2,4-Pentanedione
[CAS# 123-54-6]

Identification

• Classification: Organic raw materials >> Ketone compound
• Name: 2,4-Pentanedione
• Synonyms: Acetylacetone
• Molecular Formula: C₅H₈O₂
• Molecular Weight: 100.12
• CAS Registry Number: 123-54-6
• EC Number: 204-634-0
• SMILES: CC(=O)CC(=O)C

Properties

• Density: 0.975
• Melting point: -23 °C
• Boiling point: 133-140 °C
• Refractive index: 1.451-1.453
• Flash point: 35.5 °C
• Water solubility: 16 g/100 mL (20 °C)

Safety Data

• Hazard Symbols: GHS02;GHS06;GHS07 Danger
• Risk Statements: H226-H302-H311-H331
• Safety Statements: P210-P233-P240-P241-P242-P243-P261-P262-P264-P270-P271-P280-P301+P317-P302+P352-P303+P361+P353-P304+P340-P316-P321-P330-P361+P364-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	3	H331
Skin sensitization	Skin Sens.	1	H317
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Acute toxicity	Acute Tox.	3	H301
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315

• Transport Information: UN 2310

Discovery and Applications

2,4-Pentanedione, also known as acetylacetone, is an organic compound with the molecular formula C5H8O2. This diketone has gained attention since its discovery in the early 20th century due to its unique chemical properties and versatile applications in various fields. The compound is a colorless to pale yellow liquid that is soluble in water, alcohol, and other organic solvents, making it a valuable reagent in synthetic chemistry.

The synthesis of 2,4-pentanedione can be achieved through several methods, including the condensation of two molecules of acetylacetone or via the cyclization of 3-oxobutanoic acid. One of the most common methods involves the reaction of acetic anhydride with sodium acetate, leading to the formation of the diketone. This process was developed to streamline the production of 2,4-pentanedione for use in different applications.

2,4-Pentanedione serves as an important building block in organic synthesis, particularly in the preparation of metal chelates. The compound readily forms stable complexes with various metal ions, including copper, nickel, and iron. These chelates are utilized in numerous applications, such as catalysis, pigment production, and as precursors in the synthesis of pharmaceuticals and agrochemicals. The ability of 2,4-pentanedione to stabilize metal ions is particularly valuable in the production of high-performance catalysts used in organic reactions.

In the field of materials science, 2,4-pentanedione is employed in the synthesis of polymers and coatings. It acts as a crosslinking agent, enhancing the mechanical properties and thermal stability of polymeric materials. The incorporation of 2,4-pentanedione into polymer formulations can improve the durability and longevity of coatings, making it an essential component in industrial applications.

Another significant application of 2,4-pentanedione is in the pharmaceutical industry, where it is used as an intermediate in the synthesis of various biologically active compounds. The diketone's ability to undergo diverse chemical transformations allows for the creation of a wide range of pharmaceutical agents, including anti-inflammatory drugs and antibiotics. Additionally, 2,4-pentanedione serves as a solvent for numerous organic reactions, providing a medium in which chemical processes can occur efficiently.

Moreover, 2,4-pentanedione is commonly utilized as a flavoring agent in the food industry due to its pleasant, buttery flavor profile. It is often found in baked goods, dairy products, and confectioneries, enhancing the sensory experience of food products. Its use in food applications is regulated to ensure safety and compliance with health standards.

Despite its versatility, safety considerations must be observed when handling 2,4-pentanedione. The compound can cause irritation to the skin, eyes, and respiratory tract upon exposure. Therefore, proper safety precautions, including the use of personal protective equipment and adequate ventilation, are essential when working with this substance in laboratories and industrial settings.

In summary, 2,4-pentanedione is a valuable compound with a wide range of applications in organic synthesis, materials science, pharmaceuticals, and food flavoring. Its discovery and continued utilization highlight the significance of diketones in chemical research and industry. As new applications are explored, 2,4-pentanedione is likely to remain an important reagent in various fields of science and technology.

References

2005. Pharmacodynamics and pharmacokinetics of the insulin-mimetic agent vanadyl acetylacetonate in non-diabetic and diabetic rats. Journal of Inorganic Biochemistry.
DOI: 10.1016/j.jinorgbio.2005.01.015

2008. Atmospheric Chemistry of Acetylacetone. Environmental Science & Technology.
DOI: 10.1021/es8010282

2012. A Facile Synthesis of MPd (M = Co, Cu) Nanoparticles and Their Catalysis for Formic Acid Oxidation. Nano Letters.
DOI: 10.1021/nl2045588