2-Butyl-4-Chloroquinoline: Handling & Application Protocol

2-Butyl-4-chloroquinoline is a halogenated quinoline intermediate widely used in medicinal chemistry and heterocyclic synthesis, requiring careful solvent selection and safety precautions during laboratory handling.

CAS Number

Not confirmed in source — see review flag

Molecular Formula

C13H14ClN

Molecular Weight

219.71 g/mol (calculated; needs verification)

Appearance

Solid (exact form not confirmed in source — see review flag)

Recommended Storage

Cool, dry place away from light and moisture (general quinoline derivative guidance)

Primary Application

Pharmaceutical intermediate and building block in heterocyclic synthesis

Materials and Safety Precautions

Before working with 2-Butyl-4-chloroquinoline (Aladdin SKU: B691120), ensure all appropriate personal protective equipment (PPE) is in place. This includes chemical-resistant gloves, a laboratory coat, and eye protection such as safety goggles. Work should be conducted in a well-ventilated fume hood due to the potential for generation of irritating vapors.

Consult the Safety Data Sheet (SDS) for B691120 prior to use for specific hazard classifications, GHS pictograms, and first-aid measures. Quinoline-based compounds may exhibit irritant properties toward skin, eyes, and respiratory mucosa. Avoid inhalation of dust or vapors.

Materials required: 2-Butyl-4-chloroquinoline (B691120), appropriate organic solvent (see Dissolution section), analytical balance, volumetric flask or vial, amber glass storage containers, molecular sieves (optional, for moisture-sensitive applications).

Stock Solution Preparation and Dissolution

2-Butyl-4-chloroquinoline is generally soluble in common organic solvents including dimethyl sulfoxide (DMSO), ethanol, dichloromethane (DCM), and tetrahydrofuran (THF). Aqueous solubility is expected to be low due to the lipophilic butyl chain and hydrophobic quinoline ring system; verify solubility for your specific application.

Preparation of a 10 mM stock solution in DMSO:

1. Tare a clean, dry microcentrifuge tube or glass vial on an analytical balance.
2. Weigh out the required mass of 2-Butyl-4-chloroquinoline (B691120). For example, to prepare 1 mL of a 10 mM solution, weigh approximately 2.20 mg (based on MW ~219.71 g/mol; verify against Certificate of Analysis).
3. Add anhydrous DMSO to the compound and vortex or sonicate gently until completely dissolved.
4. Inspect visually for complete dissolution before use. If precipitate remains, warm gently at 37 °C and re-vortex.
5. Aliquot into single-use portions to minimize freeze-thaw cycles and store at −20 °C in sealed amber vials under inert atmosphere if long-term storage is required.

Note: Confirm exact molecular weight from the Certificate of Analysis (CoA) supplied with lot B691120 before preparing solutions.

Synthetic Applications and Reaction Protocol

2-Butyl-4-chloroquinoline serves as a versatile electrophilic building block in nucleophilic aromatic substitution (SNAr) reactions, palladium-catalyzed cross-coupling reactions (e.g., Suzuki, Buchwald-Hartwig amination), and direct functionalization at the C-4 chloro position. It is relevant as an intermediate in the synthesis of biologically active quinoline scaffolds found in antimalarial, antiviral, and kinase-inhibitor research programs.

General SNAr procedure (illustrative):

1. Charge a round-bottom flask with 2-Butyl-4-chloroquinoline (1.0 equiv), the desired nucleophile (1.1–1.5 equiv), and an appropriate base (e.g., K2CO3 or Cs2CO3, 2.0 equiv) in a polar aprotic solvent (DMF or NMP) under nitrogen.
2. Heat the reaction mixture to 80–120 °C and monitor by TLC or LC-MS until starting material is consumed.
3. Cool to room temperature, dilute with ethyl acetate, wash with water and brine, dry over Na2SO4, and concentrate under reduced pressure.
4. Purify the crude product by column chromatography (silica gel, appropriate eluent system).

Important: Reaction conditions (temperature, solvent, base, equivalents) must be optimized for each specific nucleophile and target product. The above conditions are illustrative only and are not guaranteed to apply without modification.

Storage, Stability, and Disposal

Storage: Store 2-Butyl-4-chloroquinoline (B691120) in a tightly sealed container in a cool, dry location away from direct light, heat, and moisture. Recommended storage temperature and confirmed shelf-life data should be taken from the product label and CoA provided by Aladdin Scientific. General guidance for halogenated quinoline derivatives suggests storage at room temperature to 4 °C under dry conditions.

Stability: Halogenated quinoline compounds are generally stable under recommended storage conditions. However, prolonged exposure to moisture, strong acids, or strong bases may promote hydrolysis or decomposition. Retest purity (e.g., by HPLC or NMR) if the material has been stored for an extended period or if physical changes (color change, clumping) are observed.

Disposal: Dispose of 2-Butyl-4-chloroquinoline and all contaminated materials in accordance with local, national, and institutional regulations governing hazardous chemical waste. Do not dispose of via drain or general waste. Consult the SDS for B691120 and your institution's environmental health and safety (EHS) office for specific disposal guidance.

Frequently asked questions

What solvents are suitable for dissolving 2-Butyl-4-chloroquinoline?

2-Butyl-4-chloroquinoline is expected to dissolve readily in polar organic solvents such as DMSO, ethanol, DCM, and THF. Aqueous solubility is predicted to be low due to its lipophilic character. Always verify solubility empirically for your specific experimental conditions.

What reactions can 2-Butyl-4-chloroquinoline participate in as a building block?

The C-4 chloro substituent makes this compound a reactive partner in nucleophilic aromatic substitution (SNAr), palladium-catalyzed Suzuki and Buchwald-Hartwig cross-coupling reactions, and related transition-metal-mediated functionalizations. It is commonly used as a pharmaceutical intermediate for synthesizing biologically active quinoline derivatives.

How should 2-Butyl-4-chloroquinoline be stored to maintain stability?

Store the compound in a tightly sealed container in a cool, dry place, away from light, moisture, and sources of heat. Refer to the Certificate of Analysis and SDS supplied with lot B691120 for the exact recommended storage temperature and expiry information. Avoid repeated opening of the container to minimize moisture ingress.

Is 2-Butyl-4-chloroquinoline hazardous, and what PPE is required?

As a halogenated quinoline derivative, this compound should be treated as a potential irritant to skin, eyes, and the respiratory system. Standard PPE including chemical-resistant gloves, safety goggles, and a laboratory coat is required. All handling should take place in a fume hood. Consult the SDS for B691120 for full hazard classification details.

References

1. Aladdin Scientific Product Page: 2-Butyl-4-chloroquinoline, SKU B691120. Aladdin Scientific.
2. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. (General reference for SNAr and cross-coupling reactions of halogenated heterocycles.)
3. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry. Oxford University Press. (General reference for heterocyclic chemistry and nucleophilic aromatic substitution.)

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