and red pigments with improved lightfastness for inks and coatings.
Azo and azoic dyes
Serves as a diazo component across textile dye chemistry where wet fastness matters.
Pigment intermediates
Feeds intermediates used in masterbatch, plastics colouration and printing ink formulation.
Agrochemical intermediates
A core amine in herbicide, insecticide and other crop protection syntheses.
Pharmaceutical intermediates
Used as a chlorinated aniline building block in antiseptic and active ingredient manufacture.
Rubber and specialty chemicals
Applied in accelerator, antioxidant and other specialty chemical routes in smaller volumes.
Why choose Chelora Dyes
Consistent purity
Assay controlled at ≥99.5% with setting point and isomer content verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
Drummed flake for batch users, heated bulk for continuous plants.
Technical support
Diazotization, molten handling, and compliance guidance from our chemistry team.
Storage and guidelines
- Store in tightly sealed original packaging in a cool, dry, well-ventilated store.
- Keep in the dark and away from heat and ignition sources.
- 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 oxidising agents, acids and acid chlorides.
- Contain all spillage — the product is very toxic to aquatic life and must not reach drains.
Handling precautions
Para Chloroaniline is toxic by inhalation, ingestion and skin absorption, and repeated or uncontrolled exposure can cause methaemoglobinaemia.
It also carries a carcinogen classification in several jurisdictions, so exposure should be reduced as far as reasonably practicable and closed systems used wherever possible.
Control dust at weighing and charging, 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 Chloroaniline used for?
It is diazotized as a diazo component for azo dyes and pigments, where the chlorine improves lightfastness and lowers solubility in the finished colourant. It is also a widely used building block in agrochemical, pharmaceutical and rubber chemical manufacture.
How is it different from ortho chloroaniline?
The two isomers differ in where the chlorine sits relative to the amine. In the para isomer they are opposite, which gives a higher melting solid and a more stable diazonium salt, while the ortho isomer is a liquid and is used where different shade and reactivity are wanted.
Is it supplied solid or molten?
Both. The product melts at around 70°C, so it is supplied as flake or solidified drums for batch users and as heated molten bulk for continuous plants.
Is Para Chloroaniline soluble in water?
Only slightly. It dissolves sparingly in water but freely in alcohol, ether and dilute mineral acid, and the acid solution is the normal starting point for diazotization.
Why has the material darkened?
Aromatic amines oxidise slowly on contact with air and light, and the oxidation products are strongly coloured. A shift from white towards pale amber is normal and does not by itself indicate loss of assay. Keep drums sealed, cool and dark.
What purity do you supply?
Standard grade is supplied at a minimum assay of 99.5%, with the ortho isomer and moisture held to tight limits. Higher assay grades can be manufactured to order.
What packaging sizes are available?
25 kg and 50 kg lined drums or bags for flake material, and heated ISO tanks for molten bulk supply.
How should it be stored, and for how long?
In sealed original packaging in a cool, dry, dark and ventilated store away from heat, oxidising agents and acids. 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, carries a carcinogen classification in several jurisdictions and is very toxic to aquatic life. Handle in closed systems where possible and review the current Safety Data Sheet before any operation.
