2,4-Difluoro Nitro Benzene
2,4-Difluoro Nitro Benzene — 2,4-DFNB — pairs an activated nitro group with two differently-placed fluorines, making it one of the more useful nucleophilic aromatic substitution building blocks in fluorochemistry. It is a key route intermediate to 2,4-difluoroaniline, to fluorinated pharmaceutical actives, and to liquid-crystal and agrochemical building blocks.
Chelora Chemicals supplies 2,4-DFNB to pharmaceutical intermediate manufacturers, fine chemical houses and agrochemical formulators, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 446-35-5
- IUPAC name
- 2,4-Difluoronitrobenzene
- Molecular formula
- C6H3F2NO2
- Molecular weight
- 159.09 g/mol
- EC / EINECS
- 207-167-0
- MDL number
- MFCD00007050
- SMILES
- O=[N+]([O-])c1ccc(F)cc1F
- HS Code
- 2904 20*
* Confirm the exact HS heading with your customs broker — classification of nitro-fluoro aromatic intermediates varies between destination tariffs.
What 2,4-Difluoro Nitro Benzene is used for
2,4-Difluoro Nitro Benzene is a nitrobenzene carrying fluorine at the 2- and 4-positions — one ortho, one para to the nitro group. Both fluorines sit on carbons activated toward nucleophilic aromatic substitution by the electron-withdrawing nitro group, which is exactly why the molecule is prized: it is a two-fold electrophile that reacts with amines, alkoxides, thiols and other nucleophiles in a way that plain fluorobenzene never would.
In practice 2,4-DFNB is bought almost entirely as a synthesis intermediate. Reduction of the nitro group gives 2,4-difluoroaniline, a building block in its own right; direct SNAr displacement of one or both fluorines gives fluorinated anilines, ethers and thioethers that feed pharmaceutical, agrochemical and specialty-materials chemistry.
Why the substitution pattern matters
Difluoronitrobenzene isomers are not interchangeable — where the fluorines sit relative to the nitro group decides which carbon reacts first and how cleanly:
- 2,4-Difluoronitrobenzene (CAS 446-35-5) — this product. One fluorine ortho, one para to the nitro group; both activated, with the ortho fluorine typically the more reactive of the two.
- 2,6-Difluoronitrobenzene — both fluorines ortho to the nitro group, a different steric and electronic profile at the reacting carbon.
- 3,4-Difluoronitrobenzene — fluorines meta and para to the nitro group, activated far more weakly and reacting under harsher conditions.
If your purchase order simply says "difluoronitrobenzene", quote us the CAS number and we will confirm the correct material before the order is placed. We also source the reduced derivative, 2,4-difluoroaniline, and related fluoro-nitro building blocks — see our full fluorochemical intermediate range.
Appearance and handling character
2,4-DFNB ships as a clear to light yellow or brown liquid with a melting point of only about 9–10 °C, so it is a liquid at ordinary ambient temperature almost everywhere it is delivered, and can solidify or partially crystallise in a cold store or a winter transit. It is insoluble in water and miscible with most common organic solvents. Like many nitroaromatics it is air- and moisture-sensitive and is best stored under inert gas in a cool, dark place. Read the safety section before planning any handling: the material is toxic if swallowed and irritating to skin, eyes and the respiratory tract, and that should shape your controls from the outset.
| Parameter | Typical value |
|---|---|
| Appearance | Clear, light yellow to brown liquid |
| Assay (GC) | 99.0% min |
| Moisture (KF) | 0.2% max |
| Refractive index (n20/D) | ≈ 1.511 |
| Isomeric & related impurities | 1.0% max |
| Colour (APHA) | Reported per batch |
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. If your process demands a tighter assay, a controlled colour ceiling or a specific isomer limit, send us the specification and we will quote against it rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Liquid at ambient temperature |
| Melting point | ≈ 9 – 10 °C |
| Boiling point | ≈ 203 – 204 °C @ 760 mmHg |
| Flash point | ≈ 90 °C |
| Relative density | ≈ 1.45 (25 °C) |
| Refractive index | n20/D ≈ 1.511 |
| Water solubility | Insoluble |
| Organic solubility | Miscible with most common organic solvents |
| Colour | Light yellow to brown, darkens with age |
Physical constants compiled from public reference data for CAS 446-35-5 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
2,4-DFNB earns its place on a purchasing sheet as a reactive building block, not as a finished product in its own right. Its volume is spread across pharmaceutical, agrochemical and specialty-materials synthesis.
