3,4-Dichloronitrobenzene
3,4-Dichloronitrobenzene exists commercially for one overwhelming reason: it is the practical industrial route to 3,4-dichloroaniline. That amine is the structural core of several of the highest-volume herbicides ever manufactured, and the adjacent chlorine pair it carries is what gives those molecules their activity.
Chelora Chemicals supplies 3,4-DCNB to agrochemical producers, pigment manufacturers and fine chemical plants worldwide, in UN-approved packing, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 99-54-7
- IUPAC name
- 1,2-Dichloro-4-nitrobenzene
- Molecular formula
- C6H3Cl2NO2
- Molecular weight
- 191.99 g/mol
- EC / EINECS
- 202-764-2
- UN Number
- 1578 · Class 6.1
- SMILES
- Clc1ccc(cc1Cl)[N+](=O)[O-]
- 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 3,4-Dichloronitrobenzene is used for
3,4-DCNB is a pale yellow crystalline solid that melts just above ambient, around 42 °C. Structurally it is nitrobenzene with chlorines at the 3- and 4-positions — and those two chlorines are not equivalent. The one para to the nitro group is activated toward nucleophilic substitution; the one meta to it is not. That asymmetry is what makes selective chemistry on this molecule possible.
In practice, though, most buyers are not substituting anything. They are reducing the nitro group and keeping both chlorines, because the product they want is 3,4-dichloroaniline — the amine at the heart of diuron, linuron, propanil and related herbicide chemistry, and a diazo component in azo pigment manufacture. The chlorine pattern survives the reduction intact, which is exactly the point.
Why the isomer is the whole specification
Dichloronitrobenzenes share a formula, a molecular weight and a general appearance. What they do not share is the aniline they become:
- 3,4-Dichloronitrobenzene (CAS 99-54-7) — this product. Reduces to 3,4-dichloroaniline, the herbicide building block.
- 2,5-Dichloronitrobenzene (CAS 89-61-2) — reduces to 2,5-dichloroaniline, used mainly in azo pigment chemistry. See that page.
- Meta nitrochlorobenzene (CAS 121-73-3) — a single chlorine, meta and unactivated; reduces to m-chloroaniline. See that page.
- 2,4-Dinitrochlorobenzene (CAS 97-00-7) — the inverse structure, where substitution rather than reduction is the dominant chemistry. See that page.
An isomer error here is not recoverable downstream — you get the wrong aniline and therefore the wrong active. Always quote the CAS number on your purchase order, and see the full intermediate range.
Appearance and handling character
The material ships as a pale yellow crystalline solid or flake, practically insoluble in water and soluble in alcohol, benzene and acetone. The low melting point matters logistically: a container standing in the sun can soften or cake the product, which is a handling problem rather than a quality one but worth planning for. It is toxic by all three exposure routes, absorbed through intact skin, and a cause of methaemoglobinaemia. 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 | 41 – 43 °C |
| Isomer content | Reported per batch |
| Residual mono-chloro | 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 the isomer figure usually matters more than the headline assay — an isomeric impurity reduces to the wrong aniline and reports as an active-level contaminant, not a removable one.
| Property | Value |
|---|---|
| Physical state | Solid at ambient; melts just above |
| Melting point | ≈ 41 – 43 °C |
| Boiling point | ≈ 255 – 256 °C @ 760 mmHg |
| Flash point | ≈ 130 °C |
| Relative density | ≈ 1.46 |
| Water solubility | Practically insoluble |
| Organic solubility | Soluble in alcohol, benzene, acetone |
| Reactivity | Chlorine para to nitro is the activated one |
Physical constants compiled from public reference data for CAS 99-54-7 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
One route dominates — reduction to the dichloroaniline — but the markets that route feeds are quite different from one another.
Herbicide intermediates
Reduction gives 3,4-dichloroaniline, which is then converted to the urea and anilide herbicides — diuron, linuron, propanil and their relatives. This is the single largest outlet for the material worldwide.
- Urea and anilide herbicide chains
- Isomer purity carries to the active
- See our agrochemical intermediate range
Azo dye & pigment chemistry
3,4-Dichloroaniline diazotises and couples like any aromatic amine, and the chlorine pair raises lightfastness and shifts shade — which is why chlorinated anilines are so common in pigment structures.
- Diazo component for azo pigments
- Chlorination improves fastness
- See our dye intermediate range
Selective substitution routes
Where a route needs the chlorine replaced rather than retained, the one para to the nitro group is the reactive site — allowing a selective mono-substitution the meta chlorine will not undergo under the same conditions.
