6-Bromo-3-chloro-2-methylpyridine: Properties & Lab Guide

6-Bromo-3-chloro-2-methylpyridine is a di-halogenated methylpyridine building block widely employed in medicinal chemistry and materials science as a versatile intermediate for cross-coupling and nucleophilic substitution reactions.

Chemical Name

6-Bromo-3-chloro-2-methylpyridine

SKU

B195989

Molecular Formula

C6H5BrClN

Molecular Weight

206.47 g/mol

CAS Number

405230-96-8

Functional Groups

Aryl bromide, aryl chloride, methyl substituent on pyridine ring

Primary Applications

Suzuki, Negishi, and Buchwald-Hartwig cross-coupling; nucleophilic aromatic substitution; pharmaceutical intermediate synthesis

Chemical Identity and Physical Properties

6-Bromo-3-chloro-2-methylpyridine (CAS 405230-96-8, SKU B195989) is a substituted pyridine bearing two halogen substituents—bromine at the 6-position and chlorine at the 3-position—together with a methyl group at the 2-position. Its molecular formula is C₆H₅BrClN with a molecular weight of approximately 206.47 g/mol.

The compound typically presents as a white to off-white solid or crystalline powder at ambient temperature. The differential reactivity of the C–Br and C–Cl bonds is a defining chemical feature: the C–Br bond at the 6-position is substantially more reactive toward palladium-catalysed cross-coupling reactions than the C–Cl bond at the 3-position, enabling sequential, chemoselective functionalisation. The methyl group at the 2-position can influence both the electronic character of the ring and the steric environment around adjacent reaction centres.

Note: Precise physical constants (melting point, boiling point, density, solubility) should be confirmed from the Certificate of Analysis supplied with each lot.

Synthetic Applications and Reactivity

The orthogonal reactivity of the two carbon–halogen bonds makes 6-Bromo-3-chloro-2-methylpyridine a highly strategic building block in medicinal chemistry, agrochemistry, and materials science.

Palladium-catalysed cross-coupling: The aryl bromide at C-6 undergoes selective Suzuki–Miyaura, Negishi, and Stille coupling reactions under standard conditions, allowing introduction of aryl, heteroaryl, alkenyl, or alkyl groups before—or independently of—manipulation of the C–Cl bond. Buchwald–Hartwig amination can also be applied to install nitrogen-containing fragments.

Sequential halogen utilisation: After selective cross-coupling at C-6, the remaining C–Cl bond at C-3 can be engaged in subsequent palladium-catalysed reactions using more active catalyst systems, or in copper-mediated Ullmann-type couplings, enabling the construction of complex di-substituted pyridine architectures in a controlled stepwise manner.

Nucleophilic aromatic substitution (SNAr): The electron-deficient pyridine ring, activated by the nitrogen atom and the halogen substituents, can participate in SNAr reactions with suitable nucleophiles (amines, alkoxides, thiolates) at the halogen-bearing positions, providing additional routes to functionalised products.

Pharmaceutical intermediates: Di-halogenated methylpyridines are frequently employed as cores or fragments in the synthesis of kinase inhibitors, ion-channel modulators, and other bioactive small molecules where the pyridine nitrogen provides a hydrogen-bond acceptor motif.

Handling, Safety, and Storage Guidelines

Personal Protective Equipment (PPE): When handling 6-Bromo-3-chloro-2-methylpyridine, wear appropriate chemical-resistant gloves (nitrile recommended), laboratory coat, and safety glasses or goggles. Avoid inhalation of dust or vapours; work in a well-ventilated fume hood.

Storage: Store the compound in a tightly sealed container in a cool, dry, well-ventilated area away from incompatible materials such as strong oxidisers, strong acids, and strong bases. Recommended storage temperature is typically 2–8 °C or as specified on the product label and Certificate of Analysis. Protect from light and moisture to prevent decomposition or discolouration.

