Para Fluoro Aniline 4-Fluoroaniline · CAS 371-40-4

What is Para Fluoro Aniline?

Para Fluoro Aniline, chemically 4-fluoroaniline, is an aromatic amine carrying a fluorine atom para to the amine, formula C₆H₆FN. At room temperature it is a clear liquid ranging from yellow to orange-brown, melting just below 0 °C, so it is handled as a liquid under normal conditions, with a boiling point around 187 °C.

Its value as a building block comes from combining the reactivity of a primary aromatic amine with the metabolic stability and electronic effects that a fluorine substituent brings. Fluorine is a common design feature in modern pharmaceuticals and agrochemicals because it can improve potency, metabolic stability and membrane permeability without adding significant molecular weight, and 4-fluoroaniline is one of the most widely used fluorinated aniline building blocks for introducing that feature.

Commercially, it is produced from 4-fluoronitrobenzene by catalytic reduction, or via diazotisation/fluorination routes from 4-nitroaniline or para-aminoaniline precursors, depending on the producer's preferred chemistry.

4-Fluoroaniline is a regulated chemical, classified for acute oral toxicity and shipped as a Class 6.1 (Packing Group III) dangerous good — a lower severity toxic-goods classification than many other nitroaromatic and chloroaromatic intermediates, but still requiring correct documentation and handling.

Why Para Fluoro Aniline specifically

• A fluorine-introduction building block. Used directly as the aniline fragment in molecules where a para-fluorophenyl group is part of the target structure.
• A documented route to Flumazenil. 4-Fluoroaniline is a named intermediate in the production of this benzodiazepine-antagonist pharmaceutical.
• Herbicide and plant-growth-regulator chemistry. Used as an intermediate in several herbicide and plant-growth-regulator synthesis routes.
• A well-characterised, liquid-handling intermediate. Being liquid at room temperature simplifies dosing and metering compared with many solid aniline intermediates.

How Para Fluoro Aniline is Manufactured

4-Fluoroaniline is made on purpose through a dedicated fluorination and reduction sequence, so supply tracks installed fluorochemical capacity rather than a generic aniline feedstock stream.

• Synthesis of 4-fluoronitrobenzene. A fluorination step (commonly via the Balz-Schiemann reaction on 4-nitroaniline, or halogen exchange chemistry) installs the fluorine on the correct position of the ring.
• Catalytic hydrogenation. The nitro group is reduced to an amine under hydrogen with a metal catalyst, giving 4-fluoroaniline.
• Neutralisation and separation. The reaction mass is neutralised and the amine is separated from catalyst and reaction by-products.
• Purification. The crude liquid is purified by distillation to the target purity, typically 99% or better by GC.
• Finishing and packing. The purified liquid is packed under standard liquid-handling conditions, with attention to colour and moisture.

Typical Commercial Specification

Figures below are representative of commercial-grade 4-fluoroaniline. Tell us your downstream route and the grade you need, and we will advise on the specification to order against.

Physical & Chemical Properties

Behaviour in the process

4-Fluoroaniline's reactivity pattern is what downstream chemists are buying:

• Standard primary-amine reactivity. It undergoes acylation, diazotisation, reductive amination and other standard aniline chemistry without the fluorine interfering in most reactions.
• Metabolic and electronic effects of fluorine. The para-fluorine substituent can block a common site of metabolic oxidation and subtly shift the electron density of the ring, properties that medicinal and agrochemical chemists specifically design around.
• Defluorination in biological systems. Metabolism studies show 4-fluoroaniline itself can be defluorinated in vivo to compounds including paracetamol-related metabolites; this is a toxicology consideration rather than a synthetic one.
• Liquid handling. Being liquid at room temperature, it is straightforward to meter and dose compared with solid aniline intermediates.

Para Fluoro Aniline and Related Fluorinated Anilines

4-Fluoroaniline is one of three monofluoroaniline isomers, and each has distinct chemistry and uses.

Stated plainly: the fluoroaniline isomers are not interchangeable — the position of the fluorine relative to the amine changes both the electronic profile and the metabolic behaviour of molecules built from it, so a synthesis route designed around the para isomer requires that specific isomer.

Industries We Supply Para Fluoro Aniline To

The same liquid amine feeds a pharmaceutical intermediate plant, an agrochemical producer and a dye manufacturer. What changes is the downstream chemistry and the documentation each requires.

Where Para Fluoro Aniline is Used

4-Fluoroaniline is bought almost entirely as a synthesis intermediate. These are the end uses our customers build it into.

In pharmaceutical intermediate manufacture

4-Fluoroaniline's amine reacts under standard conditions to build the fluorophenyl fragment found in Flumazenil and in a range of CNS and anti-inflammatory drug candidates. The para-fluorine substituent is chosen deliberately for the metabolic stability and electronic effects it contributes to the final molecule, which is why purity and colour are specified tightly for pharma-grade material.

