4,7-Dichloroquinoline: Properties, Uses & FAQs

4,7-Dichloroquinoline is a halogenated quinoline heterocycle widely used as a key synthetic intermediate in the preparation of antimalarial drugs and other biologically active quinoline-based compounds.

CAS Number

86-98-6

Molecular Formula

C₉H₅Cl₂N

Molecular Weight

198.05 g/mol

Appearance

White to off-white crystalline solid

Primary Application

Synthetic intermediate for antimalarial agents (e.g., chloroquine analogues)

Storage Condition

Cool, dry, well-ventilated area; away from light and moisture

What Is 4,7-Dichloroquinoline?

4,7-Dichloroquinoline (CAS 86-98-6) is a bicyclic aromatic heterocycle consisting of a benzene ring fused to a pyridine ring, with chlorine substituents at the 4- and 7-positions. The compound has the molecular formula C₉H₅Cl₂N and a molecular weight of approximately 198.05 g/mol. It appears as a white to off-white crystalline solid at room temperature.

The two chlorine atoms dramatically influence the electronic character of the quinoline ring: the 4-position chlorine is highly activated toward nucleophilic aromatic substitution (SNAr) due to the electron-withdrawing ring nitrogen, while the 7-position chlorine is somewhat less reactive. This differential reactivity makes 4,7-dichloroquinoline a versatile building block for medicinal chemistry.

Key Research and Synthetic Applications

4,7-Dichloroquinoline is best known as the central precursor in the synthesis of 4-aminoquinoline antimalarial drugs, most notably chloroquine and its structural analogues. In these syntheses, a diamine or amino alcohol undergoes selective SNAr displacement of the 4-position chlorine, leaving the 7-chloro substituent intact as part of the pharmacophore.

Beyond antimalarials, researchers employ 4,7-dichloroquinoline as a scaffold for:

• Antiprotozoal and antileishmanial compound libraries
• Fluorescent probe development via palladium-catalyzed cross-coupling (Suzuki, Sonogashira) at the 4- or 7-position
• Coordination chemistry, as quinoline-based ligands for transition-metal complexes
• Structure–activity relationship (SAR) studies exploring halogen effects on biological potency

Its dual electrophilic sites allow sequential functionalization, making it particularly attractive for combinatorial chemistry workflows.

Handling, Safety and Storage Guidelines

4,7-Dichloroquinoline should be handled in accordance with standard laboratory safety practices for halogenated aromatic compounds. Key precautions include:

• Personal protective equipment: Wear chemical-resistant gloves, safety goggles, and a lab coat. Work in a fume hood to avoid inhalation of dust or vapors.
• Storage: Store in a tightly sealed container in a cool (below 25 °C), dry, well-ventilated location, away from light, moisture, and incompatible oxidizing agents.
• Stability: The compound is stable under recommended storage conditions; prolonged exposure to moisture or light may cause discoloration without necessarily compromising purity, but verification by analytical methods (HPLC, melting point) is advised before use in sensitive assays.
• Disposal: Dispose of waste in accordance with local regulations for halogenated organics.

Always consult the product-specific Safety Data Sheet (SDS) before use.

Purity Grades and Quality Considerations

For research applications, 4,7-dichloroquinoline is typically available in grades ranging from 97% to ≥98% purity as determined by GC or HPLC analysis. Selecting the appropriate purity grade depends on the intended use:

• Synthetic chemistry: Technical or 97% grade is generally sufficient for large-scale reactions where downstream purification steps are planned.
• Medicinal chemistry / SAR studies: ≥98% HPLC-grade material is recommended to minimize interference from structurally similar impurities that could skew biological assay results.
• Reference standard use: Certified reference materials with documented analytical certificates of analysis (CoA) are required.

Key quality parameters to review on the CoA include: purity by GC or HPLC, melting point (literature value should be confirmed at time of purchase), water content (Karl Fischer), and appearance. Contact Aladdin Scientific technical support if custom purity specifications are required.

Ordering and Product Information at Aladdin Scientific

Aladdin Scientific supplies 4,7-Dichloroquinoline under SKU D155356. When placing an order, consider the following:

• Pack sizes: Multiple pack sizes are typically available to suit both exploratory (small-scale) and preparative (bulk) needs. Check the product page for current availability.
• Lead time: In-stock items generally ship within 1–3 business days. Out-of-stock or custom quantities may require additional lead time; contact customer service for estimated delivery windows.
• Documentation: A Certificate of Analysis (CoA) and Safety Data Sheet (SDS) are available for download on the product page or upon request.
• Regulatory compliance: Export control and import regulations may apply to halogenated heterocyclic compounds depending on destination country. Buyers are advised to verify local requirements before ordering.

For bulk pricing, custom packaging, or technical inquiries, contact Aladdin Scientific's sales and technical support teams directly through the website.

Frequently asked questions

What is 4,7-Dichloroquinoline primarily used for in research?

4,7-Dichloroquinoline is primarily used as a key synthetic intermediate for the preparation of 4-aminoquinoline antimalarial compounds, including chloroquine analogues. It is also used as a scaffold in antiprotozoal research, cross-coupling chemistry, and coordination chemistry involving quinoline-based metal ligands.

Which chlorine position in 4,7-Dichloroquinoline is more reactive toward nucleophilic substitution?

The 4-position chlorine is significantly more reactive toward nucleophilic aromatic substitution (SNAr) than the 7-position chlorine. This is because the adjacent ring nitrogen strongly activates the 4-position toward nucleophilic attack, enabling selective mono-functionalization under mild conditions. This selectivity is exploited in the synthesis of chloroquine analogues where amines selectively displace the 4-chloro group.

How should 4,7-Dichloroquinoline be stored to maintain its purity?

4,7-Dichloroquinoline should be stored in a tightly sealed container in a cool (below 25 °C), dry, and well-ventilated area, protected from light and moisture. Under these conditions the compound is stable for extended periods. It is recommended to verify purity by HPLC or melting point determination if the material has been stored for a long time before use in critical experiments.

What purity grade of 4,7-Dichloroquinoline should I order for biological assays?

For biological assays and medicinal chemistry SAR studies, ≥98% purity (HPLC-grade) is recommended to minimize the risk of structurally related impurities interfering with assay results. Always request a Certificate of Analysis (CoA) to confirm the purity and key physicochemical parameters of the specific lot you receive.

Is 4,7-Dichloroquinoline available in bulk quantities from Aladdin Scientific?

Yes, Aladdin Scientific offers 4,7-Dichloroquinoline (SKU: D155356) in multiple pack sizes. For bulk quantities, custom packaging, or special pricing, it is recommended to contact Aladdin Scientific's sales team directly through the website for a tailored quotation and estimated lead time.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. General reference for nucleophilic aromatic substitution on halogenated heterocycles.
2. Dua, R. et al. Pharmacological significance of synthetic quinolines and their derivatives. Mini-Reviews in Medicinal Chemistry. General reference for quinoline antimalarial applications.
3. Aladdin Scientific product page for 4,7-Dichloroquinoline, SKU D155356. Certificate of Analysis and Safety Data Sheet available on request.

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