Spill and disposal: In the event of a spill, sweep up solid material and place into a labelled waste container for disposal in accordance with local, regional, and national regulations governing halogenated organic waste. Do not flush to drain.

Safety data: Consult the Safety Data Sheet (SDS) for this product before use. The SDS provides authoritative information on hazard classification, first-aid measures, fire-fighting procedures, and regulatory information. Specific GHS hazard classifications should be taken directly from the current SDS associated with SKU B195989.

Review flag: Specific GHS hazard codes, H-statements, and P-statements for this compound have not been independently verified in this document and must be sourced from the official SDS.

Quality, Purity, and Procurement Considerations

Purity specifications: For most synthetic chemistry applications, a purity of ≥97% (GC or HPLC) is recommended to minimise the impact of impurities on reaction yields and product purity. Aladdin Scientific provides a Certificate of Analysis (CoA) with each lot of B195989, detailing purity, appearance, and identity confirmation (typically by NMR and/or GC-MS).

Lot-to-lot consistency: Researchers conducting reproducibility-sensitive studies should record the lot number and refer to the lot-specific CoA when reporting experimental data.

Packaging and quantity: The compound is typically available in multiple pack sizes to suit both exploratory and scale-up synthetic needs. Contact Aladdin Scientific or consult the product listing for current available quantities and pricing.

Ordering: Reference SKU B195989 when placing orders to ensure correct product identification. Bulk or custom quantity enquiries can be directed to the Aladdin Scientific sales team.

Frequently asked questions

What makes 6-Bromo-3-chloro-2-methylpyridine useful for sequential cross-coupling reactions?

The compound carries two halogen substituents with inherently different reactivities: the aryl C–Br bond at the 6-position reacts much faster with palladium catalysts under typical cross-coupling conditions than the aryl C–Cl bond at the 3-position. This differential reactivity allows chemists to selectively functionalise the C-6 position first, and then engage the C-3 chloride in a subsequent step using more activating catalyst systems, enabling the controlled construction of complex, asymmetrically di-substituted pyridine targets.

How should 6-Bromo-3-chloro-2-methylpyridine (B195989) be stored to maintain stability?

The compound should be stored in a tightly sealed container at 2–8 °C (or as specified on the product label and Certificate of Analysis), in a cool, dry, well-ventilated area protected from light and moisture. Exposure to moisture, strong oxidisers, or prolonged light can lead to degradation or discolouration. Always consult the current SDS and CoA for lot-specific storage instructions.

Which reaction types are compatible with 6-Bromo-3-chloro-2-methylpyridine as a starting material?

6-Bromo-3-chloro-2-methylpyridine is compatible with palladium-catalysed cross-coupling reactions (Suzuki–Miyaura, Negishi, Stille, Buchwald–Hartwig), copper-mediated Ullmann-type couplings, and nucleophilic aromatic substitution (SNAr) with amines, alkoxides, and thiolates. The selective reactivity of the C–Br versus C–Cl bond allows stepwise multi-functionalisation strategies.

How do I confirm the identity and purity of the received compound?

Each lot of B195989 from Aladdin Scientific is accompanied by a Certificate of Analysis (CoA) that includes purity data (typically by GC or HPLC), appearance description, and identity confirmation (commonly by NMR and/or GC-MS). Verify that the lot number on the CoA matches your shipment label before use.

References

1. General reference for differential reactivity of aryl bromides versus aryl chlorides in palladium-catalysed cross-coupling: Johansson Seechurn, C. C. C.; Kitching, M. O.; Colacot, T. J.; Snieckus, V. Palladium-Catalyzed Cross-Coupling: A Historical Contextual Perspective to the 2010 Nobel Prize. Angew. Chem. Int. Ed. 2012, 51, 5062–5085. doi:10.1002/anie.201107017
2. Aladdin Scientific Product Page and Certificate of Analysis for 6-Bromo-3-chloro-2-methylpyridine, SKU B195989. Aladdin Scientific (accessed 2024).

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