3-Bromo-2-Isopropoxypyridine: Handling & Synthesis Protocol

3-Bromo-2-isopropoxypyridine is a halogenated pyridine building block widely employed in medicinal and synthetic chemistry as a versatile electrophilic partner in metal-catalyzed cross-coupling and nucleophilic aromatic substitution reactions.

CAS Number

To be confirmed — see product datasheet (SKU B730337)

Molecular Formula

C8H10BrNO

Molecular Weight

216.08 g/mol

Appearance

Colorless to pale yellow liquid or solid (verify with CoA)

Storage Conditions

Store in a cool, dry, well-ventilated area; protect from light and moisture

Functional Groups

Aryl bromide, isopropoxy ether, pyridine nitrogen

Primary Application

Electrophilic building block in Suzuki, Negishi, and Buchwald-Hartwig couplings

Overview and Chemical Properties

3-Bromo-2-isopropoxypyridine (SKU: B730337) is a substituted pyridine featuring an aryl bromide at the 3-position and an isopropoxy ether at the 2-position. The electron-withdrawing pyridine nitrogen activates the ring toward nucleophilic aromatic substitution (SNAr), while the C–Br bond serves as a handle for transition-metal-catalyzed cross-coupling reactions such as Suzuki–Miyaura, Negishi, and Buchwald–Hartwig amination.

The isopropoxy group at the 2-position provides steric and electronic modulation of the ring, making this compound a valuable precursor in the synthesis of pharmaceutically relevant heterocycles and agrochemical intermediates. Researchers should consult the certificate of analysis (CoA) provided with each lot for confirmed purity, melting/boiling point, and spectroscopic data.

Safety and Handling Guidelines

Prior to use, consult the Safety Data Sheet (SDS) for 3-Bromo-2-isopropoxypyridine. As with most aryl bromides and alkoxy-substituted heteroaromatics, the following precautions are recommended:

• Personal Protective Equipment (PPE): Wear chemical-resistant gloves (nitrile recommended), a lab coat, and safety goggles. Use a face shield if splash risk is present.
• Ventilation: Handle in a well-ventilated fume hood to avoid inhalation of vapors or dust.
• Skin and Eye Contact: In case of contact, flush the affected area immediately with copious amounts of water for at least 15 minutes and seek medical attention.
• Waste Disposal: Dispose of all waste in accordance with local, regional, and national regulations for halogenated organic compounds.

Note: Specific GHS hazard classifications should be confirmed from the SDS supplied with SKU B730337.

Protocol: Suzuki–Miyaura Cross-Coupling

The following is a general protocol for Suzuki–Miyaura cross-coupling using 3-Bromo-2-isopropoxypyridine as the aryl halide electrophile. Optimize reagent ratios, catalyst loading, and conditions for your specific substrate.

1. Materials: 3-Bromo-2-isopropoxypyridine (1.0 equiv, SKU B730337), arylboronic acid or ester (1.2–1.5 equiv), Pd catalyst (e.g., Pd(PPh₃)₄ or Pd(dppf)Cl₂, 2–5 mol%), base (e.g., K₂CO₃ or Cs₂CO₃, 2–3 equiv), solvent (e.g., DMF/H₂O, dioxane/H₂O, or toluene/EtOH).
2. Setup: Charge a dry round-bottom flask or Schlenk tube with the palladium catalyst and ligand (if separate). Add the arylboronic partner, base, and solvent under inert atmosphere (N₂ or Ar).
3. Addition: Add 3-Bromo-2-isopropoxypyridine as a solution in the chosen solvent via syringe or cannula.
4. Reaction: Stir the mixture at 80–100 °C for 12–24 hours (or until TLC/LCMS indicates complete consumption of starting material). Monitor reaction progress regularly.
5. Workup: Cool to room temperature, dilute with ethyl acetate, and wash with saturated aqueous NH₄Cl, then brine. Dry the organic layer over MgSO₄ or Na₂SO₄, filter, and concentrate under reduced pressure.
6. Purification: Purify the crude product by column chromatography (silica gel, appropriate eluent system) or recrystallization as appropriate.