Pharmaceutical intermediates
Sequential SNAr displacement of the two fluorines, or reduction to the aniline, builds fluorinated fragments used across anti-inflammatory, antibacterial and kinase-inhibitor chemistry. The two inequivalent fluorines let a route install two different nucleophiles on the same ring.
- Building block for fluorinated APIs
- Route to 2,4-difluoroaniline by reduction
- See our pharma intermediate range
Agrochemical building block
The same activated-fluorine chemistry that appeals to pharma chemists builds herbicide and fungicide intermediates, where a fluorinated aniline or diaryl ether fragment is required and the second fluorine is left in place as a metabolically stable handle.
- Diaryl ether and aniline intermediates
- Fluorine retained for target-binding chemistry
- See our agrochemical intermediate range
Liquid-crystal materials
Fluorinated nitrobenzenes are a common entry point into the fluorinated aromatic cores used in liquid-crystal display materials, where fluorine substitution tunes dielectric anisotropy and clearing point without adding colour.
- Fluoroaromatic core synthesis
- Electronics and display-material chemistry
- Available in analytical-grade lots on request
Dye & pigment chemistry
Reduced to 2,4-difluoroaniline and diazotised, the molecule feeds fluorinated azo dye and pigment routes where fluorine substitution shifts shade and improves fastness relative to the unsubstituted or chlorinated analogues.
- Diazo component after reduction
- Fluorine substitution shifts shade
- Trial quantities available for shade matching
Fine & custom synthesis
A well-characterised, commercially available two-fold electrophile for custom route scouting — medicinal chemistry teams commonly use it to install a fluorinated aryl fragment with a defined, controllable substitution order.
- Sequential mono- and bis-substitution chemistry
- Available in trial and laboratory quantities
- Technical desk can advise on selectivity
Contract & scheduled supply
API and agrochemical intermediate manufacturers typically run to a campaign schedule rather than a calendar month. We hold contracted inventory and release it against your production plan rather than in one shipment.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply 2,4-Difluoro Nitro Benzene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no fluorination plant — and for a niche, specification-sensitive intermediate like this one, that independence works in your favour. We are never obliged to push you whatever a captive unit happens to be running that month.
Instead we place your order with whichever qualified producer best matches your assay, your colour ceiling, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, or export documentation is delayed, your campaign switches source rather than stalling.
- Specification read against the CAS first. We confirm you need 446-35-5 and not the 2,6- or 3,4-isomer, or the reduced aniline, before we quote a price.
- Batch COA shared before dispatch. You approve the assay, colour and impurity profile against your own spec while the material is still in our warehouse.
- Hazard status stated up front. This material is toxic if swallowed and irritating to skin, eyes and the respiratory tract, and we say so at enquiry stage — not in the small print of a document pack that arrives with the goods.
- Pre-shipment samples for qualification. New account or new source, your R&D team runs a lab batch before the full quantity ever moves.
- Packing chosen for a moisture- and light-sensitive liquid. Amber glass, lined drums and inert-gas headspace are planned with you rather than assumed.
- Export machinery handled in-house. Hazard classification, UN-approved packing, labelling, freight booking and customs paperwork are ours to manage.
- Consolidation onto one bill of lading. Ship 2,4-DFNB alongside other intermediates from our range — one invoice, one shipment, one counterparty.
Packed the way your plant receives it
As a moisture- and light-sensitive liquid, pack format for 2,4-DFNB is not just a cost decision — it protects the assay you are paying for. Tell us how it will be charged at your end and we will quote the format that suits your operation.
Amber glass bottles
UN-certified amber glass with inert headspace, for laboratory samples and light-sensitive small lots where colour and assay stability matter most.
Lined steel or HDPE jerrycans
UN-approved jerrycans with a chemical-resistant liner, the default format for pilot and mid-scale quantities moving by LCL sea freight or air.
Lined steel drums
UN-certified drums with an inert liner for full-container and campaign-scale quantities, giving better protection against moisture pick-up over a long sea transit.
Bulk liquid transport
For contracted annual tonnage moving in ISO tank containers, with nitrogen blanketing arranged at loading to protect colour and assay across a long voyage.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to. Ocean, air and road freight arranged end-to-end with documentation filed before booking.
