Ortho Nitroanisole
Ortho Nitroanisole is the methyl ether of 2-nitrophenol, and it exists commercially for one purpose: it reduces to o-anisidine, the methoxy-substituted aniline that sits at the head of a large family of azo dyes and organic pigments. The methoxy group is what gives those colourants their characteristic shade and lightfastness, and it has to be installed before the amine, not after.
This material carries a carcinogen classification. We say so here rather than in the small print. Chelora Chemicals supplies it to pigment and dye manufacturers worldwide, in UN-approved packing, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 91-23-6
- IUPAC name
- 1-Methoxy-2-nitrobenzene
- Molecular formula
- C7H7NO3
- Molecular weight
- 153.14 g/mol
- EC / EINECS
- 202-052-1
- UN Number
- 2730 · Class 6.1
- SMILES
- COc1ccccc1[N+](=O)[O-]
- HS Code
- 2909 30*
* Confirm the exact HS heading with your customs broker — nitrated aromatic ethers can sit under a different subheading from the nitrated hydrocarbons depending on the destination tariff schedule.
What Ortho Nitroanisole is used for
Ortho Nitroanisole is a yellow oily liquid at ordinary temperatures that solidifies just below 10 °C. Chemically it is a protected phenol: the methyl ether blocks the hydroxyl so that the ring can be carried through reduction and diazotisation without the phenol interfering. That protection is the whole point.
Reduced, it gives o-anisidine — 2-methoxyaniline — which is diazotised and coupled into a wide range of azo dyes and organic pigments. The methoxy group ortho to the amine twists the geometry of the resulting azo compound and changes both its shade and its fastness, which is why pigment producers specify this particular substitution rather than plain aniline chemistry. A smaller stream of demand comes from fine chemical synthesis where the same fragment is required.
Why the isomer and the ether both matter
- 2-Nitroanisole (CAS 91-23-6) — this product. Methoxy and nitro adjacent on the ring; reduces to o-anisidine.
- 4-Nitroanisole (CAS 100-17-4) — the para isomer, which reduces to p-anisidine and gives entirely different colour chemistry.
- Para nitrophenol (CAS 100-02-7) — the free phenol rather than the ether, so a quite different reactivity. See that page.
- o-Nitrochlorobenzene — an alternative entry point where the chlorine is displaced by methoxide to reach the same ether.
Isomer content is the number that matters most on this product, because it survives the reduction and reappears as an off-shade in the finished pigment. Always quote the CAS number — see the full intermediate range.
Appearance and handling character
The material ships as a clear yellow liquid, practically insoluble in water and miscible with alcohol, ether and most organic solvents. Two handling facts dominate. It freezes in a cold store, which surprises first-time buyers in winter and is not a quality defect. And it carries a carcinogen classification with a suspected mutagenicity entry alongside it — the safety section below should be read before any handling is planned.
| Parameter | Typical value |
|---|---|
| Appearance | Clear yellow liquid (solid below ~9 °C) |
| Assay (GC) | 99.0% min |
| Para isomer | Reported per batch |
| Residual anisole | Reported per batch |
| Moisture (KF) | 0.2% max |
| Freezing point | ≈ 9 – 10 °C |
Important: the figures above are indicative of commercial grade material and are offered for planning only. The batch certificate of analysis is the governing document. On this product the para isomer figure usually decides whether a lot is usable — it reduces to p-anisidine and carries straight into your diazotisation as an off-shade component.
| Property | Value |
|---|---|
| Physical state | Liquid at ambient; freezes near 10 °C |
| Melting / freezing point | ≈ 9 – 10 °C |
| Boiling point | ≈ 273 – 277 °C @ 760 mmHg |
| Flash point | ≈ 140 °C |
| Relative density | ≈ 1.25 |
| Refractive index | ≈ 1.561 – 1.563 |
| Water solubility | Practically insoluble |
| Organic solubility | Miscible with alcohol, ether, acetone |
Physical constants compiled from public reference data for CAS 91-23-6 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
This is a narrow-purpose intermediate. Almost all of it goes the same way — reduction to o-anisidine — and the interest lies in what happens after that.
o-Anisidine production
Catalytic reduction of the nitro group gives o-anisidine, the methoxy-substituted aniline that is the actual workhorse of this chain. Most buyers of nitroanisole are really buying control over the anisidine they will make from it.
- Catalytic reduction route
- Isomer content carries through
- See our intermediate range
Azo dye synthesis
Diazotised o-anisidine couples into a broad family of azo dyes, where the ortho methoxy group shifts the absorption and improves fastness relative to the unsubstituted aniline.