- Activated chlorine para to nitro
- Alkoxy, amino and thio substitution
- Technical desk review of your step
Pharmaceutical & fine chemical
Dichlorinated aromatic amines appear in a range of fine chemical and pharmaceutical synthesis routes where the halogen pattern is carried through to the finished structure.
- Tight related-substance limits usually apply
- Custom synthesis quantities available
- Full impurity profile on request
Laboratory & development use
Process development groups use small quantities when scoping a reduction or evaluating a selective substitution against an alternative isomer.
- Reagent-grade material on request
- Small DG-compliant packs
- Full analytical documentation available
Contract & seasonal supply
Herbicide manufacture is seasonal, and intermediate buying runs well ahead of it. Most buyers want tonnage released against a production plan rather than in one shipment. We hold inventory and release it to your schedule.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply 3,4-Dichloronitrobenzene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no chlorination or nitration plant — and on an isomer-critical product feeding registered agrochemical actives, that independence lets us route your order to a producer whose isomer control and documentation genuinely match what your registration requires.
We place your order with whichever qualified producer best matches your isomer limit, your assay, 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. 3,4 or 2,5 — we settle that in the first reply, because an isomer error on this product is not recoverable downstream.
- Isomer figure on the COA, not averaged away. It is reported as a number in its own right, because that is what your reduction step actually responds to.
- 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.
- Registration documentation supported. Where the material feeds a registered active, we work with you on the identity and impurity data your dossier needs, and lock the source after qualification.
- Hazard status stated up front. Toxic by all routes, skin-absorbed, methaemoglobin-forming — said 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 just above ambient, pack choice and transit conditions interact. Tell us how the material will be charged at your end and we will quote accordingly.
UN-approved drums
Fibre or HDPE drums with inner liner, UN-certified for Class 6.1 solids — the standard commercial format for flake and crystalline product.
Large drums
Larger UN drums for high-volume users with mechanical handling and closed charging, cutting cost per kilo and the number of openings your operators make.
Molten movement
With a melting point near 42 °C, molten handling is practical for buyers with heated receipt facilities — subject to the DG position for your destination.
Samples & trial packs
Laboratory and pilot quantities dispatched so your team can confirm isomer profile and reduction behaviour before committing to campaign volume.
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.
Season-aligned despatch
Herbicide manufacture is seasonal. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Handle this as a toxic, skin-absorbed solid
3,4-Dichloronitrobenzene is toxic by the oral, dermal and inhalation routes, absorbed through intact skin, associated with methaemoglobin formation, and 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.H410Very toxic to aquatic life with long lasting effects.
Hazard statements reflect classifications commonly published for CAS 99-54-7. Some suppliers list the aquatic entry as H411 and add skin or eye irritation statements. Chloronitroaromatics as a class are associated with methaemoglobin formation. Always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the drum arrives. 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.
- Methaemoglobinaemia can be delayed. Cyanosis, headache and breathlessness may appear hours after exposure. Any suspected exposure needs medical assessment rather than a wait-and-see.
- Skin is a primary route. Contaminated clothing continues to deliver dose — remove it immediately and wash thoroughly.
- Watch the melting point in a spill. Warm conditions can leave you dealing with a liquid rather than a solid, which spreads and penetrates far faster.
- Collect solids mechanically, avoid raising dust, and never hose spillage to drain — the aquatic classification applies.
- 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, away from direct sunlight and heat. The low melting point makes a hot warehouse a practical problem, not just a theoretical one.
- 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, alkalis and strong oxidisers in storage as well as in process.
- 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; ventilation second; PPE last.
- Skin protection is the priority. Chemical-resistant gloves and coveralls, not just splash protection — this material passes through intact skin.
- Respiratory protection during drum opening, charging and any dust-generating or molten-handling operation, per your own exposure assessment.
- Health surveillance. Where methaemoglobin-forming agents trigger obligations at your site, your occupational health provider owns the detail.
- Never discharge to drain or watercourse. Contain spills and dispose of them as regulated chemical waste.
Transport
The material moves as regulated cargo under UN 1578, 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, melting range, isomer distribution 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 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.
Two chlorines, only one of them reactive
The asymmetry between the two chlorines defines what can be done to this molecule. The routes below are the general industrial pattern, not a process disclosure.
