Cyclopentanone Oxime: Properties, Handling & Lab Guidelines

Cyclopentanone Oxime is a crystalline oxime compound derived from cyclopentanone and hydroxylamine, widely used as a synthetic intermediate in organic chemistry, particularly as a precursor in Beckmann rearrangement reactions leading to lactam formation.

Chemical Name

Cyclopentanone Oxime

Molecular Formula

C₅H₉NO

Molecular Weight

99.13 g/mol

Physical Form

White to off-white crystalline solid

Key Reaction

Beckmann rearrangement to ε-caprolactam analogue (2-azacyclohexanone)

SKU

C138083

Chemical Properties and Identity

Cyclopentanone Oxime (CAS number requires verification) is the condensation product of cyclopentanone and hydroxylamine. Its molecular formula is C₅H₉NO with a molecular weight of approximately 99.13 g/mol. The compound exists as a stable crystalline solid at room temperature, typically presenting as white or off-white crystals.

Oximes of this class are characterized by a carbon–nitrogen double bond (C=N) bearing a hydroxyl group (–OH) on the nitrogen atom. This functional group arrangement confers moderate polarity and the ability to participate in hydrogen bonding, influencing solubility in polar solvents such as ethanol, methanol, and ethyl acetate. Solubility in water is limited compared to aliphatic counterparts due to the cyclopentyl ring.

The E/Z (syn/anti) isomerism arising from restricted rotation about the C=N bond is a well-known feature of cyclic ketone oximes. Researchers should confirm the predominant isomeric form in the batch certificate of analysis, as isomeric ratio can influence reactivity in downstream transformations.

Synthesis and Primary Research Applications

Preparation: Cyclopentanone Oxime is conventionally synthesized by reacting cyclopentanone with hydroxylamine hydrochloride in the presence of a base (e.g., sodium acetate or pyridine) in aqueous or mixed-solvent systems. The reaction proceeds via nucleophilic addition of hydroxylamine to the ketone carbonyl, followed by dehydration to form the oxime. Yield and purity are typically high under mild conditions.

Beckmann Rearrangement: The most significant application of Cyclopentanone Oxime in synthetic chemistry is as a substrate for the Beckmann rearrangement. Under acidic conditions (e.g., sulfuric acid, polyphosphoric acid, or Lewis acid catalysts) or photochemical conditions, the oxime undergoes rearrangement to yield a lactam — specifically 2-azacyclohexanone (δ-valerolactam). This transformation is of fundamental importance in the industrial synthesis of lactam monomers and in academic mechanistic studies of rearrangement reactions.

Coordination Chemistry: Oximes serve as versatile ligands in coordination chemistry, and Cyclopentanone Oxime may be employed in the preparation of metal complexes for catalytic or materials applications. Researchers working in this area should consult primary literature for specific binding constants and complex stability data.

Intermediate for Further Functionalization: The oxime nitrogen–oxygen bond can be cleaved or transformed (e.g., O-acylation, O-sulfonylation) to generate reactive intermediates such as nitrones or nitrile oxides, expanding the utility of this compound in heterocyclic synthesis and 1,3-dipolar cycloaddition chemistry.

Safe Handling, Storage and Waste Disposal

General Precautions: Although Cyclopentanone Oxime is considered to be of moderate hazard compared to many reactive intermediates, standard laboratory chemical hygiene practices must be followed at all times. Avoid inhalation of dust or aerosols, skin contact, and eye exposure. Use in a well-ventilated fume hood.

Personal Protective Equipment (PPE): Wear appropriate chemical-resistant gloves (nitrile recommended), laboratory coat, and safety goggles or face shield when weighing or handling this compound. Wash hands thoroughly after handling.

Storage Conditions: Store in a tightly sealed container in a cool, dry, well-ventilated location away from heat sources, open flames, and incompatible materials (strong oxidizing agents, strong acids). Recommended storage temperature is typically 2–25 °C; consult the product label and Safety Data Sheet (SDS) for the precise storage specification applicable to the current lot.

Stability: The compound is expected to be stable under recommended storage conditions. Prolonged exposure to moisture, heat, or light may promote decomposition. Inspect the material visually before use; any discoloration or off-odor should be flagged and the SDS consulted.

Waste Disposal: Dispose of as chemical waste in accordance with local, regional, and national regulations. Do not pour down drains or discard with general laboratory waste. Contact your institutional environmental health and safety office for guidance on appropriate disposal pathways for nitrogen-containing organic compounds.

