4-Bromo-2,3-Difluorobenzaldehyde: FAQs & Technical Guide

4-Bromo-2,3-difluorobenzaldehyde is a multifunctionally substituted aromatic aldehyde bearing both halogen and fluorine substituents that make it a versatile building block for pharmaceutical and agrochemical synthesis.

Chemical Name

4-Bromo-2,3-difluorobenzaldehyde

Molecular Formula

C7H3BrF2O

Molecular Weight

221.00 g/mol

Aladdin SKU

B194378

Functional Groups

Aldehyde (–CHO), two fluorines (C2, C3), one bromine (C4)

Primary Use

Synthetic intermediate in medicinal and organofluorine chemistry

What Is 4-Bromo-2,3-Difluorobenzaldehyde?

4-Bromo-2,3-difluorobenzaldehyde (Aladdin SKU: B194378) is an aromatic aldehyde in which the benzaldehyde core carries a bromine substituent at the para position (C4) and fluorine atoms at the ortho and meta positions (C2 and C3) relative to the aldehyde group. The simultaneous presence of an aldehyde, a C–Br bond, and two C–F bonds in a single compact molecule makes this compound particularly attractive as a multifunctional building block.

The electron-withdrawing nature of the fluorine atoms activates the ring toward nucleophilic aromatic substitution and modifies the electrophilicity of the aldehyde carbonyl, while the bromine atom provides a reliable handle for transition-metal-catalyzed cross-coupling reactions such as Suzuki–Miyaura, Buchwald–Hartwig, and Sonogashira couplings.

Handling, Storage, and Safety

Storage: Store 4-Bromo-2,3-difluorobenzaldehyde in a tightly sealed container under cool, dry, and well-ventilated conditions, away from heat sources and incompatible oxidizing agents. Refrigerated storage (2–8 °C) is recommended to minimize slow decomposition of the aldehyde functionality over time.

Handling: Wear appropriate personal protective equipment including chemical-resistant gloves, safety goggles, and a laboratory coat. Work in a fume hood to avoid inhalation of dust or vapors. Aromatic aldehydes may cause skin and eye irritation; consult the Safety Data Sheet (SDS) supplied with each shipment before use.

Disposal: Dispose of waste material in accordance with local, regional, and national regulations governing halogenated organic compounds. Do not pour down the drain.

Applications in Organic Synthesis

The three electrophilic sites in 4-Bromo-2,3-difluorobenzaldehyde—the aldehyde carbon, the ipso carbon bearing bromine, and the ring positions activated by the flanking fluorines—enable diverse synthetic transformations:

• Cross-coupling reactions: The C4–Br bond undergoes palladium- or nickel-catalyzed coupling with boronic acids, amines, alkynes, and organozinc reagents to install aryl, heteroaryl, vinyl, or amino groups.
• Nucleophilic aromatic substitution (SNAr): Fluorine atoms at C2 and C3, activated by the electron-withdrawing aldehyde and the adjacent halogens, can be displaced by O-, N-, or S-nucleophiles under mild conditions.
• Reductive amination: The aldehyde reacts with primary or secondary amines in the presence of a reducing agent (e.g., NaBH3CN or NaBH(OAc)3) to give secondary or tertiary benzylamine derivatives.
• Condensation reactions: The aldehyde participates in Knoevenagel, Wittig, Horner–Wadsworth–Emmons, and similar reactions to extend the carbon framework.

These features collectively position this compound as a key intermediate in the construction of fluorinated drug candidates, agrochemicals, and functional materials.

Purity, Grade, and Quality Specifications

Aladdin Scientific supplies 4-Bromo-2,3-difluorobenzaldehyde (SKU: B194378) as a research-grade reagent. Typical quality control testing may include:

• Purity determination by GC or HPLC with an area-normalization method.
• Identity confirmation by 1H NMR and/or HRMS to verify the molecular formula C7H3BrF2O and characteristic aldehyde proton signal (δ ≈ 10 ppm in CDCl3).
• Appearance as a white to off-white crystalline solid or pale yellow solid at room temperature.