In agrochemical and dye manufacture

The same amine reactivity builds herbicide and plant-growth-regulator intermediates, and separately, fluorinated dye and pigment intermediates where the fluorine contributes to the finished product's performance or colour characteristics.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis, with colour and residual nitro compound reported alongside purity because both carry through into pharma and agrochemical intermediate chemistry.

• 4-Fluoroaniline content — by gas chromatography, the primary grade measure.
• Residual fluoronitrobenzene — reported as an under-reduced process impurity.
• Refractive index — a fast purity and identity check.
• Moisture — measured to limits relevant to downstream reaction stoichiometry and storage stability.
• Colour (Hazen / APHA) — tested because darkening carries through to the finished product.

Common Process Problems & Likely Causes

When 4-fluoroaniline causes trouble, it is usually colour, moisture or residual nitro compound. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. HDPE or lined steel drums, typically 200 – 225 kg net, with IBC totes and ISO tanks for bulk orders.
• Light and air protection. Store in closed, shaded containers; minimise headspace to reduce colour drift over time.
• Temperature control. Store at room temperature, away from direct sun and heat sources; it remains liquid above about −2 °C.
• Material compatibility. Avoid contact with strong oxidisers and strong acids.
• Shelf life. Typically 12 months in sealed, properly stored containers; re-test colour and purity on older stock.
• Transport classification. UN 2941, fluoroanilines, Class 6.1 (toxic), Packing Group III. ADR, IMDG, IATA and DOT requirements apply.

Hazards & Safe Handling

4-Fluoroaniline is harmful if swallowed and causes skin and eye irritation on contact. Its hazard profile is lower-severity than many other nitroaromatic and chloroaromatic intermediates, reflected in its Packing Group III toxic-goods classification, but standard precautions still apply.

• Acute toxicity. Harmful if swallowed; avoid ingestion and wash hands thoroughly after handling.
• Skin and eye contact. Causes irritation. Wear chemical-resistant gloves and goggles; remove contaminated clothing immediately on skin contact, and rinse eyes with water for several minutes on eye contact.
• Inhalation. Avoid breathing vapour or mist; use adequate ventilation when handling in open systems.
• PPE. Chemical-resistant gloves and safety goggles as a baseline; respiratory protection where vapour exposure is possible.
• Environment. Avoid uncontrolled release to water; follow local effluent and waste-disposal rules.

Regulatory & Compliance Notes

4-Fluoroaniline is a registered industrial chemical shipped as a lower-severity toxic good. Because obligations differ by territory and use, the notes below are orientation rather than legal advice — confirm your own position with your regulatory adviser.

• GHS classification. Typically classified with hazard statement H302 (harmful if swallowed) and skin/eye irritation statements; the SDS carries the full hazard statements for your grade.
• REACH and chemical inventories. Registered under EU REACH and listed on major chemical inventories.
• Dangerous goods transport. UN 2941, fluoroanilines, Class 6.1, Packing Group III. ADR, IMDG, IATA and DOT requirements apply to packing, labelling and routing.
• HS code. Commonly declared under the aromatic monoamine derivatives heading; confirm the exact tariff line with your customs broker for your jurisdiction.
• Quality agreements. Pharma and agrochemical producers commonly expect documented purity, colour and moisture limits and change control. Tell us what your agreement requires.

We Supply Para Fluoro Aniline Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Para Fluoro Aniline from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged as routing allows.
• Documentation. Commercial invoice, packing list, certificate of origin, COA and SDS issued as a complete set.
• Flexible volumes. From drum trial quantities up to repeat bulk shipments on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying Para Fluoro Aniline from Chelora

We are an independent sourcing and supply partner. For 4-fluoroaniline that means settling three things at enquiry: the purity and colour tolerance your process needs, the packing format, and the quantity you are buying.

• Documentation on every lot. Batch-specific COA with purity, colour and moisture, plus the current SDS.
• Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
• Quantities. Drum trial quantities through to full bulk shipments on contract supply.
• Inspection. Independent third-party inspection available at loading when the contract requires it.
• Related fluorinated intermediates. 3,4,5-Trifluorobromobenzene and other fluorinated building blocks alongside this product from one supplier.

How ordering works

• Send the enquiry. Purity, colour tolerance, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing format and a sample COA, normally within one working day.
• Qualify the supply. For first orders or pharma-grade applications, we share the analysis so your technical team can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
• Ship and document. Packed, labelled and loaded with the full export document set, and tracked through to arrival.

Related Fluorinated Building Blocks & Aniline Intermediates

Buyers of 4-fluoroaniline often source other fluorinated building blocks or aniline intermediates alongside it. Consolidating them cuts freight cost and gives you a single point of contact for documentation.