Purity, Quality Specifications and Procurement

Specification: Aladdin Scientific supplies Cyclopentanone Oxime (SKU: C138083) at research-reagent grade. The exact purity specification, lot-specific analytical data, and certificate of analysis (CoA) are available on the product page or upon request from customer service. Researchers requiring high-purity material for sensitive assays should verify the purity grade prior to ordering.

Analytical Methods: Purity is typically assessed by gas chromatography (GC) or high-performance liquid chromatography (HPLC). Structural confirmation may be provided by nuclear magnetic resonance (NMR) spectroscopy and/or mass spectrometry (MS). Melting point determination is a simple orthogonal check for identity and purity; literature values should be confirmed against the CoA.

Ordering: Place orders directly through the Aladdin Scientific website or via your institutional procurement system. For bulk quantities, custom packaging, or special purity requirements, contact the Aladdin Scientific sales team. Reward points, promotional pricing, and institutional account benefits may apply — log in to your account to access current offers.

Returns and Quality Issues: If the received product does not meet the stated specification, contact Aladdin Scientific customer service promptly with the lot number and CoA reference. Returns are processed in accordance with the company's returns and refund policy.

Regulatory Considerations and Documentation

Safety Data Sheet (SDS): An up-to-date SDS compliant with GHS/OSHA HazCom standards is available for Cyclopentanone Oxime through the Aladdin Scientific product page. All laboratory personnel handling this compound must review the SDS before first use. The SDS contains authoritative information on hazard classification, first-aid measures, fire-fighting procedures, accidental release measures, and regulatory status.

GHS Hazard Classification: The specific GHS hazard classification for Cyclopentanone Oxime should be verified from the current SDS, as classification may vary between regulatory jurisdictions. Users are responsible for compliance with their local chemical safety regulations.

Transport: Shipping and transport classification (e.g., UN number, packing group) is detailed in Section 14 of the SDS. Ensure that any transport of this material complies with applicable IATA, IMDG, or road transport regulations. Aladdin Scientific ships products in accordance with applicable international and domestic shipping regulations.

Documentation for Procurement: Research institutions may require safety review documentation before a new chemical is approved for purchase. Prepare a preliminary hazard assessment using the SDS and confirm that appropriate storage and disposal facilities are available in your laboratory prior to ordering.

Frequently asked questions

What is the primary use of Cyclopentanone Oxime in organic synthesis?

Cyclopentanone Oxime is most commonly employed as a substrate for the Beckmann rearrangement, a reaction that converts ketoximes into lactams under acidic or photochemical conditions. The rearrangement of Cyclopentanone Oxime yields δ-valerolactam (2-azacyclohexanone), a lactam of interest both industrially and academically. It is also used as a ligand precursor in coordination chemistry and as an intermediate for further nitrogen-oxygen bond functionalization.

How should Cyclopentanone Oxime be stored to maintain stability?

Cyclopentanone Oxime should be stored in a tightly sealed container in a cool, dry, and well-ventilated area, away from heat sources, open flames, strong oxidizing agents, and strong acids. A storage temperature of 2–25 °C is generally recommended; however, researchers should consult the product-specific Safety Data Sheet and certificate of analysis for the precise conditions applicable to their lot. Avoid prolonged exposure to moisture and light.

Where can I find the Safety Data Sheet (SDS) and Certificate of Analysis (CoA) for Cyclopentanone Oxime (C138083)?

The Safety Data Sheet and Certificate of Analysis for Cyclopentanone Oxime (SKU: C138083) are available directly on the Aladdin Scientific product page for this item. If you cannot locate the documents online, please contact Aladdin Scientific customer service with your lot number and they will provide the relevant documentation promptly.

Can Cyclopentanone Oxime be used in coordination chemistry applications?

Yes, oximes including Cyclopentanone Oxime can act as neutral or anionic ligands toward transition metal centres, coordinating through the nitrogen or oxygen atoms of the C=N–OH group. Such complexes have been investigated for catalytic and materials applications. Researchers should consult the primary literature for specific complex preparation protocols, stability constants, and characterisation data, as these are not detailed in standard reagent supplier documentation.

What personal protective equipment is recommended when handling Cyclopentanone Oxime?

When handling Cyclopentanone Oxime, wear nitrile chemical-resistant gloves, a laboratory coat, and safety goggles or a face shield. All weighing and dissolution operations should be performed inside a well-ventilated fume hood to minimise inhalation exposure to dust or aerosols. Always consult the current Safety Data Sheet for comprehensive PPE recommendations specific to the hazard classification of the lot you are using.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley: New York, 1992. Chapter on Beckmann rearrangement.
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. Section on oximes and Beckmann rearrangement.
3. Aladdin Scientific. Product page: Cyclopentanone Oxime, SKU C138083. Retrieved from the Aladdin Scientific website.

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