Para Fluoro Aniline
The highest-volume fluoroaniline isomer, supplied by Chelora Chemicals as a building block for fluorinated active pharmaceutical ingredients and agrochemicals — exported from Indonesia with full batch documentation and end-use screening.
What Para Fluoro Aniline is, and why buyers source it
A working overview of the compound's chemistry, its place in the aniline-derivative family, and the grades Chelora Chemicals keeps in regular supply.
Para Fluoro Aniline places its fluorine directly opposite the amino group, and that position is the reason the compound is everywhere in modern medicinal chemistry. The para site is where an aromatic ring is most readily hydroxylated in the body; capping it with fluorine blocks that metabolic pathway while adding almost no steric bulk, so a drug candidate gains metabolic stability without changing shape. The same substitution lowers the ring's electron density and the amine's basicity in a predictable way.
It is an oily liquid at ambient temperature, freezing just below 0 °C at −1.9 °C, colourless to light yellow or gold when fresh and darkening to amber or red-brown with air and light exposure. It is noticeably more water-soluble than the chlorinated anilines at around 33 g/L at 20 °C, and its closed-cup flash point of 73 °C, while higher than the ortho isomer, is still low enough to warrant ignition-source control. Note that combustion products include hydrogen fluoride.
Where it fits in the synthesis chain
Para Fluoro Aniline has the best-documented downstream chain of the fluoroanilines. It is the starting material for the fluoroquinolone antibacterial flumequine, condensed with crotonaldehyde to 6-fluoroquinaldine and carried through cyclisation to the finished ring system. The 4-fluorophenyl groups of the cholesterol absorption inhibitor ezetimibe derive from the same chemistry, and the compound is a recognised reference impurity for that product. It also builds the fungicide fluoroimide — now obsolete and not approved in the EU or Great Britain — and serves as a ligand precursor for α-diimine catalysts used in ethylene polymerisation.
Grades we supply
Chelora Chemicals offers Para Fluoro Aniline in technical grade (99%) and high-purity grade (99.5%+), both with a batch-wise certificate of analysis. Because this material is an API building block, buyers frequently specify individual impurity limits rather than a bulk assay alone; state yours at the enquiry stage. Orders for this grade are subject to end-use screening, as explained below.
How Para Fluoro Aniline is made
An overview of the production route for orientation purposes. Our manufacturing partners' own process parameters and in-process controls are proprietary and are not disclosed beyond what is needed to interpret the certificate of analysis.
Para Fluoro Aniline is made by catalytic hydrogenation of 4-fluoronitrobenzene, over palladium on carbon or Raney nickel, in methanol or ethyl acetate at moderate pressure. The process detail that matters is feed control: holding the nitro compound at a low concentration in the liquid phase throughout the run — in the hundreds of parts per million rather than percent — suppresses the azo and azoxy by-products that form when nitro and partially reduced intermediates accumulate together.
The fluorine itself is installed one step earlier by halogen exchange on 4-chloronitrobenzene: potassium fluoride in anhydrous DMSO at around 170–175 °C with a phase-transfer catalyst added incrementally, giving 4-fluoronitrobenzene in roughly 88–90% yield. The para nitro group activates the ring towards nucleophilic displacement of chloride by fluoride, and it is precisely this activation that makes the para isomer the cheapest and most available of the fluoroanilines.
The Balz–Schiemann route, diazotizing the parent aniline with sodium nitrite and fluoroboric acid and thermally decomposing the tetrafluoroborate salt, remains the classical alternative where Halex activation is unavailable.
End-use screening on this grade
Para Fluoro Aniline appears in the synthesis of parafluorofentanyl, a controlled fentanyl analogue. We therefore run end-use checks on orders for this product as a matter of policy, and may ask about the intended application and end customer before confirming. This is a compliance process applied to every enquiry rather than a judgement about any particular one, and it is the reason our quotation for this grade may take a little longer than for the rest of the range.
Industries and processes that use it
Para Fluoro Aniline is consumed almost entirely as a synthesis intermediate. The four fields below account for most of the demand we see through our export desk.
Fluoroquinolone Antibacterials
The documented starting material for flumequine, condensed with crotonaldehyde to 6-fluoroquinaldine and carried through to the finished ring system.
Active Pharmaceutical Ingredients
The source of the 4-fluorophenyl groups in ezetimibe chemistry, and a general medicinal-chemistry building block where para-fluorination blocks metabolic hydroxylation.
Agrochemicals
An intermediate for herbicides and plant growth regulators, and historically for the fungicide fluoroimide — now obsolete and not approved in the EU or Great Britain.
Catalysis & Analysis
A ligand precursor for α-diimine catalysts used in ethylene polymerisation, and an analytical reagent in enzymic glucose detection.
How the molecule is typically carried forward
The amine is the reactive handle and the para fluorine is a spectator through most of the chemistry — which is exactly its value. It survives the ring-building steps below and arrives in the finished molecule where it is needed.
Skraup / Doebner–Miller Cyclisation
Condensation with crotonaldehyde and ring closure gives 6-fluoroquinaldine, the first intermediate on the documented flumequine route.
Malonate Condensation and Cyclisation
Condensation with diethyl ethoxymethylenemalonate followed by polyphosphoric-acid cyclisation builds the fluoroquinolone ring system.
