2-(Methylthio)cyclohexanone: Properties, Uses & FAQs

2-(Methylthio)cyclohexanone is a sulfur-functionalized cyclic ketone used as a versatile intermediate in organic synthesis, enabling the introduction of a methylthio group alpha to a carbonyl within a six-membered ring scaffold.

Chemical Name

2-(Methylthio)cyclohexanone

CAS Number

3970-63-6

Molecular Formula

C7H12OS

Molecular Weight

144.23 g/mol

Functional Groups

Ketone (C=O) and thioether (C-S-CH3)

Aladdin SKU

B301280

Appearance

Liquid (expected based on structural analogs; verify with CoA)

What Is 2-(Methylthio)cyclohexanone?

2-(Methylthio)cyclohexanone (CAS 3970-63-6, MW 144.23 g/mol, molecular formula C₇H₁₂OS) is an alpha-substituted cyclohexanone bearing a methylthio (–SCH₃) group at the 2-position. The compound belongs to the broader class of beta-keto sulfides, in which a thioether is positioned alpha to a carbonyl. This arrangement confers dual reactivity: the carbonyl is available for nucleophilic addition, condensation, or enolization reactions, while the methylthio group can participate in electrophilic or oxidative transformations, or serve as a masked functionality that can be removed or elaborated.

The six-membered ring scaffold provides conformational rigidity relative to acyclic analogs, making this compound particularly useful when stereocontrol at the alpha carbon is desired. Aladdin Scientific supplies this compound under SKU B301280 for research and development applications.

Physical and Chemical Properties

2-(Methylthio)cyclohexanone contains a thioether and a ketone as its principal functional groups. Key physicochemical considerations include:

• Molecular Formula & Weight: C₇H₁₂OS; 144.23 g/mol.
• Polarity: The compound is moderately polar due to the carbonyl dipole, with the thioether contributing relatively modest polarity. It is expected to be soluble in common organic solvents such as dichloromethane, ethyl acetate, acetone, and THF.
• Reactivity at the alpha carbon: The alpha position bearing the methylthio group is activated toward enolate chemistry. The pKa of the alpha C–H is lowered by the combined electron-withdrawing influence of the adjacent carbonyl and the polarizable sulfur.
• Oxidation of sulfur: The thioether can be selectively oxidized to a sulfoxide or sulfone using peroxy acids or other oxidants, providing handles for further synthetic elaboration.
• Elimination potential: Under basic or acidic conditions, the methylthio group can be eliminated or substituted, offering routes to vinyl ketone derivatives or other functionalized cyclohexanones.

Note: Specific values for boiling point, density, refractive index, and flash point should be confirmed from the Aladdin Certificate of Analysis (CoA) for lot B301280, as these were not available in the current source material.

Synthesis and Laboratory Applications

2-(Methylthio)cyclohexanone can be prepared by alpha-sulfenylation of cyclohexanone. A common approach involves generating the enolate of cyclohexanone (using a strong base such as LDA or NaH) and treating it with a methylthiolating reagent (e.g., dimethyl disulfide or Mander's reagent analogs). Alternative routes include the conjugate addition of methanethiol to 2-cyclohexen-1-one.

In synthetic applications, this compound serves multiple roles:

• Building block for heterocycle synthesis: The alpha keto-sulfide motif is a common precursor to thiophene, dihydrothiophene, and related sulfur heterocycles via condensation or cyclization reactions.
• Masked enone equivalent: After oxidation of the sulfide to a sulfoxide, thermal elimination (Pummerer or related reactions) can generate 2-cyclohexen-1-one equivalents or other reactive intermediates.
• Stereoselective synthesis: The conformationally defined cyclohexanone ring allows asymmetric induction when chiral auxiliaries or catalysts are employed in subsequent transformations.
• Medicinal chemistry and natural product synthesis: The alpha-thio ketone fragment appears in various bioactive natural product cores, making this compound a useful synthetic intermediate.

Researchers should verify specific synthetic protocols in primary literature before use; application claims above are based on general reactivity principles of alpha-keto sulfides.

