Meta Nitrochlorobenzene
Meta Nitrochlorobenzene is the isomer you cannot get from the obvious reaction. Nitrating chlorobenzene gives you ortho and para, because chlorine directs that way — the meta isomer barely appears. Commercial m-NCB is made the other way round, by chlorinating nitrobenzene, where the nitro group sends the incoming chlorine to the meta position. Different route, different plants, different economics.
Chelora Chemicals supplies m-NCB to dye and pigment manufacturers, agrochemical producers and fine chemical houses worldwide, in UN-approved packing, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 121-73-3
- IUPAC name
- 1-Chloro-3-nitrobenzene
- Molecular formula
- C6H4ClNO2
- Molecular weight
- 157.55 g/mol
- EC / EINECS
- 204-496-1
- UN Number
- 1578 · Class 6.1
- SMILES
- [O-][N+](=O)c1cccc(Cl)c1
- HS Code
- 2904 99*
* Confirm the exact HS heading with your customs broker — compounds carrying both chloro and nitro substituents can sit under a different subheading from the simple nitroaromatics depending on the destination tariff schedule.
What Meta Nitrochlorobenzene is used for
m-NCB is a pale yellow crystalline solid melting around 45 °C, carrying a chlorine and a nitro group in a meta relationship. That geometry defines both what the molecule is good for and what it is not good for. The nitro group is too far from the chlorine to activate it, so this is not a substrate for easy nucleophilic substitution — but the nitro group itself reduces cleanly, and that is the reaction the whole market is built on.
Reduce m-NCB and you have m-chloroaniline: a primary aromatic amine with a chlorine held firmly in the meta position, ready to diazotise, acylate or condense. From there the chain runs into azo dyes and organic pigments, agrochemical actives built on chlorinated aniline cores, and pharmaceutical and fine chemical intermediates. A smaller stream of demand goes into m-nitrophenol and m-aminophenol chemistry.
Why the isomer decides everything
- Meta nitrochlorobenzene (CAS 121-73-3) — this product. Chlorine meta to nitro; chlorine essentially unactivated; made by chlorinating nitrobenzene.
- Ortho and para nitrochlorobenzene — the two major nitration products, both with activated chlorine, both far more abundant and cheaper.
- 2,4-Dinitrochlorobenzene (CAS 97-00-7) — two activating nitro groups; the chlorine is displaced under mild conditions. See that page.
- Dichloronitrobenzenes — two chlorines and one nitro; used where a dichloroaniline is the target. See 3,4-dichloronitrobenzene.
Nothing on this page transfers to the ortho or para grade. Put the CAS number on your purchase order and we will confirm it before quoting — see the full intermediate range.
Appearance and handling character
The material ships as a pale yellow to yellow crystalline solid or flake, insoluble in water and soluble in alcohol, benzene, ether and other organic solvents. With a melting point in the mid-forties it softens and cakes in a hot warehouse, which matters for drum handling in tropical ports. It is toxic by all three exposure routes, absorbed through intact skin, associated with methaemoglobin formation, and hazardous to the aquatic environment. The safety section below should be read before any handling is planned.
| Parameter | Typical value |
|---|---|
| Appearance | Pale yellow crystalline solid / flake |
| Assay (GC) | 99.0% min |
| Melting range | 44 – 46 °C |
| Ortho / para isomer content | Reported per batch |
| Residual nitrobenzene | Reported per batch |
| Moisture | 0.2% max |
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 isomer content is the number to read first — ortho and para carry straight through reduction into the wrong chloroaniline, and no downstream step will separate them for you cheaply.
| Property | Value |
|---|---|
| Physical state | Solid at ambient; melts just above |
| Melting point | ≈ 44 – 46 °C |
| Boiling point | ≈ 235 – 236 °C @ 760 mmHg |
| Flash point | ≈ 120 – 130 °C |
| Relative density | ≈ 1.30 – 1.35 |
| Water solubility | Practically insoluble |
| Organic solubility | Soluble in alcohol, benzene, ether, acetone |
| Chlorine reactivity | Unactivated — nitro group is meta |
Physical constants compiled from public reference data for CAS 121-73-3 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
Almost every industrial use of m-NCB begins by reducing the nitro group. What differs is what the resulting m-chloroaniline is built into.
m-Chloroaniline production
Catalytic hydrogenation or chemical reduction of the nitro group gives m-chloroaniline, the single largest outlet for this material and the gateway to everything else on this list.