- Diazo component for azo chemistry
- Shade sensitive to isomer content
- See our dye intermediate range
Organic pigments
The same fragment underpins a number of yellow and red organic pigment structures used in inks, coatings and plastics, where the methoxy group contributes to crystal packing and therefore to opacity and lightfastness.
- Yellow and red pigment chemistry
- Tight isomer limits usually apply
- Colour-critical specification quoted on request
Fine chemical synthesis
A smaller stream of demand comes from fine chemical and specialty routes where the 2-methoxy-substituted aromatic is needed as a defined building block rather than as a colour precursor.
- Custom synthesis quantities available
- End-use declaration required
- Technical desk review of your route
Laboratory & reference use
Small quantities are used as reference standards and in method development for nitroaromatic and anisidine analysis — subject, as always, to the controls a carcinogen classification demands.
- Reference-grade material on request
- Small DG-compliant packs
- Full analytical documentation available
Contract & scheduled supply
Pigment plants run to campaign and a classified carcinogen is not a material anyone wants sitting in inventory longer than necessary. We hold the stock and release it against your production calendar.
- Annual contracts with scheduled call-off
- Less material held at your site
- Second source held in reserve
How we supply Ortho Nitroanisole
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On a classified carcinogen, that independence lets us route your order to a producer whose containment, packing and documentation standards actually match what your site and your regulator require.
We place your order with whichever qualified producer best matches your assay, your isomer limit, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, your campaign switches source rather than stalling.
- Carcinogen classification stated up front. It appears in our first reply, not in a document pack that arrives with the goods, so your EHS team can price the controls into the decision.
- Isomer limit read against your shade. Para content survives reduction and shows up in the finished pigment — we confirm your tolerance before quoting a grade.
- Batch COA shared before dispatch. You approve assay and isomer profile against your own spec while the material is still in our warehouse.
- Winter freezing flagged, not ignored. We tell cold-climate buyers that the product solidifies near 10 °C and advise on gentle reheating before anyone opens a drum and assumes it is off-spec.
- Pre-shipment samples for qualification. New account or new source, your laboratory runs a trial before the full quantity ever moves.
- Export machinery handled in-house. UN 2730 classification, approved packing, labelling, freight booking and customs paperwork are ours to manage.
Packed the way your plant receives it
On a classified carcinogen, fewer container openings is a safety outcome as well as a cost one. Tell us how the material will be charged and we will quote accordingly.
UN-approved drums
MS or HDPE-lined drums, UN-certified for Class 6.1 liquids — the standard commercial format for LCL and smaller movements.
IBC totes
Intermediate bulk containers for full-container loads, reducing packing cost per litre and cutting the number of openings your operators make.
Bulk isotainer
For contracted campaign tonnage, bulk movement offers the lowest cost per kilo and the least handling exposure — the right answer on a carcinogen where volumes allow.
Samples & trial packs
Laboratory and pilot quantities dispatched so your R&D team can qualify the grade first — subject to DG rules for your destination and courier.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with DG documentation filed before the booking is made rather than chased afterwards.
Cold-climate planning
The product freezes near 10 °C. For winter shipments to cold destinations we advise on insulated or heated handling and on safe reheating before discharge.
Handle this as a classified carcinogen
Ortho Nitroanisole carries a carcinogen classification with a suspected germ-cell mutagenicity entry alongside it, and is harmful if swallowed. That combination usually triggers substitution review, exposure monitoring and record-keeping duties at the user's site. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document.
Classified hazards
H350May cause cancer.H341Suspected of causing genetic defects.H302Harmful if swallowed.H373May cause damage to organs through prolonged or repeated exposure.H411Toxic to aquatic life with long lasting effects.
Hazard statements reflect classifications commonly published for CAS 91-23-6. Some suppliers additionally list skin and eye irritation entries, and nitroaromatics as a class are associated with methaemoglobin formation on significant exposure. Always read the SDS issued with your specific batch — and treat the carcinogenicity entry as the one that shapes your controls most.
Spill & emergency orientation
Plan your response before the drum arrives, not after a valve leaks. Sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Contain, do not hose to drain. H411 applies — absorb with inert material and collect into a labelled container for licensed disposal.
- Treat every skin contact as significant. With a carcinogen classification there is no routine splash. Remove contaminated clothing immediately and wash thoroughly.
- Reduction is exothermic. Catalytic reduction of a nitroaromatic releases substantial heat — calorimetry and properly sized relief belong in the process design.
