Ortho Anisidine
A high-purity methoxy-substituted aniline, supplied as Ortho Anisidine (OA), used as a diazo component across the azo dye, pigment and fine chemical industries.
What is Ortho Anisidine?
Ortho Anisidine, abbreviated OA, is a colourless to pale yellow oily liquid built on a benzene ring carrying a methoxy group ortho to the primary amino group, with a characteristic amine-like odour. It darkens to brown on exposure to air and light.
Its primary industrial role is as a diazo component: the amino group is readily diazotised and coupled to build azo dyes and pigments, making OA a foundational intermediate across a very wide share of the coloured azo chemistry produced worldwide, alongside related anilines used elsewhere in dye and pigment manufacture.
At Chelora Dyes, ortho anisidine is distilled and stabilised to a controlled colour and crystallisation-point specification, so downstream diazotisation and coupling reactions run cleanly and give a consistent, reproducible feedstock batch to batch.
- Appearance
- Pale yellow oily liquid
- Odour
- Amine-like
- Solubility
- Ethanol, ether, acetone, benzene
- Function
- Diazo component
- Grade
- Technical / dye grade
Benzene ring with ortho amino and methoxy groups
- Molecular formulaC7H9NO
- Molecular weight123.15 g/mol
- IUPAC name2-Methoxyaniline
- Functional groupsPrimary amine, methoxy
- CAS number90-04-0
Technical product information
Standard specification for Chelora Dyes' technical grade Ortho Anisidine. Custom-grade and bulk specifications are available on request.
| Chemical name | Ortho Anisidine |
|---|---|
| Synonyms | OA, o-Anisidine, o-Methoxyaniline, 2-Aminoanisole |
| CAS number | 90-04-0 |
| Molecular formula | C7H9NO |
| Molecular weight | 123.15 g/mol |
| Assay (purity) | ≥ 99.0% |
| Appearance | Colourless to pale yellow liquid |
| Boiling point | 224°C |
| Density (20°C) | 1.092 g/mL |
| Crystallisation point | ≥ 6.2°C |
| Colour (APHA) | ≤ 30 |
| Solubility | Slightly soluble in water; miscible with ethanol, ether, acetone and benzene |
| Packaging | 200 kg / 225 kg drums, 1000 L IBC totes, ISO tank / bulk tanker |
| Shelf life | 24 months in sealed original packaging |
Applications of Ortho Anisidine
Azo dye synthesis
Diazotised and coupled to build a wide range of azo dyes used in textiles and leather.
Pigment intermediates
Feeds azo and triphenylmethane pigment routes used across printing inks and coatings.
Corrosion inhibitors
Used as a component in some corrosion-inhibitor formulations.
Fine chemical intermediates
Serves as a starting material for pharmaceutical and fragrance intermediate synthesis.
Fast Base / Fast Salt production
Precursor to diazonium salts used as fast colour bases in the dye trade.
Analytical reagents
Used as a reference reagent in analytical and research-scale organic chemistry.
Why choose Chelora Dyes
Consistent purity
Assay controlled at ≥99% with colour and crystallisation point verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From drums to IBC totes, ISO tanks and bulk tanker.
Technical support
Process, diazotisation, and compliance guidance from our chemistry team.
Storage and guidelines
- Store in tightly sealed original drums, totes or tanks in a dry environment.
- Protect from light and air to limit darkening and oxidation.
- Keep in a cool, dry, well-ventilated area away from direct sunlight and heat sources.
- Segregate from strong oxidising agents, acids and acid chlorides.
- Use compatible containers: steel or lined drums, totes and tanks.
- Re-seal containers promptly after use and follow site procedures for toxic-liquid handling.
Handling precautions
Ortho Anisidine is toxic if swallowed, inhaled or absorbed through the skin, so it should be handled only with appropriate PPE and, where practical, closed-system transfer.
Use chemically resistant gloves, eye and face protection, and adequate ventilation during transfer, charging, and any bulk handling operation.
Keep away from open flame and sources of ignition, and away from strong oxidisers. The substance is also classified as hazardous to aquatic life, so avoid release to drains or watercourses.
Refer to the full Safety Data Sheet for exposure limits, monitoring requirements, spill containment, disposal, and first-aid measures before use.
Frequently asked questions
What is Ortho Anisidine used for?
Ortho Anisidine is chiefly used as a diazo component in the manufacture of azo dyes and pigments, and as a chemical intermediate for a range of downstream fine chemical and pharmaceutical syntheses.
How is Ortho Anisidine produced?
It is typically produced by reduction of ortho-nitroanisole, giving a methoxy-substituted aniline that darkens on standing in air unless stabilised and stored correctly.
Is Ortho Anisidine soluble in water?
It is only slightly soluble in water, but it is miscible with ethanol, diethyl ether, acetone and benzene.
What purity do you supply?
Standard technical grade is supplied at a minimum assay of 99.0%, with crystallisation point and colour held within tight limits.
How is Ortho Anisidine packaged and shipped?
As a liquid, it is supplied in 200 kg / 225 kg net drums, with bulk supply available in 1000 L IBC totes, ISO tank containers or rail/road tanker for large volumes.
How should it be stored, and for how long?
In tightly sealed original containers or tanks, protected from light and air, in a cool, dry, well-ventilated store. Shelf life is 24 months from manufacture when storage conditions are maintained.
Is it hazardous to handle?
Ortho Anisidine is toxic if swallowed, inhaled or absorbed through the skin, and is classified as hazardous to aquatic life. It should be handled only with appropriate PPE and adequate ventilation. Review the Safety Data Sheet before any handling operation.
Do you provide a Certificate of Analysis?
Yes. Each batch ships with a Certificate of Analysis and Safety Data Sheet covering assay, moisture, colour and crystallisation point.