- Catalytic and chemical reduction routes
- Isomer purity carries straight through
- See our intermediate range
Azo dye & pigment chemistry
Diazotised m-chloroaniline is a standard diazo component across azo dye and organic pigment manufacture, where the meta chlorine tunes shade, lightfastness and migration resistance in the finished colourant.
- Azo dye diazo components
- Organic pigment intermediates
- See our dye intermediate range
Agrochemical intermediates
Chlorinated aniline cores are a recurring structural motif in crop protection chemistry, where the meta-substituted variant is specified for its particular biological and physical property profile.
- Urea and amide herbicide chemistry
- Custom synthesis quantities available
- See our agrochemical intermediate range
Pharmaceutical & fine chemicals
The m-chloroaniline fragment appears in a range of pharmaceutical and fine chemical synthesis routes, generally where a halogen is needed at a defined ring position for later coupling or for metabolic stability.
- Tight related-substance limits usually apply
- Full analytical documentation available
- Source locked after your qualification
m-Nitrophenol & m-aminophenol routes
Under forcing conditions the chlorine can still be displaced, giving access to m-nitrophenol and, after reduction, m-aminophenol — a smaller but established outlet for this isomer.
- Forcing hydrolysis conditions required
- Related to para nitrophenol chemistry
- Technical desk review of your step
Contract & scheduled supply
This isomer is campaigned less often than the ortho and para grades, so buying it on the spot market at the wrong moment is genuinely expensive. We hold inventory and release it to your production schedule.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Meta Nitrochlorobenzene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On an isomer made by a minority route, with a short producer list and campaign-based availability, owning no plant is exactly the point — we are not trying to place whatever a captive unit happens to have made.
We place your order with whichever qualified producer best matches your assay, your isomer ceiling, 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.
- Isomer confirmed before we quote. Meta, ortho or para — we settle that in the first reply. The price difference alone makes this worth two minutes.
- Isomer content reported, not averaged. Ortho and para appear as separate figures on the COA, because that is what your reduction step actually carries forward.
- Batch COA shared before dispatch. You approve assay, melting range and isomer profile against your own spec while the material is still in our warehouse.
- Packing suited to a low-melting solid. Caking in a hot container is a real problem on this product, and we plan packing and routing around it rather than discovering it at your gate.
- Hazard status stated up front. Toxic by all routes, skin-absorbed and a methaemoglobin former — we say so at enquiry stage, not in the small print of a document pack.
- Export machinery handled in-house. UN 1578 classification, approved packing, labelling, freight booking and customs paperwork are ours to manage.
Packed the way your plant receives it
With a melting point in the mid-forties, pack format on this product is as much about surviving the container as it is about cost per kilo.
UN-approved drums
Fibre or HDPE drums with inner liner, UN-certified for Class 6.1 solids — the standard commercial format and the easiest to handle without generating dust.
Large drums
Larger UN drums for high-volume users with mechanical handling, cutting cost per kilo and the number of openings your operators make.
Molten movement
Where you charge molten and have heated receipt facilities, molten bulk movement is possible in suitable equipment, subject to the DG position for your destination.
Samples & trial packs
Laboratory and pilot quantities dispatched so your R&D team can qualify the grade first — subject to the dangerous-goods 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.
Campaign despatch
This isomer is campaigned less frequently than ortho and para. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Toxic by every route, and absorbed through skin
Meta Nitrochlorobenzene is toxic if swallowed, in contact with skin and if inhaled, is associated with methaemoglobin formation and blood effects on repeated exposure, and is hazardous to the aquatic environment. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document and should govern your risk assessment, PPE selection, exposure monitoring and emergency planning.
