5-Bromo-2-methyl-3-nitropyridine: Properties, Uses & FAQs

5-Bromo-2-methyl-3-nitropyridine is a halogenated, nitro-substituted pyridine building block widely used as a versatile intermediate in pharmaceutical synthesis and medicinal chemistry research.

Chemical Name

5-Bromo-2-methyl-3-nitropyridine

CAS Number

6966-52-5

Molecular Formula

C6H5BrN2O2

Molecular Weight

217.02 g/mol

Appearance

Pale yellow to yellow crystalline solid

Recommended Storage

Cool, dry place; away from light and moisture

Key Functional Groups

Bromo, nitro, methyl substituents on pyridine ring

Aladdin SKU

B139418

What Is 5-Bromo-2-methyl-3-nitropyridine?

5-Bromo-2-methyl-3-nitropyridine (CAS 6966-52-5) is a substituted pyridine heterocycle bearing three key functional groups: a bromine atom at the 5-position, a methyl group at the 2-position, and a nitro group at the 3-position. This combination of substituents makes it a highly reactive and versatile scaffold for organic synthesis.

The pyridine ring system, combined with the electron-withdrawing nitro group and the halogen handle provided by the bromine atom, enables a broad range of chemical transformations. Researchers in pharmaceutical, agrochemical, and materials chemistry routinely employ this compound as a starting material or intermediate in the construction of more complex molecules.

Key Chemical Properties and Handling

5-Bromo-2-methyl-3-nitropyridine is typically obtained as a pale yellow to yellow crystalline solid at room temperature. The nitro group at the 3-position is strongly electron-withdrawing, activating the ring toward nucleophilic aromatic substitution (SNAr) while also influencing the reactivity of the adjacent bromine toward metal-catalyzed cross-coupling reactions such as Suzuki, Negishi, and Buchwald-Hartwig couplings.

When handling this compound, standard laboratory precautions for nitro-aromatic compounds should be observed. These include wearing appropriate personal protective equipment (gloves, safety glasses, lab coat), working in a well-ventilated fume hood, and avoiding ignition sources, as nitro compounds can be sensitive to heat and shock in concentrated or impure forms. The compound should be stored in a tightly sealed container in a cool, dry location away from direct light and moisture to preserve stability.

Dissolution is generally achieved in common polar aprotic solvents such as DMF, DMSO, acetonitrile, and dichloromethane. Aqueous solubility is limited, which is typical for halogenated nitroheterocycles of this class.

Synthetic Applications in Pharmaceutical and Medicinal Chemistry

The primary value of 5-Bromo-2-methyl-3-nitropyridine in research lies in its role as a multifunctional building block. The C–Br bond provides a reactive site for transition-metal-catalyzed cross-coupling reactions, enabling the introduction of aryl, heteroaryl, vinyl, or amino groups to diversify the pyridine scaffold. Common reactions exploited include:

• Suzuki-Miyaura coupling: attachment of boronic acids or esters to furnish biaryl or heteroaryl systems.
• Buchwald-Hartwig amination: conversion of the C–Br bond to C–N bonds for the synthesis of aminopyridine derivatives.
• Nucleophilic aromatic substitution (SNAr): the activated nitro group facilitates displacement reactions with suitable nucleophiles.
• Reduction of the nitro group: catalytic hydrogenation or chemical reduction (e.g., Fe/AcOH, SnCl2) converts the nitro group to an amine, opening access to 3-aminopyridine intermediates useful in drug discovery.

The 2-methyl group can be further functionalized through radical bromination or oxidation to provide aldehyde or carboxylic acid handles for additional elaboration. These orthogonal reactive sites make this compound particularly attractive for library synthesis and lead optimization in drug discovery programs.

Purity, Specifications and Quality Considerations

For research applications, the purity of 5-Bromo-2-methyl-3-nitropyridine is a critical parameter, particularly when the compound is used in sensitive catalytic reactions or as a reference standard. Aladdin Scientific supplies this compound (SKU: B139418) with purity specifications intended to meet the demands of laboratory-scale synthesis. Researchers should consult the product's Certificate of Analysis (CoA) for lot-specific purity data, typically determined by HPLC or GC methods.

