5-Chloro-2-methylaniline
A high-purity chlorinated toluidine supplied as a classical azo colour base for dye and pigment manufacture and as a pharmaceutical intermediate.
What is 5-Chloro-2-methylaniline?
5-Chloro-2-methylaniline — long known in the colour trade as Fast Red KB Base — is a low-melting solid that may arrive as crystals, a solidified melt, or a clear yellow to light brown liquid depending on temperature.
It is one of the classical azoic diazo components. Diazotised and coupled on the fibre or in the pigment reactor, it gives the strong red shades that gave it its trade name, and it remains in use where that specific shade and fastness profile is required.
At Chelora Chemicals, it is refined with isomer content and melting range held to specification. Because the material is classified as a suspected carcinogen, it is supplied only to industrial users with the containment and health surveillance the classification requires.
- Appearance
- White to light brown crystals or clear yellow liquid
- Odour
- Characteristic amine odour
- Solubility
- Slightly soluble in water; soluble in alcohol, ether, dilute acid
- Function
- Azo colour base / intermediate
- Grade
- Technical / dye
Formula diagram
Toluidine ring with chlorine at the 5-position
- Molecular formulaC7H8ClN
- Molecular weight141.60 g/mol
- IUPAC name5-Chloro-2-methylaniline
- Functional groupsPrimary aromatic amine, aryl chloride, alkyl
- CAS number95-79-4
Technical product information
Standard specification for Chelora Chemicals' technical and dye grade 5-Chloro-2-methylaniline. Custom-grade and bulk specifications are available on request.
| Chemical name | 5-Chloro-2-methylaniline |
|---|---|
| Synonyms | Fast Red KB Base, 5-Chloro-o-toluidine, 2-Amino-4-chlorotoluene, Azoic Diazo Component 32 |
| CAS number | 95-79-4 |
| Molecular formula | C7H8ClN |
| Molecular weight | 141.60 g/mol |
| Assay (purity) | ≥ 99.0% |
| Appearance | White to light brown crystals or clear yellow liquid |
| Melting point | 22–28°C |
| Boiling point | 237°C |
| Density (20°C) | 1.17–1.18 g/cm³ |
| Flash point | 160°C (closed cup) |
| Isomer content | ≤ 0.5% |
| Moisture | ≤ 0.3% |
| Packaging | 25 kg drums, 200 kg drums |
| Shelf life | 24 months from date of manufacture |
Applications of 5-Chloro-2-methylaniline
Azoic dyeing
The classical Fast Red KB colour base, diazotised and coupled to produce red shades on textiles.
Organic pigments
Used as a diazo component in red and orange pigment manufacture for inks and coatings.
Dye intermediates
Feeds azo dye synthesis where a chlorinated toluidine base is required.
Pharmaceutical intermediates
Applied as a building block in the synthesis of biologically active compounds.
Agrochemical intermediates
Used in crop-protection routes built on substituted toluidine cores.
Analytical standards
Supplied as a reference material for aromatic amine testing.
Why choose Chelora Chemicals
Every batch of 5-Chloro-2-methylaniline 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 to 200 kg drums, with samples for shade trials.
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.
- 02Expect the product to soften or liquefy above about 25°C — check drums before opening.
- 03Protect from air and light; the material darkens on oxidation.
- 04Keep under nitrogen where practical and re-seal opened packaging promptly.
- 05Segregate from strong oxidising agents, acids, and acid chlorides.
- 06Store in a locked or access-controlled area away from food, feed, and drinking water.
Handling precautions
This product is harmful if swallowed or in contact with skin, causes serious eye irritation, and is classified as a suspected carcinogen. It is for industrial use by trained personnel only.
Aromatic amines of this class are readily absorbed through intact skin and cause methaemoglobin formation. Chemical-resistant gloves, coveralls, and eye protection are required, and contaminated clothing must be removed immediately.
The carcinogen classification means exposure should be reduced to the lowest practicable level rather than merely kept below a limit. Health surveillance may be required under your national regulations.
Because the melting point is near ambient, warm-weather storage can produce liquid material in a drum expected to hold solid. Check before opening and avoid skin contact with the liquid phase.
The product is 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, health surveillance, spill response, and first-aid measures before use.
Frequently asked questions
What is 5-Chloro-2-methylaniline used for?
It is a classical azo colour base, known in the trade as Fast Red KB Base, used in azoic dyeing and red pigment manufacture. It also serves as a pharmaceutical and agrochemical intermediate.
What does 'Fast Red KB Base' mean?
It is the historical colour-trade name for this diazo component, also catalogued as Azoic Diazo Component 32 and C.I. 37090. The name refers to the shade it produces rather than to a different chemical.
Is this the same as 3-chloro-o-toluidine?
No. Both are C7H8ClN with a weight of 141.60, but the chlorine positions differ. This is the 5-chloro isomer, a low-melting solid; 3COT is the 3-chloro isomer and a liquid. They give different shades.
Is it a solid or a liquid?
It depends on the temperature. The melting range is roughly 22 to 28°C, so it may be supplied as crystals, a solidified melt, or a clear yellow liquid. All are the same material on specification.
Is it classified as a carcinogen?
It carries a suspected carcinogen classification, and some authorities treat it more strictly than that. Exposure must be reduced to the lowest practicable level, and health surveillance may be required under your national rules. Confirm the requirements that apply to your site.
Is it soluble in water?
Only slightly in neutral water. It dissolves readily in alcohols, ether, and dilute mineral acid, and acid dissolution precedes diazotisation.
Why does the material darken during storage?
Aromatic amines oxidise on contact with air and light. Colour development is normal and usually does not affect assay, but sealed, cool, dark storage preserves appearance for shade-critical work.
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 0.3%. Tighter specifications can be produced to order.
What packaging sizes are available?
25 kg and 200 kg drums, with samples available for shade and coupling trials. Supply is subject to confirmation of the receiving site's handling capability.
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.