Campaign despatch
Pharmaceutical and agrochemical intermediate manufacture runs to campaign. We hold contracted tonnage and release it against your production calendar.
Handle this as a toxic, combustible liquid
2,4-Difluoro Nitro Benzene is acutely toxic by ingestion and irritating on contact with skin, eyes and the respiratory tract, and it is a combustible liquid with a flash point around 90 °C. 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
H227Combustible liquid.H301Toxic if swallowed.H315Causes skin irritation.H319Causes serious eye irritation.H335May cause respiratory irritation.
Hazard statements reflect the harmonised GHS classification commonly published for CAS 446-35-5. Supplier classifications may differ in detail; always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the drum arrives, not after it leaks. 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.
- Contain, do not hose to drain. Absorb spilled liquid onto an inert absorbent and collect into a labelled, sealed container for disposal as chemical waste.
- Eliminate ignition sources. The flash point sits around 90 °C, so hot processes and open flame near the storage or transfer point should be controlled.
- Assume skin and eye contact risk. Chemical-resistant gloves, goggles and coveralls should be worn for any transfer or sampling operation.
- Have the SDS with the casualty. If ingestion, inhalation or significant skin contact occurs, the treating clinician needs the product identity and CAS number in hand.
- Ventilate the work area. Respiratory irritation (H335) means transfer and sampling should happen with adequate local exhaust ventilation.
Storage
- Cool, dry, well-ventilated store, ideally below 15 °C, away from direct sunlight and heat sources. The melting point of only 9–10 °C means the material is a liquid at most ambient storage temperatures.
- Keep containers tightly closed and under inert gas where practical. Air and moisture ingress drive colour drift and can degrade assay over time.
- Segregate from strong bases and strong oxidising agents, with which this nitroaromatic is incompatible.
- Access-controlled storage, away from ignition sources given the combustible-liquid classification.
- Shelf life is typically 12–18 months in sealed original packing under these conditions. Re-assay before use after long storage.
Handling & PPE
- Closed transfer where practical. Pumped or gravity transfer through a closed line limits both vapour exposure and moisture pick-up.
- Skin and eye protection — chemical-resistant gloves, splash goggles and coveralls for any sampling, charging or drum-opening operation.
- Respiratory protection where vapour concentration may build up, particularly in a poorly ventilated charging area — per your own exposure assessment.
- Keep away from heat and open flame given the combustible-liquid classification and the moderate flash point.
- Never discharge to drain or watercourse. Collect any spillage as regulated chemical waste.
Transport
2,4-DFNB moves as regulated cargo. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made. The applicable UN number, class and packing group are 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, moisture by Karl Fischer, colour, refractive index and impurity profile — 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 number, 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.
Why two fluorines beat one
Almost every route built on 2,4-DFNB exploits the fact that it carries two chemically distinct, independently displaceable fluorines. Understanding the reactivity difference between them explains why the molecule is worth paying a premium over a single-fluorine nitrobenzene. The pattern below is the general industrial picture, not a process disclosure.
Start with the ring
The nitro group at C1 activates both the ortho (C2) and para (C4) positions toward nucleophilic aromatic substitution — that is exactly where the two fluorines sit.
First substitution
The ortho fluorine (C2) is generally the more reactive of the two, so a controlled first equivalent of nucleophile displaces it selectively under mild conditions.
Second substitution
The remaining para fluorine (C4) is displaced under somewhat firmer conditions, allowing a second, different nucleophile to be installed if the route calls for it.
Or reduce first
Alternatively, the nitro group is reduced to the amine before either fluorine is touched, giving 2,4-difluoroaniline as a standalone building block for amide, urea and heterocycle chemistry.
Why feed quality carries through the whole route
Both the substitution and the reduction pathway are sensitive to what else is in the feed:
- Isomeric difluoronitrobenzenes react at different rates and can give a mixture of substitution products that is difficult to separate from the target compound.
- Residual moisture competes as a nucleophile in SNAr chemistry, hydrolysing reagent and reducing yield at the first substitution step.
- Colour bodies from oxidation can carry through a reduction step and show up as an off-colour aniline product.
- Trace metals or catalyst poisons matter directly if your route reduces the nitro group with a supported metal catalyst rather than a stoichiometric reagent.