Safe Handling, Storage, and Regulatory Considerations

As with most thioether-containing organic compounds, 2-(Methylthio)cyclohexanone should be handled with standard laboratory precautions:

• Personal Protective Equipment (PPE): Wear appropriate gloves (nitrile recommended), safety glasses, and a lab coat. Work in a well-ventilated fume hood to avoid inhalation of vapors, which may have a characteristic sulfurous odor.
• Storage: Store in a tightly sealed container away from strong oxidizing agents, strong acids, and strong bases. Cool, dry storage conditions (typically 2–8 °C or room temperature under inert atmosphere, per CoA recommendation) are advised to prevent degradation.
• Waste Disposal: Dispose of in accordance with local, national, and institutional regulations for organic solvent and sulfur-containing compound waste.
• GHS/SDS: Consult the Safety Data Sheet (SDS) provided by Aladdin Scientific for SKU B301280 for complete hazard classification, first-aid measures, and regulatory information before use. SDS data takes precedence over general guidance provided here.

Specific GHS hazard categories, H-statements, and P-statements were not available in the source material and must be verified from the official SDS.

Ordering and Specifications

2-(Methylthio)cyclohexanone is available from Aladdin Scientific under the following details:

• SKU: B301280
• Product Name: 2-(Methylthio)cyclohexanone
• CAS Number: 3970-63-6
• Purity / Grade: Please refer to the current product listing on the Aladdin Scientific website or contact customer service for available purity grades, pack sizes, and pricing.
• Certificate of Analysis (CoA): Available upon request or via the Aladdin Scientific product page by lot number.
• Lead Time & Shipping: Standard stock items ship according to Aladdin Scientific's current fulfillment schedule. For bulk quantities or custom purity requirements, contact Aladdin Scientific sales.

For questions regarding specifications, minimum order quantities, or regulatory documentation (e.g., REACH, export compliance), contact Aladdin Scientific customer service directly.

Frequently asked questions

What is the CAS number and molecular formula of 2-(Methylthio)cyclohexanone?

The CAS number is 3970-63-6 and the molecular formula is C7H12OS, giving a molecular weight of 144.23 g/mol. The structure consists of a cyclohexanone ring with a methylthio (–SCH3) substituent at the alpha (2) position.

What are the main synthetic uses of 2-(Methylthio)cyclohexanone in the laboratory?

It is primarily used as an alpha-keto sulfide building block in organic synthesis. Key applications include heterocycle construction (e.g., thiophene and dihydrothiophene synthesis), as a masked enone precursor via sulfoxide elimination, and as a stereoselective synthesis intermediate taking advantage of the conformationally defined cyclohexanone ring. It also appears as a fragment in natural product and medicinal chemistry syntheses.

How should 2-(Methylthio)cyclohexanone be stored to maintain stability?

Store in a tightly sealed container, away from strong oxidizing agents, strong acids, and strong bases. Cool and dry conditions are generally recommended for thioether ketone compounds. Always refer to the Aladdin Scientific SDS and Certificate of Analysis for lot-specific storage instructions, as these supersede general guidance.

Can the methylthio group in 2-(Methylthio)cyclohexanone be selectively oxidized?

Yes. The thioether sulfur can be selectively oxidized to a sulfoxide using reagents such as meta-chloroperoxybenzoic acid (mCPBA) or similar peracids under controlled conditions, without oxidizing the ketone carbonyl. Further oxidation to the sulfone is achievable with excess oxidant. The sulfoxide product is useful for subsequent Pummerer reactions or thermal eliminations.

Where can I find the Safety Data Sheet (SDS) and Certificate of Analysis (CoA) for Aladdin SKU B301280?

The SDS and CoA for B301280 are available directly on the Aladdin Scientific product page for this SKU. You can also contact Aladdin Scientific customer service by email or phone to request these documents. Always check the lot-specific CoA to confirm purity, physical constants, and storage requirements for your received batch.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley: New York, 1992. (General reference for alpha-keto sulfide reactivity and enolate chemistry.)
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (Reference for thioether oxidation and sulfoxide elimination reactions.)
3. Aladdin Scientific. Product page and Safety Data Sheet for 2-(Methylthio)cyclohexanone, SKU B301280. Aladdin Scientific Corp.

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