5-(Bromomethyl)-2-methoxypyridine Hydrobromide: Lab Guide

5-(Bromomethyl)-2-methoxypyridine hydrobromide is a reactive benzylic bromide salt widely employed as a versatile alkylating building block in medicinal chemistry and heterocyclic synthesis.

CAS / SKU

SKU B1341177 (CAS to be confirmed by supplier)

Molecular Formula

C7H9BrN·O · HBr (free base: C7H8BrNO)

Functional Class

Benzylic alkyl bromide; pyridine derivative; hydrobromide salt

Primary Use

Electrophilic alkylating agent in N-, O-, S-, and C-alkylation reactions

Recommended Storage

Cool, dry, dark conditions; away from moisture and nucleophiles (specific temperature to be confirmed)

Salt Form Advantage

Hydrobromide salt improves handling stability compared with the free benzylic bromide

Chemical Identity and Properties

5-(Bromomethyl)-2-methoxypyridine hydrobromide (Aladdin SKU B1341177) is a pyridine-based benzylic bromide supplied as its hydrobromide salt. The parent heterocycle is a 2-methoxypyridine ring bearing a bromomethyl substituent at the 5-position. This structural arrangement places an electron-withdrawing pyridine nitrogen in conjugation with the benzylic carbon, significantly enhancing electrophilicity at the methylene site relative to purely carbocyclic benzylic bromides.

The hydrobromide salt form stabilises the compound during storage and transport by reducing the tendency of the free amine base (if present) to undergo self-alkylation or degradation. Researchers should confirm the exact molecular weight, melting point, and purity certificate directly from the Aladdin Scientific product datasheet, as these values are subject to lot-specific variation.

Synthetic Applications and Reactivity

As a reactive benzylic bromide, 5-(Bromomethyl)-2-methoxypyridine hydrobromide serves as a key electrophilic building block in a broad range of synthetic transformations. Common applications include:

• N-Alkylation: Quaternisation of amines, including preparation of N-benzyl amines and ammonium salts relevant to pharmacophore design.
• O-Alkylation: Etherification of phenols, alcohols, and other oxygen nucleophiles under mild base conditions.
• S-Alkylation: Thioether formation with thiols and thiolate anions.
• C-Alkylation: Coupling with stabilised carbanions such as malonates or active methylene compounds.
• Cross-coupling precursor: The benzylic bromide can be converted to organometallic species for palladium-catalysed coupling reactions, though this is less common than direct SN2 alkylation.

The 2-methoxy group on the pyridine ring modulates the electron density of the ring and may also participate in directing effects during further functionalisation. This makes the compound a valuable scaffold for fragment-based drug discovery and lead optimisation campaigns.

Handling, Safety, and Storage Guidelines

Benzylic bromide compounds are potent alkylating agents and should be treated as potential irritants and lachrymatory substances. The following precautions reflect general best practice for this reagent class; consult the official Safety Data Sheet (SDS) provided by Aladdin Scientific for lot-specific hazard information:

• Personal Protective Equipment (PPE): Wear chemically resistant gloves (nitrile or neoprene), safety goggles, and a laboratory coat. Work in a well-ventilated fume hood.
• Inhalation: Avoid breathing dust or vapours. Use respiratory protection if ventilation is insufficient.
• Skin and Eye Contact: Flush thoroughly with water for at least 15 minutes; seek medical attention for significant exposure.
• Storage: Store in a tightly sealed container under cool, dry, and dark conditions. Segregate from amines, alcohols, thiols, and strong bases to prevent premature reaction. Specific recommended temperature should be confirmed from the product label.
• Disposal: Dispose of in accordance with local and institutional regulations for halogenated organic waste.

Hydroscopic tendencies of the hydrobromide salt mean that exposure to atmospheric moisture should be minimised. Weigh and handle under inert atmosphere (nitrogen or argon) when high purity is critical.

Quality, Purity, and Procurement

Aladdin Scientific supplies 5-(Bromomethyl)-2-methoxypyridine hydrobromide under SKU B1341177. Researchers and procurement managers should request the following documentation when ordering:

• Certificate of Analysis (CoA): Confirms lot-specific purity (typically assessed by HPLC or NMR), appearance, and identity.
• Safety Data Sheet (SDS): Required for institutional chemical inventory, risk assessment, and regulatory compliance.
• Structural Confirmation: ¹H NMR and/or mass spectrometry data should be reviewed to verify compound identity before use in critical synthetic steps.

When evaluating purity specifications, consider that the hydrobromide salt content contributes to molecular weight; ensure that yield calculations in downstream reactions are based on the correct formula weight of the salt versus the free base, depending on the protocol employed.

For bulk quantities or custom specifications, contact Aladdin Scientific's technical sales team directly. Pricing, availability, and lead times are subject to change; refer to the current product listing for up-to-date information.

Frequently asked questions

What is the difference between the free base and the hydrobromide salt form of 5-(Bromomethyl)-2-methoxypyridine?

The hydrobromide salt is formed by protonation of the pyridine nitrogen with hydrobromic acid, resulting in improved solid-state stability and easier handling compared with the free base. In most synthetic protocols, the free base can be liberated in situ by treatment with an appropriate base such as triethylamine or potassium carbonate before the alkylation step.

How should I activate or deprotonate the hydrobromide salt for use in alkylation reactions?

Add 1–1.2 equivalents of an inorganic base (e.g., K₂CO₃, Cs₂CO₃) or an organic base (e.g., Et₃N, DIPEA) to the reaction mixture prior to or concurrent with adding the nucleophile. This neutralises the hydrobromide counterion and generates the reactive benzylic bromide in situ. The choice of base and solvent should be optimised based on the nucleophile and reaction conditions. Specific equivalents and conditions should be validated experimentally.

What solvents are recommended for reactions using this compound?

Polar aprotic solvents such as DMF, DMSO, acetonitrile, or acetone are commonly used for SN2 alkylation reactions involving benzylic bromides, as they solvate cations well without quenching the electrophile. THF or DCM may be suitable for certain coupling reactions. Protic solvents should generally be avoided as they may hydrolyse the benzylic bromide or compete with the intended nucleophile. Solvent selection should always be confirmed by consulting the specific reaction literature or performing preliminary experiments.

How should I store this reagent to maintain its integrity?

Store the compound in a tightly sealed vial under cool, dry, and dark conditions, away from moisture, amines, and nucleophilic species. For long-term storage, an inert atmosphere (nitrogen or argon) is recommended. Always refer to the Aladdin Scientific product label and SDS for the most authoritative storage instructions specific to this lot.

References

1. March, J.; Smith, M. B. March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 7th ed.; Wiley: Hoboken, NJ, 2013. (General reference for SN2 alkylation and benzylic bromide reactivity.)
2. Aladdin Scientific. Product Datasheet and Certificate of Analysis for 5-(Bromomethyl)-2-methoxypyridine hydrobromide, SKU B1341177. (Consult current lot CoA for specific purity and physicochemical data.)

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