4-(Bromomethyl)-2-chlorobenzonitrile: Properties & Applications

4-(Bromomethyl)-2-chlorobenzonitrile is a bifunctional aromatic building block bearing both a reactive benzyl bromide and an electron-withdrawing nitrile group, making it a versatile electrophilic intermediate widely used in medicinal and synthetic organic chemistry.

Molecular Formula

C8H5BrClN

Molecular Weight

230.49 g/mol

Key Functional Groups

Benzyl bromide (–CH2Br), nitrile (–CN), aryl chloride (Ar–Cl)

Primary Role in Synthesis

Electrophilic alkylating agent and multifunctional building block

Typical Storage Conditions

Cool, dry place; away from moisture and light; sealed container

Aladdin Scientific SKU

C730735

Chemical Structure and Physical Properties

4-(Bromomethyl)-2-chlorobenzonitrile is an aromatic compound featuring a benzene ring substituted at the 2-position with a chlorine atom, at the 4-position with a bromomethyl (–CH₂Br) group, and bearing a nitrile (–CN) group at the 1-position. This combination of substituents creates a molecule with distinct electronic and reactivity characteristics.

The nitrile group is a strong electron-withdrawing substituent that reduces electron density across the aromatic ring, while the ortho-chlorine further modulates the electronic environment. The benzylic bromide is the primary site of reactivity, exhibiting high susceptibility toward nucleophilic substitution (S_N2) reactions due to both the benzylic activation and the electron-deficient ring.

Typical physical properties include a solid state at room temperature. Exact melting point and precise solubility data should be confirmed from the certificate of analysis (CoA) supplied with each lot. The compound is generally soluble in common polar aprotic solvents such as DMF, DMSO, and acetonitrile, as well as in halogenated solvents such as dichloromethane.

Synthetic Applications and Reactivity

The principal synthetic utility of 4-(Bromomethyl)-2-chlorobenzonitrile derives from the highly reactive benzyl bromide moiety, which participates efficiently in a broad range of reactions:

• N-Alkylation: Reaction with primary and secondary amines, nitrogen heterocycles, or sulfonamides to introduce the 2-chloro-4-cyanobenzyl group onto nitrogen nucleophiles. This transformation is frequently employed in the synthesis of pharmacologically active compounds.
• O-Alkylation: Reaction with phenols, alcohols, or carboxylate salts to form benzyl ethers or esters, useful in protecting-group strategies and in the assembly of ether-containing drug scaffolds.
• C-Alkylation: Use with stabilized carbanions (malonates, active methylene compounds) to extend carbon frameworks.
• Cross-Coupling: The aryl chloride at the 2-position provides an additional handle for transition-metal-catalyzed cross-coupling reactions (e.g., Suzuki, Buchwald–Hartwig amination), enabling further diversification of the molecular scaffold.
• Nitrile Transformation: The –CN group can be hydrolyzed to a carboxylic acid, reduced to an amine, or converted to a tetrazole, providing additional points of diversification for medicinal chemistry programs.

These multiple reactive sites make this compound a genuinely multifunctional building block suitable for library synthesis and lead optimization campaigns.

Handling, Safety, and Storage Guidelines

As with all benzyl bromide-containing compounds, 4-(Bromomethyl)-2-chlorobenzonitrile should be handled with appropriate laboratory precautions:

• Personal Protective Equipment (PPE): Wear chemical-resistant gloves, lab coat, and safety goggles. The compound may be a lachrymator or irritant due to the benzyl bromide functionality; operations should be conducted in a well-ventilated fume hood.
• Skin and Eye Contact: Avoid direct contact. In case of skin contact, wash thoroughly with soap and water. In case of eye contact, rinse immediately with water and seek medical attention.
• Inhalation: Avoid breathing dust or vapors. Use appropriate respiratory protection if ventilation is insufficient.
• Storage: Store in a tightly sealed container in a cool, dry, well-ventilated location away from moisture, light, heat sources, and incompatible materials such as strong bases, strong nucleophiles, and oxidizing agents.
• Disposal: Dispose of in accordance with local regulations for halogenated organic waste.

Note: Always consult the Safety Data Sheet (SDS) provided by Aladdin Scientific for complete hazard information before use.

Purity, Quality, and Regulatory Considerations

For reliable synthetic outcomes, the purity of 4-(Bromomethyl)-2-chlorobenzonitrile is a critical parameter. Impurities such as the corresponding benzyl alcohol (hydrolysis product), debrominated toluene derivative, or bis-alkylation byproducts can negatively affect reaction selectivity and yield.

Aladdin Scientific supplies this compound with a Certificate of Analysis (CoA) that specifies purity (typically assessed by GC or HPLC), appearance, and other quality parameters on a per-lot basis. Researchers should verify the CoA upon receipt and store the reagent appropriately to maintain integrity over time.

From a regulatory standpoint, benzyl bromide derivatives may be subject to local chemical inventory and transport regulations. Procurement teams should verify applicable regulations in their jurisdiction prior to ordering. This compound is intended for research use only and is not approved for pharmaceutical, food, or diagnostic applications.

Frequently asked questions

What nucleophiles react efficiently with 4-(Bromomethyl)-2-chlorobenzonitrile?

The reactive benzyl bromide group undergoes efficient Sₙ2 reactions with a wide range of nucleophiles including primary and secondary amines, phenols, alcohols, carboxylates, thiolates, and stabilized carbanions such as malonates. The electron-withdrawing nitrile and chloro groups further activate the benzylic position, enhancing reactivity toward nucleophilic displacement.

Can the aryl chloride in this compound be used in cross-coupling reactions?

Yes. The aryl chloride at the 2-position is a competent partner in transition-metal-catalyzed cross-coupling reactions, including Suzuki–Miyaura coupling with boronic acids and Buchwald–Hartwig amination with amines, particularly when using modern palladium catalysts with bulky phosphine ligands optimized for aryl chloride activation. This provides an additional dimension of structural diversification beyond the benzyl bromide reactivity.

How should I handle the compound to minimize hydrolysis of the benzyl bromide?

To minimize hydrolysis, store the compound in a tightly sealed container under dry conditions and avoid prolonged exposure to moisture or protic solvents. When preparing solutions, use freshly dried, anhydrous solvents. Weighing operations should be performed quickly under low-humidity conditions or in a glovebox if the compound is particularly moisture-sensitive. Refer to the SDS and CoA for specific guidance.

Is 4-(Bromomethyl)-2-chlorobenzonitrile suitable for use in automated synthesis or high-throughput screening workflows?

Yes, the compound is well-suited for automated synthesis and high-throughput library generation due to its clean and predictable reactivity at the benzyl bromide position under mild conditions. It is typically soluble in DMSO and other common HTS-compatible solvents at working concentrations. Researchers should confirm solubility and stability under their specific assay conditions prior to large-scale library synthesis.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (General reference for Sₙ2 reactions of benzyl halides and nucleophilic aromatic substitution.)
2. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007
3. Hartwig, J. F. Evolution of a Fourth Generation Catalyst for the Amination and Thioetherification of Aryl Halides. Acc. Chem. Res. 2008, 41, 1534–1544. doi:10.1021/ar800098p
4. Aladdin Scientific Product Page: 4-(Bromomethyl)-2-chlorobenzonitrile, SKU C730735. Aladdin Scientific, Shanghai. (Product specifications and CoA available on request.)

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