Disclaimer: These conditions are provided as a general starting point. Researchers should optimize and validate conditions for their specific applications. Reaction yields and selectivities are substrate-dependent.

Storage and Stability

To maintain the integrity and purity of 3-Bromo-2-isopropoxypyridine over time, adhere to the following storage recommendations:

• Store in a tightly sealed container in a cool (2–25 °C), dry, and well-ventilated location away from direct light and heat sources.
• Protect from moisture; the isopropoxy group may be susceptible to hydrolysis under prolonged exposure to strongly acidic or basic aqueous conditions.
• After each use, reseal the container under inert gas (N₂ or Ar) to minimize atmospheric exposure.
• Check the expiration date on the product label and re-verify purity by NMR or HPLC if the compound has been stored for an extended period.

Specific shelf-life data should be confirmed from the product datasheet or CoA for lot B730337.

Quality and Purity Considerations

Aladdin Scientific supplies 3-Bromo-2-isopropoxypyridine (SKU B730337) with a certificate of analysis (CoA) detailing lot-specific purity and analytical data. When selecting this reagent for sensitive synthetic workflows, researchers should consider:

• Purity Assessment: Verify purity by ¹H NMR and/or GC-MS or HPLC prior to use in demanding reactions such as asymmetric catalysis or pharmaceutical synthesis.
• Trace Metal Content: For reactions sensitive to trace metal impurities, request ICP-MS data or use additional purification steps such as passage through a short pad of activated charcoal or Celite.
• Water Content: If moisture is a concern for your reaction (e.g., organolithium or Grignard conditions), dry the reagent over molecular sieves before use.
• Lot-to-Lot Consistency: Always reference the CoA for the specific lot number received. Contact Aladdin Scientific technical support for any purity or specification queries.

Frequently asked questions

What cross-coupling reactions is 3-Bromo-2-isopropoxypyridine suitable for?

3-Bromo-2-isopropoxypyridine is well-suited for palladium-catalyzed Suzuki–Miyaura, Negishi, and Buchwald–Hartwig cross-coupling reactions owing to its reactive aryl C–Br bond. It may also participate in nucleophilic aromatic substitution (SNAr) given the electron-deficient nature of the pyridine ring activated by the ring nitrogen. Researchers should optimize catalyst, ligand, base, and solvent conditions empirically for their specific coupling partner.

How should 3-Bromo-2-isopropoxypyridine be stored to maintain its stability?

Store 3-Bromo-2-isopropoxypyridine in a tightly sealed container under inert atmosphere in a cool, dry, and well-ventilated area away from light and moisture. After each use, reseal under nitrogen or argon. Confirm specific storage temperature and shelf life from the certificate of analysis provided with lot B730337.

What safety precautions are required when handling 3-Bromo-2-isopropoxypyridine?

Always handle 3-Bromo-2-isopropoxypyridine in a well-ventilated fume hood wearing nitrile gloves, a lab coat, and safety goggles. Consult the Safety Data Sheet (SDS) provided with SKU B730337 for specific GHS hazard classifications, first-aid measures, and disposal instructions. Dispose of waste as halogenated organic material in compliance with applicable regulations.

Can the isopropoxy group of 3-Bromo-2-isopropoxypyridine be selectively cleaved or modified?

The isopropoxy ether at the 2-position of the pyridine ring can potentially be cleaved under strongly acidic or Lewis-acid-mediated conditions to reveal the corresponding pyridinol, or it may be exchanged via O-alkylation chemistry. Selectivity in the presence of the aryl bromide will depend on the specific conditions employed. Researchers are advised to consult the primary literature for analogous transformations and to verify that the C–Br bond remains intact under the chosen deprotection conditions.

References

1. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007
2. 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
3. Aladdin Scientific. Product Datasheet: 3-Bromo-2-isopropoxypyridine, SKU B730337. Aladdin Scientific, Shanghai.

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