- Record the exposure. Most occupational regimes expect an exposure record and health surveillance where a carcinogen is in use. Set this up before an incident, not after one.
- Have the SDS with the casualty. The treating clinician needs the product identity and CAS number in hand.
Storage
- Cool, dry, well-ventilated and access-controlled store, out of direct sunlight and away from heat and ignition sources.
- Plan for the freezing point. At around 10 °C the product solidifies. A frozen drum is not off-specification, but it does need gentle, controlled warming and mixing before use.
- Keep containers tightly closed on a sealed and bunded floor, segregated from reducing agents and strong oxidisers.
- Restrict access and log it. With a carcinogen classification, controlling who can enter the store is a genuine control measure, not an administrative nicety.
- Shelf life is typically 24 months or more in sealed original packing. Re-assay before use after long storage.
Handling & PPE
- Design exposure out, do not manage it down. Closed transfer and mechanical pumping first, local exhaust ventilation second, PPE last — the standard hierarchy applies with extra force to a carcinogen.
- Skin protection is the priority. Chemical-resistant gloves and coveralls, with contaminated clothing removed, bagged and handled as contaminated waste.
- Respiratory protection where vapour may exceed exposure limits, particularly during drum opening, sampling and transfer, per your own exposure assessment.
- Health surveillance and exposure records. Where the carcinogen classification triggers obligations at your site, your occupational health provider and EHS function own the detail.
- Never discharge to drain or watercourse. Contain and dispose of as regulated chemical waste.
Transport
Nitroanisoles move as regulated cargo under UN 2730, Class 6.1. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made. The applicable packing group is stated on your shipping documents and SDS — ask us for the current DG paperwork when you plan the shipment.
What travels with every consignment
A chemical shipment is only as good as the file that travels with it. Verifying what the source plant sends is precisely the work you are buying from a supplier.
Certificate of Analysis
Batch-specific assay by GC, para isomer and residual anisole content and moisture — checked against your purchase specification before we release the goods.
GHS Safety Data Sheet
Full 16-section SDS in GHS format covering hazards, exposure controls, handling, storage, spill response, toxicology and disposal — issued in the language your destination requires.
Dangerous Goods Declaration
UN 2730, hazard class, packing group and IMDG or IATA declaration prepared and filed before the container is booked, with correctly marked and labelled packaging.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief at the destination.
Third-party inspection
SGS, Intertek or Bureau Veritas sampling and inspection arranged on request before loading, giving you independent verification of what actually ships.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives. Retention samples held against the batch.
Protect the phenol, then reduce the ring
The methyl ether is there so that the oxygen does not interfere later. The routes below are the general industrial pattern, not a process disclosure.
Methylate or substitute
Commercial material is reached either by methylation of o-nitrophenol or by displacing the chlorine of o-nitrochlorobenzene with methoxide.
Separate the isomers
Para isomer and residual anisole are removed by distillation. What is left shows up as the isomer figure on the COA — the number pigment producers read first.
Reduce to the anisidine
Catalytic reduction converts the nitro group to an amine, giving o-anisidine with the methoxy group intact and ortho to it.
Diazotise and couple
The anisidine is diazotised and coupled to build the azo dye or pigment, where the ortho methoxy governs shade, crystal packing and fastness.
Why feed quality carries through the whole route
In colour chemistry, impurities do not disappear — they become a second, unwanted chromophore:
- Para isomer reduces to p-anisidine, diazotises alongside your intended component and couples to a different shade. On a pigment this is visible immediately and expensive to correct.
- Residual anisole has no nitro group to reduce, so it simply passes through the process as dead weight and an effluent burden.
- Moisture affects catalyst life and selectivity in the reduction step.
- Oxidation products from poorly sealed storage darken the feed and carry colour into a product whose whole value is its colour.
That is why we quote against your written isomer limit rather than a generic "technical" grade, and why the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Intermediate | Principal character |
|---|---|
| Ortho nitroanisole CAS 91-23-6 — this product | Methyl ether Route to o-anisidine |
| Para nitrophenol CAS 100-02-7 | Free acidic phenol Route to p-aminophenol |
| Meta nitrochlorobenzene CAS 121-73-3 | Chloro, not methoxy Route to m-chloroaniline |
We supply across the nitro aromatic range — see the full intermediate range. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
The carcinogen classification
Classification as a carcinogen raises the cost of producing, storing and moving this material everywhere along the chain, and has pushed some producers out of it entirely. Fewer plants means less price competition.