A Certificate of Analysis (CoA) specifying lot-specific purity and analytical data is available on request or via the Aladdin website for each production lot. Contact Aladdin customer service if the CoA is not included with your shipment.

Ordering, Shipping, and Returns

Ordering: 4-Bromo-2,3-difluorobenzaldehyde (SKU: B194378) can be ordered directly through the Aladdin Scientific website or by contacting our sales team. Bulk and custom quantities may be available upon inquiry.

Shipping: The compound is shipped as a solid at ambient temperature in a sealed, labeled container in accordance with applicable transport regulations for non-hazardous or mildly hazardous solids. Expedited shipping options are available; please specify your requirements at the time of order.

Returns and refunds: If the product does not meet the specifications stated on the CoA, or if damage occurred during transit, please contact Aladdin customer service within the timeframe specified in our returns policy. Provide the lot number, order number, and a description of the issue. Do not return chemicals without prior authorization.

Frequently asked questions

What is the CAS number for 4-Bromo-2,3-difluorobenzaldehyde?

The CAS registry number commonly associated with 4-Bromo-2,3-difluorobenzaldehyde is 170282-48-1. Please verify this against the Certificate of Analysis supplied with your specific lot, as Aladdin's product page and CoA are the authoritative references for the material you receive.

How should I store 4-Bromo-2,3-difluorobenzaldehyde to maximize shelf life?

Store the compound in a tightly sealed container at 2–8 °C, away from light, moisture, and oxidizing agents. Under these conditions the aldehyde functionality is preserved and discoloration or oligomerization is minimized. Re-seal the container promptly after each use and allow cold material to equilibrate to room temperature before opening to avoid moisture condensation.

Which cross-coupling reactions are compatible with the C–Br bond in this compound?

The aryl C–Br bond at the para position is compatible with a wide range of palladium-catalyzed cross-coupling reactions, including Suzuki–Miyaura (with aryl or heteroaryl boronic acids), Buchwald–Hartwig (amination with primary or secondary amines), Sonogashira (with terminal alkynes), and Negishi couplings (with organozinc reagents). Nickel catalysis is also applicable for certain coupling partners. Standard reaction conditions for aryl bromides apply; the electron-withdrawing fluorine atoms at C2 and C3 generally accelerate oxidative addition to the palladium center.

Can the fluorine atoms in 4-Bromo-2,3-difluorobenzaldehyde be selectively displaced?

Yes. The fluorine atoms at C2 and C3 are activated toward nucleophilic aromatic substitution (SNAr) by the combined electron-withdrawing effects of the aldehyde group and the adjacent halogens. Regioselectivity between the two fluorines depends on the nature of the nucleophile and reaction conditions; C2 (ortho to CHO) is typically more electrophilically activated. Careful optimization of temperature, solvent, and nucleophile stoichiometry is recommended to achieve selective mono-substitution.

How do I obtain a Certificate of Analysis (CoA) for my lot of B194378?

A lot-specific Certificate of Analysis can be downloaded from the Aladdin Scientific product page for B194378 by entering your lot number in the CoA lookup tool. If you cannot locate it online, contact Aladdin customer service with your order number and lot number and the document will be provided promptly.

Is 4-Bromo-2,3-difluorobenzaldehyde available in bulk or custom quantities?

Aladdin Scientific can accommodate bulk and custom quantity requests for B194378. Please contact our sales or custom-synthesis team with your quantity requirements, timeline, and purity specifications, and we will provide a quotation.

References

1. Fluorine in Medicinal Chemistry and Chemical Biology, ed. I. Ojima, Wiley-Blackwell, 2009. General reference on the role of fluorine substituents in drug discovery and SNAr reactivity.
2. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007
3. Aladdin Scientific Product Page: 4-Bromo-2,3-difluorobenzaldehyde, SKU B194378. Aladdin Scientific, accessed 2024.

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