5-Chloro-2-ethylpyridine: Properties, Uses & Lab Guide

5-Chloro-2-ethylpyridine is a halogenated alkylpyridine building block widely employed in pharmaceutical and agrochemical synthesis as a versatile intermediate for C–N, C–C, and nucleophilic aromatic substitution reactions.

IUPAC Name

5-Chloro-2-ethylpyridine

Molecular Formula

C7H8ClN

Molecular Weight

141.60 g/mol

CAS Number

To be confirmed — see review flag

SKU

C729561

Functional Groups

Pyridine ring, C-5 chloro substituent, C-2 ethyl substituent

Key Reactivity

Nucleophilic aromatic substitution (SNAr) at C-5; cross-coupling at C-5; directed metalation at C-3

Chemical Identity and Structure

5-Chloro-2-ethylpyridine (SKU C729561) is a six-membered nitrogen-containing heterocycle bearing a chlorine atom at the 5-position and an ethyl group at the 2-position of the pyridine ring. Its molecular formula is C₇H₈ClN with a molecular weight of approximately 141.60 g/mol.

The electron-withdrawing nature of the ring nitrogen and the chloro substituent together activate the C-5 carbon toward nucleophilic aromatic substitution (SNAr), while the ethyl group at C-2 confers a degree of steric and electronic bias useful for directing subsequent functionalization. The compound is typically encountered as a colorless to pale-yellow liquid or low-melting solid; specific physical constants (melting point, boiling point, density, refractive index) should be verified from the certificate of analysis supplied with each lot.

Synthesis Relevance and Reaction Chemistry

As a bifunctional pyridine building block, 5-Chloro-2-ethylpyridine participates in several strategically important transformations:

• Nucleophilic Aromatic Substitution (SNAr): The C-5 chlorine is susceptible to displacement by amines, alkoxides, and thiolates under mild to moderate conditions, providing rapid access to 5-amino-, 5-alkoxy-, and 5-thioetherpyridine analogues.
• Transition-Metal-Catalyzed Cross-Coupling: The aryl C–Cl bond can participate in Suzuki–Miyaura, Negishi, and Buchwald–Hartwig protocols with appropriate palladium or nickel catalysts, enabling C–C and C–N bond formation.
• Directed Ortho-Metalation: The ethyl group at C-2, combined with the nitrogen directing effect, can facilitate lithiation at C-3 under cryogenic conditions, opening pathways to further substituted derivatives.
• Side-Chain Functionalization: The benzylic methylene of the ethyl group is susceptible to radical or ionic bromination, providing additional handles for further elaboration.

These attributes make 5-Chloro-2-ethylpyridine a valuable intermediate in multi-step synthesis campaigns targeting pharmaceuticals, crop-protection agents, and specialty materials.

Laboratory Handling, Storage and Safety

Although a full safety assessment must be based on the supplier's Safety Data Sheet (SDS) for lot C729561, general precautions applicable to halogenated pyridines include:

• Personal Protective Equipment: Wear chemical-splash goggles, nitrile gloves, and a lab coat. Work in a well-ventilated fume hood to minimize inhalation exposure to vapors.
• Storage: Store in a tightly sealed container under inert atmosphere (nitrogen or argon) at 2–8 °C or as specified on the product label. Protect from moisture, light, and strong oxidizing agents.
• Waste Disposal: Dispose of residues and contaminated materials as halogenated organic waste in accordance with local, institutional, and regulatory requirements.
• First Aid: In case of skin or eye contact, flush immediately with copious water for at least 15 minutes and seek medical attention. If inhaled, remove to fresh air.

Always consult the current SDS before use. Specific hazard classifications (GHS pictograms, H-statements, P-statements) should be verified from the documentation accompanying each shipment.

Quality, Purity and Ordering Information

Aladdin Scientific supplies 5-Chloro-2-ethylpyridine under SKU C729561. Key quality attributes to request at time of ordering include:

• Purity: Confirmed by GC or HPLC; typical research-grade material is ≥95% or ≥98%. Confirm the specification tier required for your application before purchase.
• Analytical Documentation: Certificate of Analysis (CoA) including lot-specific purity, NMR confirmation of structure, and residual solvent data where applicable.
• Pack Sizes: Available in multiple quantities to suit discovery-scale screening through gram-scale synthesis; contact Aladdin Scientific for bulk or custom requirements.
• Lead Time: Standard in-stock items typically ship within 1–3 business days; verify current stock status and lead times with the Aladdin Scientific sales team or online catalog.

For pricing, promotional offers, or reward-point redemption, please refer to the Aladdin Scientific website or contact customer service directly.

Frequently asked questions

What is the molecular formula and molecular weight of 5-Chloro-2-ethylpyridine?

5-Chloro-2-ethylpyridine has the molecular formula C7H8ClN and a molecular weight of approximately 141.60 g/mol. These values are derived from its structural composition: a pyridine ring with a chloro substituent at C-5 and an ethyl group at C-2.

What types of chemical reactions can 5-Chloro-2-ethylpyridine participate in?

The compound is versatile in synthesis: the C-5 chloro group undergoes nucleophilic aromatic substitution (SNAr) with amines, alkoxides, and thiolates, and participates in palladium- or nickel-catalyzed cross-coupling reactions (e.g., Suzuki–Miyaura, Buchwald–Hartwig). The ethyl side chain can also be functionalized via benzylic bromination.

How should 5-Chloro-2-ethylpyridine (SKU C729561) be stored?

As a general guideline for halogenated pyridine intermediates, the compound should be stored in a tightly sealed container under an inert atmosphere at 2–8 °C, protected from light, moisture, and oxidizing agents. Always refer to the product label and current SDS for lot-specific storage instructions.

Is 5-Chloro-2-ethylpyridine suitable as a pharmaceutical intermediate?

Yes, pyridine derivatives bearing halogen and alkyl substituents are frequently used as intermediates in pharmaceutical synthesis due to their ability to undergo selective functionalization. 5-Chloro-2-ethylpyridine's reactivity profile makes it a useful building block for medicinal chemistry programs, though suitability for any specific application should be verified by the researcher.

How do I obtain a Certificate of Analysis for lot C729561?

Certificates of Analysis for Aladdin Scientific products can be downloaded from the product page on the Aladdin Scientific website using the lot number, or requested directly from customer service. The CoA includes lot-specific purity data and structural confirmation.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley: New York, 1992. (General reference for SNAr and cross-coupling chemistry of aryl halides.)
2. Joule, J. A.; Mills, K. Heterocyclic Chemistry, 5th ed.; Wiley-Blackwell: Oxford, 2010. (Textbook-level reference for pyridine reactivity and functionalization strategies.)
3. Aladdin Scientific. Product Page: 5-Chloro-2-ethylpyridine, SKU C729561. Aladdin Scientific website (accessed 2024).

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