2-Chloro-4-fluoro-5-nitroaniline: Handling & Use Protocol

2-Chloro-4-fluoro-5-nitroaniline is a multifunctionally substituted aromatic amine building block bearing chloro, fluoro, and nitro groups on the aniline ring, making it a versatile intermediate for the synthesis of pharmaceuticals, agrochemicals, and specialty fine chemicals.

Chemical Name

2-Chloro-4-fluoro-5-nitroaniline

Molecular Formula

C₆H₄ClFN₂O₂

Molecular Weight

190.56 g/mol

Key Functional Groups

Primary amine (–NH₂), nitro (–NO₂), chloro (–Cl), fluoro (–F)

Recommended Storage

Cool, dry, well-ventilated location; away from heat, ignition sources, and incompatible oxidizers

Primary Applications

Pharmaceutical and agrochemical synthesis, dye chemistry, heterocyclic building block preparation

Aladdin SKU

C768388

Safety and Personal Protective Equipment

2-Chloro-4-fluoro-5-nitroaniline is an aromatic amine containing a nitro group and should be treated as a potentially toxic and irritant compound. Before working with this reagent, consult the current Safety Data Sheet (SDS) provided by Aladdin Scientific.

Required PPE:

• Chemical-resistant gloves (nitrile or neoprene, minimum 0.3 mm thickness)
• Safety goggles or face shield
• Laboratory coat or chemical-resistant apron
• Closed-toe shoes

Engineering Controls: All weighing, dissolution, and reaction steps must be performed inside a well-functioning chemical fume hood to prevent inhalation of dust or vapors. Avoid generating fine particulates during transfer.

First Aid: In case of skin or eye contact, flush immediately with copious amounts of water for at least 15 minutes and seek medical advice. If inhaled, move to fresh air; if ingested, do not induce vomiting and contact a poison control center immediately.

Waste Disposal: Dispose of all residues and contaminated materials in accordance with local, regional, and national regulations governing halogenated aromatic amine waste streams.

Storage and Stability

Store 2-Chloro-4-fluoro-5-nitroaniline in a tightly sealed container in a cool (below 25 °C), dry, and well-ventilated area, away from direct sunlight, heat sources, and incompatible materials such as strong oxidizing agents, strong acids, and strong bases.

Container compatibility: Use amber glass or high-density polyethylene (HDPE) containers to minimize light-induced degradation. Ensure lids are firmly closed after each use to prevent moisture uptake and oxidation.

Shelf life: When stored under recommended conditions, the reagent is expected to maintain specification-grade purity over its labeled shelf life. Verify purity by TLC or HPLC if the material has been stored for an extended period or if discoloration is observed.

Incompatibilities: Avoid contact with strong oxidizers (e.g., permanganates, peroxides), strong reducing agents, and reactive halogenating agents, which may cause vigorous or hazardous reactions.

Solution Preparation and Handling Procedure

The following procedure describes the preparation of a stock solution of 2-Chloro-4-fluoro-5-nitroaniline for use in synthetic reactions. Perform all steps in a chemical fume hood.

Materials required:

• 2-Chloro-4-fluoro-5-nitroaniline (Aladdin SKU: C768388)
• Analytical balance (±0.1 mg precision)
• Appropriate organic solvent (e.g., dimethyl sulfoxide, N,N-dimethylformamide, ethanol, or dichloromethane, depending on downstream application)
• Volumetric flask or graduated vial
• Magnetic stir bar and stir plate (if required)

Procedure:

1. Don all required PPE before beginning.
2. Tare a clean, dry vial or weigh boat on the analytical balance.
3. Carefully weigh the required amount of 2-Chloro-4-fluoro-5-nitroaniline and record the exact mass.
4. Transfer the solid to the appropriate volumetric container. Rinse the weigh boat with a small aliquot of solvent to ensure quantitative transfer.
5. Add approximately 80% of the final target solvent volume. Stir or sonicate gently until fully dissolved.
6. Bring to final volume with additional solvent and mix thoroughly.
7. Label the container with compound name, concentration, date of preparation, preparer's initials, and hazard information.
8. Store the prepared solution under the same conditions as the neat solid unless otherwise indicated by the specific application protocol.

Note: Solubility in aqueous systems is limited; organic solvents such as DMSO or DMF are generally preferred for stock solution preparation.

Synthetic Applications

2-Chloro-4-fluoro-5-nitroaniline is a valuable multifunctional building block in organic synthesis, offering three distinct reactive handles on the aromatic ring:

• Primary amine (–NH₂): Participates in diazotization, acylation, sulfonylation, reductive amination, and condensation reactions to form amides, sulfonamides, imines, and azo dyes.
• Nitro group (–NO₂): Can be selectively reduced to an additional amine functionality (using catalytic hydrogenation, iron/acetic acid, or SnCl₂ reduction), affording 1,2-diamine derivatives useful for heterocyclic ring construction (e.g., benzimidazoles, quinoxalines).
• Chloro substituent (–Cl): Activated toward nucleophilic aromatic substitution (S_NAr) by the electron-withdrawing nitro group at the adjacent position, enabling displacement with amines, alkoxides, thiols, and other nucleophiles under mild to moderate conditions.
• Fluoro substituent (–F): The C–F bond can also participate in S_NAr under appropriate nucleophile and condition selection, and fluorine incorporation confers favorable metabolic stability and lipophilicity in drug candidate molecules.

