Chemical Identity and Physicochemical Properties

2-Bromo-5-chloro-4-iodopyridine (SKU: B692893) is a polyhalogenated pyridine derivative bearing three distinct halogen substituents on the pyridine ring: bromine at the 2-position, chlorine at the 5-position, and iodine at the 4-position. Its molecular formula is C₅H₂BrClIN, and the compound belongs to the broader class of halopyridines widely employed in synthetic chemistry.

The presence of three electronegative halogens on the electron-deficient pyridine ring significantly influences its reactivity and physical properties. The compound is typically a solid at room temperature. The differential reactivity of C–I, C–Br, and C–Cl bonds toward transition-metal-catalyzed coupling reactions is the defining feature that makes this compound particularly valuable as a synthetic intermediate. C–I bonds are generally the most reactive toward oxidative addition, followed by C–Br, then C–Cl, enabling sequential, chemoselective functionalization.

Note: Specific melting point, boiling point, and exact molecular weight values were not confirmed in the source material and should be verified against the product certificate of analysis (CoA).

Synthetic Applications and Reaction Selectivity

The primary value of 2-Bromo-5-chloro-4-iodopyridine lies in its ability to serve as a platform for sequential, regioselective cross-coupling reactions. Because the three halogens differ substantially in their reactivity toward palladium- and nickel-catalyzed reactions, chemists can selectively functionalize each position in a controlled order.

Selective Functionalization Strategy:

• Step 1 — C–I bond: The C–I bond at the 4-position is typically engaged first using standard Suzuki–Miyaura, Sonogashira, Negishi, or Stille coupling conditions, often at mild temperatures and with low catalyst loadings.
• Step 2 — C–Br bond: After C–I functionalization, the C–Br bond at the 2-position can be selectively addressed under more forcing conditions or with appropriate catalyst systems.
• Step 3 — C–Cl bond: The C–Cl bond at the 5-position, being least reactive toward palladium catalysis under standard conditions, is reserved for final functionalization or for nucleophilic aromatic substitution (SNAr) reactions facilitated by the electron-deficient pyridine ring.

This compound finds application as a key building block in the synthesis of pharmaceutical candidates, agrochemical intermediates, and functional materials incorporating the pyridine scaffold. The halogen handles also allow for directed metalation and further elaboration via organolithium or Grignard chemistry.

Review flag: Specific literature examples of this exact compound in named reactions should be verified and cited.

Safe Handling, Storage, and Disposal

As with all organohalide reagents, appropriate safety precautions must be observed when handling 2-Bromo-5-chloro-4-iodopyridine. The following general guidelines apply; always consult the current Safety Data Sheet (SDS) for this specific compound before use.

Personal Protective Equipment (PPE): Wear appropriate chemical-resistant gloves (e.g., nitrile), laboratory coat, and eye protection (safety goggles). Where dust generation is possible, use respiratory protection.

Handling: Work in a well-ventilated laboratory or fume hood. Avoid inhalation of dust or vapors, skin contact, and ingestion. Minimize exposure time.

Storage: Store in a tightly sealed container in a cool, dry, well-ventilated area, away from moisture, heat sources, oxidizers, and strong bases. Recommended storage temperature and specific hazard classifications should be confirmed on the product SDS and CoA.

Disposal: Dispose of as halogenated organic waste in accordance with institutional, local, and national regulations. Do not pour down drains or discard with general laboratory waste.

Review flag: Specific GHS hazard codes, H-statements, P-statements, flash point, and LD₅₀ values were not available in the source material and must be sourced from the official SDS for B692893.

Quality Specifications and Ordering Information

Aladdin Scientific supplies 2-Bromo-5-chloro-4-iodopyridine under SKU B692893. Researchers should request the Certificate of Analysis (CoA) for the specific lot number received to confirm purity, appearance, and analytical data including NMR and HPLC or GC purity.

Typical quality checks for this class of compound include:

• Purity assessment by GC or HPLC
• Identity confirmation by ¹H NMR and/or ¹³C NMR
• Appearance (typically off-white to pale solid — confirm on CoA)
• Residual solvent and water content (Karl Fischer titration where applicable)

For bulk quantities, custom synthesis inquiries, or regulatory documentation (e.g., REACH, RoHS compliance), contact Aladdin Scientific's technical sales team. Volume pricing and availability can be confirmed through the product page or customer service.

Review flag: Exact purity specification (e.g., ≥97%, ≥98%) and available pack sizes were not stated in the source material and should be confirmed from the current product listing.