Impurities commonly associated with halogenated nitropyridines may include regioisomeric byproducts from the nitration or bromination steps during manufacture. It is advisable to verify purity by NMR or HPLC prior to use in reactions where impurity levels could affect yield or selectivity.

For long-term storage, keeping the material under inert atmosphere (nitrogen or argon) and refrigerated conditions can further minimize degradation. Contact Aladdin Scientific customer service for information on available pack sizes, bulk quantities, and custom specifications.

Safety, Regulatory and Shipping Information

5-Bromo-2-methyl-3-nitropyridine should be treated as a potentially hazardous chemical in accordance with its Safety Data Sheet (SDS). As a nitroaromatic compound, it may present irritant or sensitization hazards upon skin or eye contact, and inhalation of dust should be avoided. Appropriate GHS hazard classifications should be consulted before use.

From a regulatory perspective, this compound is not currently listed as a controlled substance under major international frameworks, but users are responsible for compliance with local regulations governing the purchase, storage, and disposal of nitroaromatic compounds. Waste disposal should follow institutional and local environmental guidelines.

For shipping, the compound is generally transported as a standard chemical reagent. However, customers outside the domestic region should confirm import regulations and any applicable export control requirements with Aladdin Scientific's logistics team prior to ordering. Aladdin Scientific provides SDS documentation upon request and as part of standard order fulfillment.

Frequently asked questions

What is the CAS number for 5-Bromo-2-methyl-3-nitropyridine?

The CAS registry number for 5-Bromo-2-methyl-3-nitropyridine is 6966-52-5. This number uniquely identifies the compound and can be used to verify identity against the Certificate of Analysis (CoA) and Safety Data Sheet (SDS) supplied with each lot.

What solvents are suitable for dissolving 5-Bromo-2-methyl-3-nitropyridine?

5-Bromo-2-methyl-3-nitropyridine dissolves well in common polar aprotic solvents including DMF, DMSO, acetonitrile, and dichloromethane. Aqueous solubility is generally low, as is typical for halogenated nitroheterocycles. Solvent selection should be guided by the specific reaction conditions intended.

How should 5-Bromo-2-methyl-3-nitropyridine be stored to maintain stability?

The compound should be stored in a tightly sealed container in a cool, dry place away from direct light and moisture. For extended storage periods, keeping the material under an inert atmosphere such as nitrogen or argon and at refrigerated temperatures is recommended to minimize the risk of degradation or moisture uptake.

What cross-coupling reactions can be performed using 5-Bromo-2-methyl-3-nitropyridine?

The C–Br bond in 5-Bromo-2-methyl-3-nitropyridine makes it suitable for a range of palladium- and nickel-catalyzed cross-coupling reactions, including Suzuki-Miyaura coupling with boronic acids, Buchwald-Hartwig amination for C–N bond formation, and Negishi coupling with organozinc reagents. The electron-withdrawing nitro group can further facilitate nucleophilic aromatic substitution under appropriate conditions.

Can the nitro group in 5-Bromo-2-methyl-3-nitropyridine be selectively reduced to an amine?

Yes, the nitro group can be selectively reduced to an amine using standard methods such as catalytic hydrogenation (H2/Pd-C) or chemical reduction reagents including iron in acetic acid or tin(II) chloride in ethanol. The resulting 3-amino-5-bromo-2-methylpyridine intermediate retains the reactive C–Br bond for further derivatization and is a valuable intermediate in drug discovery.

What purity grade is available for Aladdin's 5-Bromo-2-methyl-3-nitropyridine (SKU B139418)?

Aladdin Scientific offers 5-Bromo-2-methyl-3-nitropyridine under SKU B139418 for research use. Specific purity values and analytical data are provided in the lot-specific Certificate of Analysis (CoA), available upon request or via the product page. Customers are advised to review the CoA before use in sensitive synthetic applications.

References

1. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. General reference for nucleophilic aromatic substitution and cross-coupling reactions.
2. 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
3. Aladdin Scientific Product Page: 5-Bromo-2-methyl-3-nitropyridine, SKU B139418. Aladdin Scientific Co., Ltd.

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