Classified hazards
H301Toxic if swallowed.H311Toxic in contact with skin.H331Toxic if inhaled.H373May cause damage to organs through prolonged or repeated exposure (blood).H411Toxic to aquatic life with long lasting effects.
Hazard statements reflect classifications commonly published for CAS 121-73-3. Some suppliers list additional irritation or organ-toxicity entries, and the aquatic classification is stated as H410 by some sources. Always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the drum arrives, not after one splits on a forklift. The points below are orientation for your emergency planners — sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Collect solid mechanically, avoid raising dust, and place it in a labelled container for licensed disposal. Do not sweep dry if that will generate airborne fines.
- Contain, do not hose to drain. The material is toxic to aquatic life — washing a spill away converts a contained incident into a reportable one.
- Assume skin absorption. Contaminated clothing is a continuing exposure route — remove it immediately and wash the skin thoroughly.
- Watch for delayed signs. Methaemoglobinaemia may present some time after exposure. A casualty who feels fine should still be assessed, and blue discolouration of lips or fingertips is a red flag.
- 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. The melting point is in the mid-forties, so an uncooled warehouse in a hot climate will soften and cake the product.
- Keep containers tightly closed on a sealed and bunded floor. Dust and fines from a damaged drum are the most likely route to an unplanned exposure.
- Segregate from reducing agents, strong alkalis and oxidisers — this is a reactivity control, not a housekeeping preference.
- Restrict access. Given the toxicity classification, limiting who can enter the store is a genuine control measure.
- Shelf life is typically 24 months or more in sealed original packing under these conditions. Re-assay before use after long storage.
Handling & PPE
- Design exposure out, do not manage it down. Closed transfer, contained charging and dust suppression first; local exhaust ventilation second; PPE last.
- Skin protection is the priority. Nitroaromatics of this type pass through intact skin — chemical-resistant gloves and coveralls, not just splash protection.
- Respiratory protection during drum opening, charging and any operation that can generate dust or warm vapour, per your own exposure assessment.
- Health surveillance. Where repeated-exposure blood effects trigger obligations at your site, your occupational health provider and EHS function own the detail.
- Never discharge to drain or watercourse. Contain spills and dispose of them as regulated chemical waste.
Transport
m-NCB moves as regulated cargo under UN 1578 (chloronitrobenzenes), 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, melting range, ortho and para isomer content, residual nitrobenzene and moisture — checked against your 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 1578, 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.
Made by the reverse route — and reduced, not substituted
Two facts explain almost everything about this product: how it has to be made, and which of its two functional groups actually reacts. The routes below are the general industrial pattern, not a process disclosure.
Start from nitrobenzene
The nitro group is a meta director, so chlorinating nitrobenzene puts the chlorine where you want it — the opposite of what nitrating chlorobenzene would give.
Separate the isomers
Minor ortho and para isomers are removed by crystallisation and distillation. How well that is done is the whole quality story on this product.
Reduce the nitro group
Downstream, catalytic hydrogenation or chemical reduction converts the nitro group to an amine, giving m-chloroaniline with the chlorine untouched.
Diazotise or acylate
The primary amine is then diazotised and coupled into an azo chromophore, or acylated and built into an agrochemical or pharmaceutical structure.
Why the chlorine will not simply leave
Buyers moving onto this product from an activated substrate are sometimes surprised that their substitution conditions do nothing. The reason is purely positional. Nucleophilic aromatic substitution needs the electron-withdrawing group ortho or para to the leaving group so it can delocalise the negative charge of the intermediate. A meta nitro group cannot do that, so the chlorine here behaves much like the chlorine on plain chlorobenzene — displaceable only under forcing conditions.
Which impurities matter follows directly from that:
- Ortho and para isomers survive your reduction step intact and arrive as the wrong chloroaniline in your product — the single most consequential impurity on this line.
- Residual nitrobenzene reduces to aniline, which then diazotises and couples alongside your intended component.
- Dichlorinated by-products from over-chlorination carry an extra halogen through the whole chain.
- Melting range is the quick practical read on all of the above — a depressed or broad range tells you something is present that the assay figure alone may not reveal.