That chain of consequences is the reason we quote against your written specification rather than a generic "99% technical" grade, and the reason the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Intermediate | Principal outlet |
|---|---|
| 2,4-Difluoronitrobenzene CAS 446-35-5 — this product | Pharmaceutical & agro intermediates Liquid-crystal cores 2,4-Difluoroaniline route |
| 2,6-Difluoronitrobenzene | Symmetrical substitution routes Specialty aniline chemistry |
| 3,4-Difluoronitrobenzene | Slow-reacting SNAr routes Speciality fluoroaniline chemistry |
If your route calls for a different fluoro-nitro isomer, or for the reduced aniline directly, we source those as well — see our full fluorochemical intermediate range. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
2,4-DFNB is a niche, specification-driven intermediate rather than a screen-priced commodity. Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Fluorination capacity is limited
Selective aromatic fluorination is a narrower slice of the chemical industry than chlorination or nitration, so fewer plants make this molecule and lead times are longer than for a commodity aromatic.
- Quote early for campaign tonnage
- Spot lots are the exception, not the rule
- Contracted call-off smooths the exposure
Fluorine feedstock cost
Anhydrous hydrogen fluoride and potassium fluoride are the working fluorinating agents behind most routes to this molecule, and their pricing feeds through to the finished intermediate within a quarter or so.
- HF/KF pricing sets a cost floor
- Energy cost weighs on the fluorination step
- We flag feedstock-driven moves in the quote
Purity demands a premium
Pharmaceutical-grade lots with a tight colour and isomer specification cost meaningfully more than a technical grade, because the extra purification step removes yield as well as adding process time.
- Colour ceiling is often the cost driver
- Isomer limits tighten cost further
- We check whether the tighter spec is actually needed
Pack format & stability
Amber glass and inert-gas headspace cost more than a plain lined drum, but they protect colour and assay across a long transit — a false economy on packing can show up as an out-of-spec COA at destination.
- Small amber-glass lots carry the highest packing cost
- ISO tank is cheapest per kilo at contract volume
- We plan pack format around your storage conditions
Freight & DG surcharges
This is regulated, combustible cargo, so ocean freight 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, feedstock allocation or an environmental review can take a fluorination unit offline at short notice. 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 |
|---|---|
| Pharmaceutical intermediate route | High assay, tight colour ceiling, low isomer content |
| Agrochemical intermediate route | Standard commercial assay, isomer limit as agreed |
| Liquid-crystal / electronics | High assay, controlled colour, trace-metal limits |
| Reduction to the aniline | Low colour-body content to avoid off-colour product |
| Laboratory / R&D | Small pack, high purity, full analytical pack |
Not sure which row you are in? Describe the reaction 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
- Match a grade to your reaction. Tell us the step you are running and we will recommend the specification — and say so plainly when a tighter, costlier grade would add nothing.
- Be straight about the hazard profile. We state the acute toxicity and combustibility classification at enquiry stage so your EHS team can price the controls into the decision, rather than meeting it for the first time on the label.
- Advise on handling and storage for your site conditions — a cool store below 15 °C is a different problem for a plant in the tropics than for one in a temperate climate.
- 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
- Import controls vary by destination. Some jurisdictions apply registration, licensing or end-use declaration requirements to nitroaromatic intermediates. 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.
- Workplace exposure limits for nitroaromatics vary by jurisdiction. Confirm what applies at your site before the first delivery.
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 446-35-5, the assay and colour 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
DG classification filed, freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
Often bought alongside this grade
Consolidate several intermediates onto one shipment and one invoice. These are the fluoro- and nitro-aromatics our pharmaceutical, agrochemical and fine chemical customers most often order in the same programme. Browse the full range on our products page — individual specification sheets are available on request.
What buyers ask us about 2,4-Difluoro Nitro Benzene
Is this material hazardous to handle?
Can I use the 2,6- or 3,4-isomer instead?
What purity do you normally supply?
What is the minimum order quantity?
How long does delivery take?
The liquid arrived partly solidified. Is it off-spec?
Why does the liquid darken in storage?
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?
Can you hold stock against a production plan?
Request pricing on 2,4-Difluoro Nitro Benzene
Send your required assay, 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 bottle or a contracted ISO-tank programme for the year.