Acylation
Reaction with an acid chloride or anhydride gives the 4-fluoroanilide, a recurring step in agrochemical and pharmaceutical scaffolds.
Imine and Diimine Formation
Condensation with diketones builds the α-diimine ligands used in late-transition-metal polymerisation catalysts.
Maleimide Formation
Condensation with dichloromaleic anhydride gives the N-(4-fluorophenyl)maleimide structure of the historical fungicide fluoroimide.
Para Fluoro Aniline against its near relatives
Fluorine is the smallest substituent that meaningfully changes an aromatic amine's electronics, and position decides what it is good for. The table below sets out the two fluoroanilines we supply alongside their chlorinated counterparts.
| Product | CAS Number | Typically Used In | Notes |
|---|---|---|---|
| Para Fluoro Aniline | 371-40-4 | Flumequine, fluorinated APIs, agrochemical intermediates | The product on this page — the highest-volume fluoroaniline. |
| Ortho Fluoro Aniline | 348-54-9 | Fused heterocycles, fluorinated pharma and agro intermediates | Lower volume and higher price — see its product page. |
| Para Chloroaniline | 106-47-8 | Chlorhexidine, phenylurea and benzoylurea actives | The chlorinated counterpart — solid, and a Category 1B carcinogen in the EU. |
| Ortho Chloroaniline | 95-51-2 | Sulfonylurea herbicides, azo dyes, MOCA | Liquid chloroaniline, freezes near 0 °C. |
Exact physical constants and purity specifications are confirmed per batch on the certificate of analysis — treat the notes above as a sourcing guide rather than a specification sheet.
Safety classification at a glance
Based on GHS classification as commonly listed for this substance. This is a summary for orientation only — always work from the current safety data sheet supplied with your specific batch.
Harmful if swallowed.
Harmful in contact with skin.
Harmful if inhaled.
Causes severe skin burns and eye damage.
May cause an allergic skin reaction.
Causes damage to organs through prolonged or repeated exposure.
Very toxic to aquatic life with long-lasting effects.
Danger — GHS05 corrosive, GHS07 harmful, GHS08 health hazard and GHS09 environment pictograms apply.
This substance has no harmonised entry in Annex VI to CLP; the classification above reflects supplier self-classification under CLP Article 4(3) and aggregates several notifications, which is why both corrosive and irritant skin endpoints circulate in the market. The Japanese national GHS classification is more lenient, treating the acute oral endpoint as Category 4 and the eye endpoint as Category 2A, and records carcinogenicity and germ-cell mutagenicity as not classifiable for want of data — which is an absence of evidence rather than evidence of absence. No carcinogen or mutagen classification applies from any source and the substance has not been evaluated by IARC. In fire, combustion produces hydrogen fluoride and nitrogen oxides. Transport is UN 2941, Class 6.1, Packing Group III.
Keeping it on spec between delivery and use
General storage guidance for this grade. Site-specific storage rules, segregation requirements and re-test intervals should follow your own EHS procedures and the MSDS issued with your batch.
Store in a cool, dry, well-ventilated area away from ignition sources, protected from light, in tightly closed original containers segregated from oxidizers and strong acids. This material is air-sensitive: it darkens progressively from colourless or light yellow through amber to red-brown, and storage under an inert headspace is recommended where colour matters to the downstream process. That darkening is not in itself an indicator of impurity, so assess the material on its certificate of analysis rather than its appearance. Fire planning should account for hydrogen fluoride among the combustion products.
How it ships from Indonesia
Standard packing and export terms for this product. Confirm exact figures against your order — they vary slightly by destination and quantity.
What travels with every batch
Specification is agreed before the purchase order, not discovered on arrival. Every shipment of Para Fluoro Aniline leaves with a documented, checkable paper trail.
Certificate of Analysis
Batch-wise assay (by GC), isomer purity, melting point range and moisture, issued against the agreed specification so your QC team can check it, not just file it.
Safety Data Sheet
GHS-format SDS in English covering hazard classification, handling, storage, first-aid and spill response for the exact grade shipped.
Technical Data Sheet
Reference physical and chemical properties, recommended storage and typical applications, for internal circulation to your process or R&D teams.
Certificate of Origin
Confirms Indonesian origin for customs clearance and any preferential-duty claim at your destination port.
Dangerous Goods Declaration
UN packing group, classification and shipper's declaration prepared ahead of loading so documentation never holds up customs.
Third-Party Inspection
Independent pre-shipment inspection and re-sampling can be arranged on request, at your cost, for buyers who require it as a matter of policy.
Frequently asked questions
What buyers most often ask our sales desk about this grade.
01What is Para Fluoro Aniline used for?+
02What is the CAS number of Para Fluoro Aniline?+
03What purity grades does Chelora Chemicals supply?+
04Is Para Fluoro Aniline hazardous?+
05Why is the para isomer cheaper and more available than the ortho?+
06Why do you ask about end use for this product?+
07My material has darkened in storage. Is it still usable?+
08What packing options are available?+
09How long does delivery take?+
10Can I get a sample before placing a bulk order?+
11How is Para Fluoro Aniline manufactured?+
12What is the shelf life, and how should it be stored?+
Need Para Fluoro Aniline on spec, on time?
Send us your required purity, quantity, packing preference and destination port. Our desk quotes most enquiries within one working day.