Butyraldehyde: Properties, Uses & Lab Handling Guide

Butyraldehyde is a short-chain aliphatic aldehyde widely used as a reactive intermediate in organic synthesis and industrial chemical manufacturing.

IUPAC Name

Butanal

Molecular Formula

C₄H₈O

Characteristic Odor

Pungent, sharp aldehyde odor

Flammability

Flammable liquid

Miscibility

Miscible with ethanol, diethyl ether, ethyl acetate, acetone, toluene, and oils

SKU

B100302B

Chemical Identity and Physical Properties

Butyraldehyde (IUPAC name: butanal) is a four-carbon aliphatic aldehyde with the molecular formula C₄H₈O. It is a colorless, mobile liquid at room temperature and is immediately recognizable by its pungent, sharp aldehyde odor. The compound belongs to the homologous series of saturated aliphatic aldehydes and carries a reactive carbonyl (C=O) functional group that governs much of its chemistry.

Butyraldehyde is fully miscible with common organic solvents including ethanol, diethyl ether, ethyl acetate, acetone, and toluene, as well as with oils, making it convenient to incorporate into a broad range of reaction media and formulations. Its relatively low molecular weight and high reactivity make it a versatile building block in synthetic chemistry.

Key Applications and Industrial Uses

Butyraldehyde serves as an important industrial and laboratory chemical intermediate. In industry, it is a principal precursor in the synthesis of 2-ethylhexanol, n-butanol, and butyric acid, which are themselves feedstocks for plasticizers, solvents, and flavoring agents. The aldehyde group readily undergoes aldol condensation, oxidation, reduction, and nucleophilic addition reactions, enabling access to a diverse array of downstream products.

In laboratory research, butyraldehyde is employed in organic synthesis as a C4 aldehyde building block for the preparation of heterocycles, fine chemicals, and pharmaceutical intermediates. Its reactivity with amines (forming imines), with active methylene compounds (via Knoevenagel condensation), and with reducing agents (to give n-butanol) exemplifies the range of transformations available to synthetic chemists.

Safety, Storage, and Handling

Butyraldehyde is classified as a flammable liquid and must be handled with appropriate precautions. Work should be conducted in a well-ventilated fume hood away from open flames, sparks, and other ignition sources. Personnel should wear appropriate personal protective equipment (PPE) including chemical-resistant gloves, safety goggles, and a lab coat. The sharp, irritating aldehyde vapor can cause irritation to the eyes, skin, and respiratory tract upon exposure.

The compound should be stored in tightly sealed containers in a cool, dry, well-ventilated area, segregated from oxidizing agents and strong acids. Ground and bond containers when transferring to prevent electrostatic discharge. Spills should be contained immediately using inert absorbent material and disposed of in accordance with local regulations. Consult the Safety Data Sheet (SDS) for complete hazard information before use.

Reactivity and Compatibility

As an aliphatic aldehyde, butyraldehyde exhibits high chemical reactivity owing to the electrophilic carbonyl carbon. It is susceptible to auto-oxidation in air, potentially forming peroxides or butyric acid over time; therefore, containers should be kept tightly closed and the reagent used within a reasonable period after opening. Butyraldehyde can polymerize under acidic or basic conditions and may react vigorously with strong oxidizers, strong bases, and reducing agents.

Its broad miscibility with organic solvents (ethanol, diethyl ether, ethyl acetate, acetone, toluene) and oils facilitates homogeneous reaction conditions. However, incompatibility with water (limited miscibility at higher concentrations), concentrated mineral acids, and strong oxidizing agents should be noted when designing reaction protocols or selecting storage conditions.

Frequently asked questions

What solvents is butyraldehyde miscible with?

Butyraldehyde is miscible with ethanol, diethyl ether, ethyl acetate, acetone, toluene, and oils. This broad solubility profile makes it compatible with a wide range of organic reaction media.

Is butyraldehyde flammable, and what precautions should I take?

Yes, butyraldehyde is a flammable liquid. It should be used in a well-ventilated fume hood, kept away from all ignition sources, and stored in tightly sealed containers in a cool, dry location. Appropriate PPE including gloves, goggles, and a lab coat must be worn at all times.

What are the main laboratory uses of butyraldehyde?

In the laboratory, butyraldehyde is primarily used as a C4 aldehyde building block in organic synthesis. Common applications include aldol condensations, imine formation with amines, Knoevenagel condensations, and reductions to n-butanol. It also serves as an intermediate for pharmaceutical and fine chemical synthesis.

How should butyraldehyde be stored to maintain reagent integrity?

Butyraldehyde should be stored in tightly closed containers under cool, dry, and well-ventilated conditions, away from oxidizing agents and strong acids. Because it is prone to auto-oxidation and potential peroxide formation on prolonged exposure to air, containers should be resealed promptly after use and the reagent should be checked for quality before use in sensitive reactions.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. (General reference for aldehyde reactivity and synthesis.)
2. Aladdin Scientific Product Page: Butyraldehyde, SKU B100302B.
3. National Institute for Occupational Safety and Health (NIOSH). Chemical Hazards — Butyraldehyde. (General safety reference.)

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