Typical transformations include preparation of fluorinated diaminobenzene intermediates, synthesis of substituted benzimidazoles and quinoxalines, and use as a precursor in agrochemical active ingredient synthesis. Reaction conditions should be optimized based on the specific transformation and the literature relevant to analogous substrates.

Quality Control and Analytical Characterization

Prior to use in sensitive synthetic sequences, verify the identity and purity of 2-Chloro-4-fluoro-5-nitroaniline using one or more of the following analytical methods:

Thin-Layer Chromatography (TLC): Run on silica gel plates using an appropriate eluent (e.g., hexane/ethyl acetate mixtures). Visualize under UV light (254 nm). A single spot consistent with the reference Rf value indicates acceptable purity.

High-Performance Liquid Chromatography (HPLC): Reverse-phase HPLC (C18 column, UV detection at 254 nm or 280 nm, gradient elution with water/acetonitrile) provides quantitative purity assessment. Purity ≥98% (area percent) is typically acceptable for synthetic applications.

¹H and ¹⁹F NMR Spectroscopy: Confirm structural identity. The aromatic region will show two singlet-like proton signals corresponding to the two ring hydrogens. ¹⁹F NMR will confirm the presence and chemical shift of the fluorine substituent. The NH₂ protons appear as a broad signal.

Melting Point: Determine melting point and compare to literature or supplier-reported values as an additional identity check. Flag significant deviations for investigation.

Review flag: Specific Rf, HPLC retention time, NMR chemical shifts, and melting point values should be sourced from the product specification sheet provided by Aladdin Scientific (SKU C768388) or peer-reviewed literature and confirmed before recording in laboratory notebooks.

Frequently asked questions

What solvents are suitable for dissolving 2-Chloro-4-fluoro-5-nitroaniline?

2-Chloro-4-fluoro-5-nitroaniline has limited solubility in water. Polar aprotic solvents such as dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) generally provide good solubility. Ethanol and dichloromethane are also commonly used depending on the downstream reaction requirements. Always test solubility on a small scale before preparing large stock solutions.

Can the nitro group of 2-Chloro-4-fluoro-5-nitroaniline be selectively reduced without affecting the halogen substituents?

Selective reduction of the nitro group is achievable using mild reducing systems such as iron powder in acetic acid (Baeyer-Villiger-type reduction conditions) or SnCl₂ in ethanol/HCl, which typically leave the C–Cl and C–F bonds intact under controlled conditions. Catalytic hydrogenation (Pd/C, H₂) can also reduce the nitro group but may risk hydrodehalogenation, particularly of the C–Cl bond, depending on pressure and catalyst loading. Reaction conditions should be carefully optimized and validated for each specific substrate and scale.

What are the main hazards associated with 2-Chloro-4-fluoro-5-nitroaniline and how should spills be managed?

As a halogenated aromatic amine bearing a nitro group, this compound is potentially toxic by inhalation, ingestion, and skin absorption, and is an irritant to skin, eyes, and respiratory tract. In case of a spill, evacuate unnecessary personnel, don full PPE, carefully collect the solid using inert absorbent material (e.g., dry sand or vermiculite), and transfer to a labeled hazardous waste container. Avoid generating dust. Clean the affected area with appropriate solvent followed by water. Dispose of all collected material according to local hazardous waste regulations.

Is 2-Chloro-4-fluoro-5-nitroaniline suitable for use as a pharmaceutical intermediate?

Yes, 2-Chloro-4-fluoro-5-nitroaniline is widely used as a building block in pharmaceutical synthesis, particularly for the preparation of fluorinated and halogenated heterocyclic scaffolds such as benzimidazoles and quinoxalines that appear in drug candidates. However, for GMP pharmaceutical manufacturing, the compound must meet appropriate purity and quality specifications; researchers should consult Aladdin Scientific for material grade options and available analytical data.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. 4th ed. Wiley-Interscience, 1992. (General reference for S_NAr reactions and aromatic amine chemistry.)
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry. 2nd ed. Oxford University Press, 2012. (Textbook-level coverage of nitro group reductions and aniline reactivity.)
3. Aladdin Scientific. Product Specification Sheet: 2-Chloro-4-fluoro-5-nitroaniline, SKU C768388. Aladdin Scientific, Shanghai. (Primary source for purity, physical data, and storage recommendations.)

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.