Ortho Nitroanisole
A distilled nitro-aromatic intermediate, supplied as 2-nitroanisole for reduction to o-anisidine and onward use across azo dye and pigment manufacture.
What is Ortho Nitroanisole?
Ortho Nitroanisole, formally 1-methoxy-2-nitrobenzene, is a yellow to reddish-brown liquid built on a benzene ring carrying a methoxy group at C-1 and a nitro group at the adjacent C-2 position. It sets to a crystalline mass just below 10°C, so drums held in a cold store will arrive solid.
That adjacency is what makes the molecule useful. The nitro group is reduced — catalytically or with iron — to give o-anisidine, one of the workhorse amines of azo chemistry, and the methoxy group sitting next to the new amine is what shifts the shade and lifts the fastness of every dye and pigment built from it.
At Chelora Dyes, ONA is distilled to tight isomer and moisture limits so the reduction step downstream runs at predictable yield and the o-anisidine it produces carries no colour bodies into the coupling stage.
- Appearance
- Yellow to reddish liquid
- Odour
- Sweet, aromatic
- Solubility
- Organic solvents
- Function
- Reduction feedstock
- Grade
- Technical / distilled
Anisole ring with an ortho nitro substituent
- Molecular formulaC7H7NO3
- Molecular weight153.14 g/mol
- IUPAC name1-Methoxy-2-nitrobenzene
- Functional groupsNitro, methoxy ether
- CAS number91-23-6
Technical product information
Standard specification for Chelora Dyes' distilled grade Ortho Nitroanisole. Custom-grade and bulk specifications are available on request.
| Chemical name | Ortho Nitroanisole |
|---|---|
| Synonyms | 2-Nitroanisole, o-Nitroanisole, ONA, 1-Methoxy-2-nitrobenzene |
| CAS number | 91-23-6 |
| Molecular formula | C7H7NO3 |
| Molecular weight | 153.14 g/mol |
| Assay (purity) | ≥ 99.0% |
| Appearance | Yellow to reddish-brown liquid; solid below approx. 9°C |
| Melting point | 9–10°C |
| Boiling point | Approx. 277°C |
| Density | Approx. 1.25 g/cm³ at 20°C |
| Para isomer | ≤ 0.5% |
| Moisture content | ≤ 0.3% |
| Solubility | Practically insoluble in water; soluble in alcohol, ether, benzene |
| Packaging | 250 kg lined MS / HDPE drums, ISO tanks |
| Shelf life | 24 months in sealed original packaging |
Applications of Ortho Nitroanisole
o-Anisidine manufacture
The primary outlet: reduction of the nitro group gives o-anisidine for downstream diazotization and coupling.
Azo and azoic dyes
Feeds the amine chemistry behind azoic reds and bordeaux shades used in textile and printing applications.
Organic pigments
Supplies intermediates for pigment ranges used in printing inks, coatings and plastics colouration.
Agrochemical intermediates
Used as a starting material where a methoxy-substituted aniline core is required in crop protection chemistry.
Pharmaceutical intermediates
Applied in smaller volumes as a building block for methoxy-aniline derivatives and heterocycle synthesis.
Laboratory and research use
Supplied in drum quantities for process development, pilot trials and analytical reference work.
Why choose Chelora Dyes
Consistent purity
Assay controlled at ≥99% with isomer and moisture verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From single drums to ISO tank and road tanker quantities.
Technical support
Reduction, handling, and compliance guidance from our chemistry team.
Storage and guidelines
- Store in tightly sealed original drums in a cool, dry, well-ventilated store.
- Keep out of direct sunlight and away from heat and ignition sources.
- Expect solidification below 10°C — warm the whole drum gently and homogenise before use.
- Never apply direct flame or localised heat to a solidified drum.
- Segregate from strong oxidising agents, reducing agents and strong bases.
- Bond and earth containers when transferring, and re-seal drums promptly after use.
Handling precautions
Ortho Nitroanisole is a nitroaromatic liquid that is readily absorbed through intact skin and can cause methaemoglobinaemia following repeated or uncontrolled exposure.
It also carries a carcinogen classification in several jurisdictions. Handle in closed systems wherever possible, and avoid all skin and eye contact.
Use chemically resistant gloves, chemical splash goggles and protective clothing, with local exhaust ventilation at any open transfer or sampling point.
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 Ortho Nitroanisole used for?
It is used mainly as the feedstock for o-anisidine, produced by reduction of the nitro group. The resulting amine is a diazo and coupling component for azo dyes and organic pigments, and the same molecule serves as a building block in agrochemical and fine chemical synthesis.
How does it differ from para nitroanisole?
The two isomers differ only in where the nitro group sits relative to the methoxy group. In the ortho isomer they are adjacent, which gives a liquid product at room temperature and leads to o-anisidine on reduction. The para isomer is a solid and leads to p-anisidine, with different shade and fastness behaviour in the finished dye.
Is Ortho Nitroanisole soluble in water?
No. It is practically insoluble in water but mixes readily with alcohols, ether, benzene and most common organic solvents, so reductions are normally run in an organic or mixed medium.
Why has my drum solidified?
The product freezes just below 10°C, so drums held in a cold store will set to a crystalline mass. This is normal and does not affect quality. Bring the whole drum back to ambient temperature or use a hot box or drum blanket at a controlled low temperature, and homogenise before sampling.
What purity do you supply?
Standard distilled grade is supplied at a minimum assay of 99%, with the para isomer and moisture held within tight limits. Higher assay material can be manufactured to order where downstream colour is sensitive.
What packaging sizes are available?
250 kg lined mild steel or HDPE drums, with bulk supply available in ISO tanks and road tankers.
How should it be stored, and for how long?
In sealed original drums in a cool, dry, ventilated store out of direct sunlight and away from strong oxidisers and reducing agents. Shelf life is 24 months from manufacture when storage conditions are maintained.
Is it hazardous to handle?
Yes. It is a nitroaromatic that is absorbed through the skin, can cause methaemoglobinaemia and carries a carcinogen classification in several jurisdictions. Handle in closed systems with chemically resistant gloves, eye protection and ventilation, and read the current Safety Data Sheet before any operation.
Do you provide a Certificate of Analysis?
Yes. Each batch ships with a Certificate of Analysis and Safety Data Sheet covering assay, isomer content, moisture, appearance and density.