- Containment cost sits inside the price
- Some destinations restrict it tightly
- We check destination rules before quoting
Upstream feedstock
Depending on the plant, the route runs back through o-nitrophenol or through chlorobenzene nitration plus methoxide. Methanol, chlorine and nitration economics all feed through within a quarter or so.
- Two routes, two cost structures
- Methanol price moves the ether step
- We flag feedstock-driven moves in the quote
Pigment market cycles
Downstream pigment demand follows coatings, inks and plastics, which follow construction and packaging. Intermediate buying runs a quarter or two ahead of all of it.
- Quote early for campaign tonnage
- Spot buying at peak costs materially more
- Contracted call-off smooths the exposure
Isomer specification
A tight para-isomer ceiling narrows the number of plants that can serve you and adds distillation cost. If your shade can tolerate standard isomer content, say so — it is often the cheapest change available.
- Tighter isomer limits narrow the source list
- Distillation cost is real
- We will tell you when you are over-specifying
Freight & DG surcharges
Class 6.1 cargo carries a hazardous surcharge and space is tighter than for general cargo. Destination and Incoterm move landed cost as much as the ex-works price does.
- Compare on landed cost, not ex-works
- DG space books out ahead of peak season
- We quote FOB, CIF, CFR or DDP as you prefer
Source availability
A plant turnaround, an environmental inspection or a monsoon disruption can take capacity offline at short notice. On a product with a short producer list, single-sourced buyers feel this hardest.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
| If your end use is… | Specify |
|---|---|
| Organic pigment synthesis | Tight para-isomer ceiling; low residual anisole |
| Azo dye synthesis | Isomer limit; colour of reduced product checked |
| Captive reduction to anisidine | Low moisture for catalyst life; consistent assay |
| Fine chemical route | Full GC profile; retention sample held |
| Laboratory / reference | Highest available purity, small DG-compliant pack |
Not sure which column you are in? Describe what you make from it and our technical desk will recommend the grade — including telling you when a cheaper specification would do the job just as well.
Support that goes beyond shipping the drum
What our technical desk will do
- Set the isomer limit with you. It is the number that decides whether a lot works, and the one most often left vague on a purchase order.
- Be straight about the hazard profile. The carcinogen and suspected-mutagen classifications are stated at enquiry stage so your EHS team can price the controls into the decision.
- Advise on cold-climate handling. A frozen drum in January is predictable, and we would rather you plan for it than call us about it.
- Review your specification before it goes into a contract, so you are not locked into a limit that no plant can consistently hit.
Regulatory & compliance notes
- Carcinogen obligations are jurisdiction-specific and substantial. Many regimes impose substitution reviews, exposure monitoring, health surveillance, record retention and restrictions on who may work with the material. Confirm what applies at your site before the first delivery.
- Import controls vary by destination, and a few jurisdictions restrict classified carcinogens more tightly than the general chemical regime. We check before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions — we will supply the identity data you need for that filing.
- Downstream colourant rules may apply to your finished product independently of the intermediate. Your regulatory team should confirm what governs the article you sell.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import and your workplace. What we commit to is accurate product identity data, an honest statement of the hazard classification and complete documentation to work from.
From enquiry to delivered pallet
Send the specification
Product name or CAS 91-23-6, your assay and para-isomer limits, quantity, pack preference and destination port.
Receive a firm quote
Pricing, lead time, packing and Incoterm confirmed in writing within 24 hours — our sourcing desk is staffed around the clock.
Qualify and approve
Sample dispatched if you are qualifying a new source. Batch COA shared for your approval before the material is released.
Ship and track
UN 2730 classification filed, DG freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
Others in the Chelora range
What buyers ask us about Ortho Nitroanisole
Is this material classified as a carcinogen?
Why buy the nitroanisole rather than o-anisidine directly?
Is it a liquid or a solid?
What purity do you normally supply?
What is the minimum order quantity?
How long does delivery take?
How should we store it, and what is the shelf life?
Is this a dangerous good? What paperwork comes with it?
- Batch certificate of analysis
- GHS-format safety data sheet
- Dangerous-goods declaration with UN number, class and packing group
- Commercial invoice, packing list and bill of lading or airway bill
- Certificate of origin and any destination-specific forms
Do you supply to my country?
Do you manufacture this yourself?
Request pricing on Ortho Nitroanisole
Send your required assay, para-isomer ceiling, quantity, pack format and destination port. Our sourcing desk is available 24 hours a day, 7 days a week, and comes back with pricing, lead time and packing options — whether that is a single trial pack or a contracted programme for the year.