That is why the batch COA reports isomer content and melting range alongside assay, and why we share it for approval before dispatch rather than sending it with the invoice.
| Intermediate | Chlorine behaviour |
|---|---|
| Meta nitrochlorobenzene CAS 121-73-3 — this product | Unactivated Reduce the nitro group instead |
| 3,4-Dichloronitrobenzene CAS 99-54-7 | Partially activated Route to 3,4-dichloroaniline |
| 2,4-Dinitrochlorobenzene CAS 97-00-7 | Strongly activated Substitutes under mild conditions |
We supply across the nitro and chloro 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 isomer
m-NCB is not a commodity with a screen price, and it does not track the ortho and para grades. Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
A minority production route
Ortho and para come out of the dominant nitration route in huge volume. Meta does not — it needs a dedicated chlorination of nitrobenzene. Fewer plants, smaller campaigns, and a price that does not follow its isomers down.
- Short producer list worldwide
- Do not benchmark against ortho or para
- Ask us about dual-source contracts
Campaign timing
Because it is campaigned less often, an enquiry landing between campaigns means a genuinely longer lead time. We will tell you that rather than quote a date nobody can hold.
- Quote early for campaign tonnage
- Spot buying off-campaign costs materially more
- Contracted call-off smooths the exposure
Upstream feedstock
The route runs back through benzene, nitrobenzene and chlorine. Benzene economics, nitration acid cost and chlorine availability feed through within a quarter or so.
- Nitrobenzene availability sets the floor
- Chlorine and energy cost weigh on the step
- We flag feedstock-driven moves in the quote
Regulatory pressure
Nitroaromatic production carries real compliance cost — effluent treatment, exposure monitoring, waste handling. That cost sits inside the price and is one reason capacity has consolidated rather than expanded.
- Handling obligations vary by jurisdiction
- Effluent rules shape plant economics
- We check destination rules before quoting
Isomer ceiling
A tight ortho and para limit means more crystallisation passes and lower yield at the plant. If your reduction and downstream separation can tolerate a looser ceiling, say so — it is often the cheapest change available.
- Tighter isomer limits narrow the source list
- Yield loss at the plant is priced in
- 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. On a low-melting solid, routing through hot transhipment ports also carries a caking risk worth pricing in.
- 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
| If your end use is… | Specify |
|---|---|
| Reduction to m-chloroaniline | Tight ortho/para ceiling; low residual nitrobenzene |
| Azo dye & pigment chain | Isomer limit; narrow melting range |
| Agrochemical route | Full impurity profile; retention sample held |
| Pharmaceutical chain | Tight related-substance limit; metals reported |
| Laboratory / R&D | Highest available purity, small DG-compliant pack |
Not sure which column you are in? Describe the step you are running 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
- Confirm the isomer before anything else. Ortho and para are far cheaper and far more available, and a buyer who quotes "nitrochlorobenzene" without the prefix will eventually receive the wrong one from someone.
- Set the isomer ceiling against your actual route. Your reduction will not fix an isomer problem, so the ceiling belongs in the purchase specification rather than in your downstream troubleshooting.
- Be straight about the hazard profile. Toxic by all routes, skin-absorbed and associated with blood effects — stated at enquiry stage so your EHS team can price the controls into the decision.
- 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
- Nitroaromatic obligations are jurisdiction-specific. Several regimes impose exposure monitoring, health surveillance and record retention for this class. Confirm what applies at your site before the first delivery.
- Import controls vary by destination. We check the destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. Confirm your obligations under the applicable inventory regime for your import volume — we will supply the identity data you need for that filing.
- Effluent and waste rules matter because of the aquatic classification. Your site's discharge consent should be checked against the material before it is introduced.
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 giving you 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 121-73-3, the assay, melting range and isomer ceiling you work to, 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 1578 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 Meta Nitrochlorobenzene
Why is the meta isomer harder to get than ortho or para?
Can I displace the chlorine with an amine or alkoxide?
What purity do you normally supply?
In what form does it ship — solid or molten?
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 Meta Nitrochlorobenzene
Send your required assay, 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.