2,4-Difluoro Nitro Benzene
A high-purity fluorinated nitroaromatic supplied for pharmaceutical and agrochemical intermediate synthesis, where the activated fluorines drive selective nucleophilic substitution.
What is 2,4-Difluoro Nitro Benzene?
2,4-Difluoro Nitro Benzene — 24DFNB — is a pale yellow liquid carrying a nitro group with fluorines at the 2 and 4 positions. It is one of the more useful electrophilic building blocks in fluorinated fine chemical synthesis.
Aryl fluorine is normally inert, but here the nitro group activates both fluorines toward nucleophilic aromatic substitution, and the ortho fluorine reacts preferentially. Amines, alkoxides, and thiolates displace it under mild conditions, giving a clean route to substituted nitroaromatics that would be hard to build any other way.
At Chelora Chemicals, 24DFNB is distilled to high assay with isomer content and moisture tightly controlled, since impurities introduced at this stage propagate through every subsequent step of a pharmaceutical or agrochemical route.
- Appearance
- Pale yellow to yellow liquid
- Odour
- Faint aromatic
- Solubility
- Insoluble in water; soluble in most organic solvents
- Function
- Chemical intermediate
- Grade
- High purity / pharma intermediate
Formula diagram
Nitro group with activated fluorines at the ortho and para positions
- Molecular formulaC6H3F2NO2
- Molecular weight159.09 g/mol
- IUPAC name2,4-Difluoro-1-nitrobenzene
- Functional groupsNitro, aryl fluoride
- CAS number446-35-3
Technical product information
Standard specification for Chelora Chemicals' high-purity pharma-intermediate grade 2,4-Difluoro Nitro Benzene. Custom-grade and bulk specifications are available on request.
| Chemical name | 2,4-Difluoro Nitro Benzene |
|---|---|
| Synonyms | 24DFNB, 2,4-Difluoronitrobenzene, 1-Nitro-2,4-difluorobenzene |
| CAS number | 446-35-3 |
| Molecular formula | C6H3F2NO2 |
| Molecular weight | 159.09 g/mol |
| Assay (GC purity) | ≥ 99.0% |
| Appearance | Clear, pale yellow to yellow liquid |
| Density (20°C) | 1.42–1.45 g/cm³ |
| Boiling point | 96–98°C at 20 mmHg |
| Freezing point | below 0°C |
| Flash point | > 90°C (closed cup) |
| Refractive index (20°C) | 1.510–1.518 |
| Water content | ≤ 0.1% |
| Packaging | 25 kg & 200 kg drums |
| Shelf life | 24 months in sealed original packaging |
Applications of 2,4-Difluoro Nitro Benzene
Pharmaceutical intermediates
A key electrophile in API routes where an amine or alkoxide displaces the activated ortho fluorine.
Antibacterial synthesis
Used in building fluorinated aromatic cores found in quinolone and related antibacterial scaffolds.
Agrochemical intermediates
Introduces a difluorinated nitroaromatic fragment into crop-protection actives.
Heterocyclic chemistry
Substituted then reduced to give aminonitro intermediates that cyclise to benzimidazoles and related rings.
Liquid crystal & materials
Applied in fluorinated intermediates for specialty electronic and display materials.
Custom synthesis
Supplied as a research and development building block for selective aromatic substitution chemistry.
Why choose Chelora Chemicals
Every batch of 2,4-Difluoro Nitro Benzene is manufactured, tested, and documented to a standard that formulators and process chemists can build on with confidence — from first sample to full production volume.
Consistent purity
GC assay controlled at ≥99% with isomer profile and low moisture verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From 25 kg drums to 200 kg drums, with laboratory samples for development work.
Technical support
Process, handling, and compliance guidance from our chemistry team.
Storage and guidelines
- 01Store in tightly sealed original containers in a cool, dry, well-ventilated store.
- 02Keep below 25°C, away from heat, sparks, open flame, and direct sunlight.
- 03Protect from moisture; water reduces yield in subsequent substitution chemistry.
- 04Segregate from strong bases, amines, strong oxidising agents, and reducing agents.
- 05Use compatible containers: glass, stainless steel, or lined steel, blanketed with nitrogen where practical.
- 06Prevent release to drains, surface water, and soil, and bund all bulk storage.
Handling precautions
24DFNB is harmful if swallowed, inhaled, or absorbed through skin, and causes skin and eye irritation. It is for industrial use by trained personnel only.
Nitroaromatics can be absorbed through intact skin and may affect the blood by forming methaemoglobin. Chemical-resistant gloves, coveralls, and eye protection are required.
Reaction with amines and other nucleophiles is exothermic and can accelerate sharply at scale. Substitution chemistry using this product needs its own thermal risk assessment and controlled addition.
Contact with strong bases or reducing agents can be violent, and nitroaromatics can decompose exothermically at elevated temperature. Avoid overheating during distillation or drying.
Refer to the full Safety Data Sheet for exposure limits, fire-fighting measures, spill response, and first-aid information before use.
Frequently asked questions
What is 2,4-Difluoro Nitro Benzene used for?
It is an electrophilic building block for pharmaceutical and agrochemical synthesis, particularly where an amine, alkoxide, or thiolate is used to displace one of the activated fluorines and build a substituted nitroaromatic core.
Why are the fluorines reactive here when aryl fluorine is usually inert?
The nitro group withdraws electron density and stabilises the negatively charged intermediate formed when a nucleophile attacks the ring. Under that activation, fluorine actually becomes the best leaving group of the halogens for this reaction type.
Which fluorine reacts first?
The ortho fluorine, at position 2, is displaced preferentially because it sits directly adjacent to the nitro group and benefits most from that activation. This selectivity is what makes the molecule synthetically useful rather than simply reactive.
Can both fluorines be displaced?
Yes, under more forcing conditions or with excess nucleophile, which is sometimes the goal and sometimes an unwanted by-product. Controlling stoichiometry, temperature, and addition rate is what keeps the reaction mono-substituted.
Is it soluble in water?
No. It is practically insoluble in water and readily soluble in DMF, DMSO, acetonitrile, THF, and most solvents used for nucleophilic aromatic substitution.
Why is water content specified?
Residual water competes with the intended nucleophile, consumes base, and reduces yield. For substitution chemistry at scale, a low and consistent moisture figure is a functional requirement.
What purity do you supply?
Standard grade is supplied at a minimum GC assay of 99% with water content at or below 0.1%. Tighter isomer, metals, and colour specifications can be manufactured for pharmaceutical intermediate use.
What packaging sizes are available?
25 kg and 200 kg drums, with laboratory and pilot samples available for development and qualification work.
What are the main process safety concerns?
Two: the substitution reaction with amines is exothermic and can run away if added too quickly at scale, and nitroaromatics in general can decompose exothermically if overheated during work-up or distillation. Both need a documented thermal assessment.
How should it be stored?
In sealed original containers below 25°C in a cool, dry, ventilated store, protected from moisture and segregated from bases, amines, and oxidising agents.
Do you provide a Certificate of Analysis?
Yes. Every batch is dispatched with a Certificate of Analysis and Safety Data Sheet covering GC assay, refractive index, density, water content, and appearance.