Cyclopentanone
[CAS# 120-92-3]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty ketone (including enol)
• Name: Cyclopentanone
• Synonyms: Adipic ketone; Ketocyclopentane; Ketopentamethylene
• Molecular Formula: C₅H₈O
• Molecular Weight: 84.12
• CAS Registry Number: 120-92-3
• EC Number: 204-435-9
• SMILES: C1CCC(=O)C1

Properties

• Density: 0.951
• Melting point: -51 °C
• Boiling point: 130-131 °C
• Refractive index: 1.436-1.438
• Flash point: 31 °C
• Water solubility: PRACTICALLY INSOLUBLE

Safety Data

• Hazard Symbols: GHS02;GHS07 Warning
• Risk Statements: H226-H315-H319-H332
• Safety Statements: P210-P233-P240-P241-P242-P243-P261-P264-P264+P265-P271-P280-P302+P352-P303+P361+P353-P304+P340-P305+P351+P338-P317-P321-P332+P317-P337+P317-P362+P364-P370+P378-P403+P235-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2A	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335

• Transport Information: UN 2245

Discovery and Applications

Cyclopentanone is a cyclic ketone with the molecular formula C5H8O, characterized by a five-membered ring structure containing a carbonyl group (C=O). This compound is colorless and has a distinctive odor, reminiscent of peppermint or camphor. The discovery of cyclopentanone dates back to the early 20th century, when chemists were exploring various methods for synthesizing cyclic compounds and studying their properties.

The synthesis of cyclopentanone can be achieved through several methods, with one notable approach being the oxidation of cyclopentanol. Other synthetic routes include the cyclization of suitable precursors, such as pentanoyl chloride. The compound’s structure and properties have made it a subject of interest in organic chemistry, leading to its study in various applications.

Cyclopentanone is widely used as an intermediate in organic synthesis and serves as a precursor for the production of other chemical compounds. Its versatility allows it to participate in a variety of reactions, such as aldol condensations, Michael additions, and nucleophilic substitutions. This property makes cyclopentanone an important building block in the synthesis of pharmaceuticals, agrochemicals, and fragrances.

In the pharmaceutical industry, cyclopentanone derivatives are utilized in the synthesis of biologically active compounds. For instance, cyclopentanone has been involved in the development of certain analgesics and anti-inflammatory agents. Its ability to undergo ring-opening reactions also enables the formation of larger, more complex molecules, further enhancing its utility in drug design.

Moreover, cyclopentanone finds applications in the field of materials science, particularly in the synthesis of polymers and resins. Its reactivity allows for the incorporation of cyclopentanone into various polymeric materials, improving properties such as flexibility and thermal stability. Additionally, the compound is used in the manufacture of certain surfactants and plasticizers, contributing to the development of high-performance materials.

Research into cyclopentanone continues to evolve, with ongoing studies focused on its reactivity and potential applications in novel chemical processes. Its role as a versatile intermediate underscores its importance in both industrial and academic research, highlighting the significance of cyclopentanone in advancing organic chemistry and materials science.

References

2008. The conjugate addition-Peterson olefination reaction for the preparation of cross-conjugated cyclopentenone, PPAR-gamma ligands. Organic & Biomolecular Chemistry.
DOI: 10.1039/b814619e

2012. Microwave-Assisted Synthesis of Cyclopentanones Using the Relevant Phosphorus Ylides. Combinatorial Chemistry & High Throughput Screening.
DOI: 10.2174/138620712799361889

2024. Cyclopentyl Methyl Ether (CPME). Biorenewable Solvents for Organic Synthesis.
DOI: 10.1007/978-3-031-74346-7_3