Ortho Anisidine
A high-purity methoxylated aromatic amine supplied as a classical colour base for azo dye and organic pigment manufacture.
What is Ortho Anisidine?
Ortho Anisidine — OA, or 2-methoxyaniline — is a yellowish to reddish-brown liquid carrying a methoxy group next to the amino group. It darkens noticeably on exposure to air and light.
The methoxy group is strongly electron-donating, which makes the amine more reactive toward diazotisation and coupling than aniline and shifts the resulting shades. It is one of the classical dye bases, reached from ortho nitrochlorobenzene by methoxylation to 2-nitroanisole and reduction.
At Chelora Chemicals, OA is distilled to a controlled isomer profile and low colour. Because the substance carries a strict carcinogen classification, it is supplied only to industrial users with the containment and health surveillance that classification requires.
- Appearance
- Yellowish to reddish-brown 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
Aniline ring with a methoxy group in the ortho position
- Molecular formulaC7H9NO
- Molecular weight123.15 g/mol
- IUPAC name2-Methoxyaniline
- Functional groupsPrimary aromatic amine, aryl ether
- CAS number90-04-0
Technical product information
Standard specification for Chelora Chemicals' technical and dye grade Ortho Anisidine. Custom-grade and bulk specifications are available on request.
| Chemical name | Ortho Anisidine |
|---|---|
| Synonyms | OA, 2-Methoxyaniline, o-Anisidine, 2-Aminoanisole |
| CAS number | 90-04-0 |
| Molecular formula | C7H9NO |
| Molecular weight | 123.15 g/mol |
| Assay (purity) | ≥ 99.0% |
| Appearance | Yellowish to reddish-brown clear liquid |
| Density (20°C) | 1.088–1.096 g/cm³ |
| Boiling point | 224°C |
| Melting point | 5°C |
| Flash point | 118°C (closed cup) |
| Isomer content | ≤ 0.5% |
| Water content | ≤ 0.3% |
| Packaging | 200 kg drums, 1000 kg IBC |
| Shelf life | 12 months in sealed original packaging |
Applications of Ortho Anisidine
Azo colour bases
Diazotised as a colour base for azo dyes on textiles, leather, and paper.
Organic pigments
A classical diazo component in red and orange pigment manufacture.
Dye intermediates
Feeds the manufacture of dianisidine-type and other methoxylated colour intermediates.
Pharmaceutical intermediates
Provides a methoxylated aniline core for fine chemical synthesis.
Corrosion inhibitors
Applied in amine-based inhibitor and metal treatment chemical manufacture.
Specialty chemicals
Used in the synthesis of methoxy-substituted aromatic derivatives.
Why choose Chelora Chemicals
Every batch of Ortho Anisidine 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, colour, and water verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From 200 kg drums to IBC quantities.
Technical support
Process, handling, and compliance guidance from our chemistry team.
Storage and guidelines
- 01Store in tightly sealed original containers under a dry, inert atmosphere where possible.
- 02Keep in a cool, dry, well-ventilated store away from direct sunlight and heat.
- 03Protect from air and light — anisidines darken rapidly on oxidation.
- 04Segregate from strong oxidising agents, acids, and acid chlorides.
- 05Use compatible containers: lined steel, stainless steel, or HDPE.
- 06Store in a locked or access-controlled area with clear carcinogen warning signage.
Handling precautions
Ortho anisidine is classified as a carcinogen and is suspected of causing genetic defects. It is also toxic by inhalation, ingestion, and skin absorption. It is for industrial use by trained personnel only.
The carcinogen classification means exposure must be reduced to the lowest technically achievable level rather than merely kept below a limit. Closed handling, exposure monitoring, exposure records, and health surveillance may be legally required at your site.
The substance is readily absorbed through intact skin and forms methaemoglobin. Glove selection with verified breakthrough data and prompt decontamination matter as much as ventilation here.
Use closed transfer and local exhaust ventilation for decanting, charging, and heated operations.
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 Ortho Anisidine used for?
It is a classical azo colour base for dye and pigment manufacture, and an intermediate for methoxylated dye intermediates, pharmaceuticals, and corrosion inhibitors.
How is o-anisidine manufactured?
From ortho nitrochlorobenzene: methoxide displaces the activated chlorine to give 2-nitroanisole, which is then reduced to the amine. Both intermediates in that chain are supplied in this range.
What does the methoxy group contribute?
It is strongly electron-donating, which raises the reactivity of the ring toward coupling and shifts the shade of the resulting dye. That combination of reactivity and hue is why the anisidines have held their place in colour chemistry.
Is o-anisidine a carcinogen?
It carries a strict carcinogen classification and is treated as a probable human carcinogen by major health authorities. Exposure must be reduced to the lowest technically achievable level, and health surveillance may be mandatory under your national rules.
Why does the liquid darken so quickly?
Methoxylated anilines oxidise readily in air and light, more so than plain anilines. Nitrogen blanketing and cool, dark storage slow it considerably, though some colour development is normal.
Is it soluble in water?
Only slightly in neutral water. It dissolves readily in alcohols, ether, and dilute mineral acid, and acid dissolution is the usual first step before diazotisation.
What purity do you supply?
Standard technical grade is supplied at a minimum assay of 99% with isomer content at or below 0.5% and water at or below 0.3%. Tighter specifications can be produced to order.
What packaging sizes are available?
200 kg drums and 1000 kg IBCs. Supply is subject to confirmation of the receiving site's handling capability and regulatory position.
Are there regulatory restrictions on azo colourants made from anisidines?
Several jurisdictions restrict azo dyes that can release certain aromatic amines in consumer textiles and leather, and o-anisidine is among the amines commonly listed. Check your finished-article market before committing to a route using this base.
Is OA hazardous?
Yes, and notably so. It is a classified carcinogen, toxic by several routes, readily skin-absorbed, and toxic to aquatic life. Full engineering controls, PPE, and health surveillance apply.
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, density, colour, water content, and appearance.