4-Chlorobutanal: Properties, Handling & Lab Use Guide

4-Chlorobutanal is a bifunctional halogenated aldehyde widely used as a reactive intermediate in organic synthesis, offering both an electrophilic aldehyde carbonyl and a terminal alkyl chloride for versatile chemical transformations.

Chemical Name

4-Chlorobutanal

Molecular Formula

C₄H₇ClO

Molecular Weight

106.55 g/mol

CAS Number

6139-84-0

Functional Groups

Aldehyde (–CHO) and alkyl chloride (–CH₂Cl)

Primary Application

Organic synthesis intermediate; building block for heterocycles and complex molecules

Storage Condition

Store in a cool, dry, well-ventilated area, away from oxidizers and ignition sources

SKU

C691521

Chemical Properties and Structure

4-Chlorobutanal (CAS 6139-84-0) is a short-chain, bifunctional organic compound with the molecular formula C₄H₇ClO and a molecular weight of approximately 106.55 g/mol. Its structure features a four-carbon chain bearing an aldehyde group at the C-1 position and a chlorine substituent at the C-4 (terminal) position.

The aldehyde carbonyl is highly electrophilic and readily participates in nucleophilic addition reactions, while the primary alkyl chloride at the distal end serves as a leaving group in substitution and cyclization reactions. This dual reactivity makes 4-Chlorobutanal a particularly versatile building block in synthetic chemistry.

The compound is expected to be a colorless to light yellow liquid under standard conditions. It is reactive and may undergo self-condensation (aldol-type reactions) over time, particularly under basic conditions or elevated temperatures. Researchers should verify physical constants (boiling point, density, refractive index) against the Certificate of Analysis supplied with each batch.

Synthetic Applications and Research Uses

4-Chlorobutanal serves as a valuable two-point electrophile in organic synthesis. The simultaneous presence of a reactive aldehyde and a primary alkyl chloride allows chemists to exploit either or both functional groups sequentially or in tandem reactions.

Cyclization reactions: The 1,4-bifunctional arrangement is ideally suited for the synthesis of five-membered ring heterocycles. For example, reaction with bifunctional nucleophiles such as diamines or amino alcohols can give pyrrolidine, tetrahydrofuran, or related scaffolds, depending on reaction conditions and nucleophile selection.

Nucleophilic addition to the aldehyde: Grignard reagents, organolithium compounds, hydride reducing agents, and Wittig ylides can react selectively at the aldehyde carbonyl to elaborate the carbon framework while preserving the C–Cl bond for subsequent displacement.

Substitution at the alkyl chloride: The terminal chloride undergoes nucleophilic substitution (S_N2) with a variety of nucleophiles including amines, thiols, cyanide, and azide, enabling introduction of diverse heteroatom functionalities.

Pharmaceutical and agrochemical intermediates: Halogenated aldehydes of this type are commonly employed in the preparation of biologically active compounds and natural product analogues. Specific literature targets should be identified in primary publications prior to use.

Safe Handling, Storage and Disposal

Personal Protective Equipment (PPE): Always wear appropriate PPE when handling 4-Chlorobutanal, including chemical-resistant gloves (e.g., nitrile or neoprene), safety goggles or a face shield, and a laboratory coat. Work in a certified fume hood at all times to avoid inhalation of vapors.

Hazard awareness: As a halogenated aldehyde, 4-Chlorobutanal is expected to be an irritant to the skin, eyes, and respiratory tract. The compound may also be a lachrymatory agent owing to the aldehyde functionality. Consult the Safety Data Sheet (SDS) provided by Aladdin Scientific for the full hazard classification and first-aid measures before use. Specific GHS hazard codes and pictograms should be confirmed from the current SDS.

Storage: Store in a tightly sealed container in a cool (recommended ≤ 4 °C for long-term stability), dry, well-ventilated location. Keep away from oxidizing agents, strong bases, and sources of ignition. Protect from light to minimize aldehyde oxidation and polymerization side reactions.

Disposal: Dispose of waste material and contaminated items in accordance with local, regional, and national regulations governing halogenated organic waste. Do not pour down the drain. Segregate from non-halogenated waste streams as required by your institution.

Quality, Purity and Regulatory Considerations

Purity and specification: Aladdin Scientific supplies 4-Chlorobutanal (SKU: C691521) as a research-grade reagent. The purity specification and analytical data (e.g., GC purity, NMR) are detailed on the product's Certificate of Analysis (CoA), which is available on request or via the Aladdin website. Researchers should always verify the CoA before commencing sensitive synthetic work.

Stability considerations: Aldehydes are susceptible to aerial oxidation to the corresponding carboxylic acid and can undergo oligomerization. Upon receipt, inspect the reagent and note the lot number. For long-term projects, smaller quantity purchases may be preferable to minimize repeated freeze-thaw cycles or prolonged open-vessel exposure.

Regulatory status: End-users are responsible for ensuring that the purchase and use of 4-Chlorobutanal comply with all applicable local and national regulations. Certain halogenated building blocks may be subject to controlled substance or export-control regulations depending on jurisdiction; consult your institution's compliance office if in doubt.

Documentation: Retain the SDS, CoA, and purchase records as part of your laboratory's chemical inventory management system. These documents support safety audits, insurance requirements, and good laboratory practice (GLP) compliance.

Frequently asked questions

What is 4-Chlorobutanal used for in organic synthesis?

4-Chlorobutanal is used as a bifunctional synthetic building block. Its aldehyde group participates in nucleophilic additions, condensations, and reductive aminations, while the terminal alkyl chloride undergoes nucleophilic substitution or intramolecular cyclization. This makes it particularly useful for constructing five-membered heterocyclic rings and elaborating complex molecular scaffolds.

How should 4-Chlorobutanal be stored to maintain stability?

4-Chlorobutanal should be stored in a tightly sealed container at low temperature (≤ 4 °C is recommended for long-term storage), in a dry, dark, and well-ventilated area away from oxidizers, strong bases, and ignition sources. These precautions minimize aerial oxidation of the aldehyde and prevent oligomerization or side reactions over time.

What personal protective equipment is required when handling 4-Chlorobutanal?

Researchers should wear chemical-resistant gloves (nitrile or neoprene), safety goggles or a face shield, and a laboratory coat whenever handling 4-Chlorobutanal. All operations should be conducted inside a certified fume hood to prevent inhalation of vapors. The full hazard profile and first-aid procedures are described in the product Safety Data Sheet, which should be reviewed before first use.

How do I confirm the purity of the 4-Chlorobutanal I receive?

Each batch of Aladdin Scientific's 4-Chlorobutanal (SKU: C691521) is accompanied by a Certificate of Analysis (CoA) that details the lot-specific purity data, typically determined by gas chromatography (GC) and/or NMR spectroscopy. Customers can request the CoA through the Aladdin Scientific website or customer service team. Always match the lot number on the bottle to the CoA before use.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley: New York, 1992. (General reference for aldehyde and alkyl halide reactivity.)
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (Reference for nucleophilic addition to aldehydes and SN2 reactions of alkyl chlorides.)
3. Aladdin Scientific. Safety Data Sheet: 4-Chlorobutanal (C691521). Shanghai, China. (Consult current version for GHS hazard classification, PPE requirements, and disposal guidance.)

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