Chlorinate and nitrate
o-Dichlorobenzene is nitrated, placing the nitro group para to one chlorine and meta to the other — the arrangement that defines this isomer.
Separate the isomers
Nitration gives a distribution, not a single product. Crystallisation and distillation separate the wanted isomer, and melting range shows how well.
Reduce the nitro group
Catalytic or chemical reduction converts nitro to amine while leaving both chlorines in place, giving 3,4-dichloroaniline.
Build the active
The aniline is converted to the urea or anilide herbicide, or diazotised and coupled into a pigment structure.
Why feed quality carries through the whole route
A reduction step is unforgiving. Whatever nitro-bearing species you charge becomes an aniline, and anilines are far harder to separate from each other than their nitro precursors were:
- Isomeric dichloronitrobenzenes reduce to isomeric dichloroanilines, which couple or react onward into an active with the chlorines in the wrong place — and show up in the registered impurity profile of your finished product.
- Residual mono-chloronitrobenzene reduces to a mono-chloroaniline, a structurally different contaminant that your downstream purification was never designed to remove.
- Melting range is the fastest practical read on isomer purity and is worth tracking batch to batch alongside the GC assay.
- Moisture affects catalyst performance in the reduction and is reported separately for that reason.
For a buyer feeding a registered agrochemical active, that chain of consequences is the reason we share the batch COA for approval before dispatch rather than sending it with the invoice.
| Intermediate | Reduces to |
|---|---|
| 3,4-Dichloronitrobenzene CAS 99-54-7 — this product | 3,4-Dichloroaniline Herbicide chain |
| 2,5-Dichloronitrobenzene CAS 89-61-2 | 2,5-Dichloroaniline Azo pigment chain |
| Meta nitrochlorobenzene CAS 121-73-3 | m-Chloroaniline Dye and agrochemical chain |
We supply across the chloronitrobenzene family — see the full intermediate range. Send the CAS number and we will confirm the correct isomer before quoting.
What actually moves the price of this intermediate
This is not a commodity with a screen price. Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Agricultural seasonality
Herbicide demand is seasonal and hemispheric, and intermediate buying runs one to two quarters ahead of application season. Quoting at the top of that cycle costs materially more than quoting against a contract.
- Quote well ahead of application season
- Spot buying at peak costs more
- Contracted call-off smooths the exposure
Upstream feedstock
The route runs back through benzene, chlorination to o-dichlorobenzene and mixed-acid nitration. Benzene, chlorine and acid economics feed through within a quarter or so.
- Dichlorobenzene availability sets the floor
- Chlor-alkali economics matter here
- We flag feedstock-driven moves in the quote
Isomer separation cost
Nitration produces a distribution. The tighter your isomer ceiling, the more separation work the plant must do and the fewer plants can meet it — which is precisely what a premium grade is buying you.
- Tight isomer limits narrow the source list
- Co-isomer demand affects economics
- We will tell you when you are over-specifying
Regulatory pressure
Chloronitroaromatic production carries heavy compliance cost — effluent treatment, exposure monitoring, waste handling — and herbicide registrations downstream add their own documentation burden.
- Registration changes shift demand quickly
- Obligations vary by jurisdiction
- We check destination rules before quoting
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 — and on a seasonal product, a two-week slip can cost you the season.
- 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 |
|---|---|
| Registered herbicide active | Tight isomer limit; full profile; source locked after qualification |
| Azo pigment chain | Isomer limit; colour-relevant impurities reported |
| Selective substitution | Low moisture; consistent assay batch to batch |
| Pharmaceutical chain | Related substances and 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. It is the single most consequential detail on this product line, and we settle it in the first reply.
- Match a grade to your step. A reduction feeding a registered active and a selective substitution need different things from the same molecule.
- Support registration documentation. Where the material feeds a registered agrochemical, we work with you on identity and impurity data and lock the source after qualification.
- 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
- Agrochemical supply chains are documentation-heavy. Source changes can require notification under a registration. Tell us at enquiry stage if that applies, because it changes how we route the order.
- 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. Check your site's discharge consent against the material before introducing it.
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 99-54-7, the assay, melting range and isomer limits 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 3,4-Dichloronitrobenzene
How is this different from the 2,5-isomer?
What is it mainly used to make?
Can both chlorines be substituted?
What purity do you normally supply?
In what form does it ship?
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 manufacture this yourself?
Request pricing on 3,4-Dichloronitrobenzene
Send your required assay, isomer ceiling, melting range, 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 season programme.