2-Methylpentane-2-thiol - ≥95% , CAS No.1633-97-2

CAS: 1633-97-2 Cat. No.: M1055212 Formula: C₆H₁₄S Molecular Weight: 118.240 EC Number: EINECS216-651-0

GRADE & PURITY ≥95%

Storage

Room temperature

Specifications

Specifications & Purity

≥95%

Storage

Room temperature

Purity

≥95%

Names and Identifiers

• Canonical Smiles: CCCC(C)(C)S
• IUPAC Name: 2-methylpentane-2-thiol
• InChIKey: ISUXQQTXICTKOV-UHFFFAOYSA-N
• INCHI: 1S/C6H14S/c1-4-5-6(2,3)7/h7H,4-5H2,1-3H3
• Molecular Weight: 118.240

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organosulfur compounds
    • Class Thiols
      • Subclass Alkylthiols

• Kingdom: Organic compounds
• Superclass: Organosulfur compounds
• Class: Thiols
• Subclass: Alkylthiols
• Intermediate Tree Nodes: Not available
• Direct Parent: Alkylthiols
• Alternative Parents: Hydrocarbon derivatives
• Molecular Framework: Aliphatic acyclic compounds
• Substituents: Alkylthiol - Hydrocarbon derivative - Aliphatic acyclic compound
• Description: This compound belongs to the class of organic compounds known as alkylthiols. These are organic compounds containing the thiol functional group linked to an alkyl chain.
• External Descriptors: Not available

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Chemical and Physical Properties

• Molecular Weight: 118.240 g/mol
• XLogP3: 2.400
• Hydrogen Bond Donor Count: 1
• Hydrogen Bond Acceptor Count: 1
• Rotatable Bond Count: 2
• Exact Mass: 118.082 Da
• Monoisotopic Mass: 118.082 Da
• Topological Polar Surface Area: 1.000 Ų
• Heavy Atom Count: 7
• Formal Charge: 0
• Complexity: 48.100
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 0
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

No standardized bioassay or immunoassay protocols apply to this small-molecule reagent. For synthetic applications, see Reaction Conditions and Synthetic Utility for general literature procedures. Always tailor stoichiometry, solvent, and temperature to your specific substrates and perform small-scale trials before scale-up.

Biological Roles

Applicability note: 2-Methylpentane-2-thiol is a synthetic aliphatic thiol and is not known to occur naturally or play a physiological role.

General biochemical context (literature)

• Thiol functionality: In biology, thiols (e.g., cysteine, glutathione) are central to redox homeostasis, metal coordination, and enzyme catalysis. The S–H moiety can undergo reversible oxidation (disulfide formation) and participate in radical and nucleophilic processes.
• Model compound usage: Aliphatic thiols are sometimes used as simplified models to study thiol reactivity, radical chain-transfer kinetics, or adsorption of sulfur species on metal surfaces (e.g., Au, Ag) in surface science.

Limitations and cautions

• No known metabolic or signaling function specific to 2-methylpentane-2-thiol has been established. Any biological experimentation should be conducted strictly for research use, not for diagnostic or therapeutic applications (per Research Use Note).

Buffer Applications

Not typically applicable. 2-Methylpentane-2-thiol is a hydrophobic reagent and is not used to prepare aqueous buffer systems. For experiments requiring this thiol, select an appropriate organic solvent system (see Solvent Selection) and, if interfacing with aqueous media, consider biphasic or micellar catalysis approaches from the literature.

Green Alternatives

Context: While the thiol itself is the reagent of interest, greener decisions can be made around solvent selection, odor management, and surrogate use to reduce emissions and exposure.

Options and trade-offs (literature/guidance)

• Greener solvents for thiol chemistry: Prefer 2-MeTHF or CPME over THF/MTBE; ethyl acetate or toluene over chlorinated solvents when feasible. Maintain inert conditions to limit oxidative byproducts.
• Odor-masked surrogates: Use thioacetates or protected thiols (e.g., S-acetyl tert-hexyl) that can be deprotected in situ, reducing volatile thiol release. Trade-off: extra step and reagents.
• Process intensification: Conduct thiol–ene reactions in flow with UV LEDs to minimize headspace and odor; improves EHS and scalability.
• Waste minimization: Oxidatively neutralize residual thiol in aqueous wastes with alkaline hypochlorite, then reduce AOX formation by controlling dose and pH; confirm by TOC/halogen analysis if regulated.

Compact comparison

• 2-MeTHF/CPME: Renewable/safer, broad solubility; may form peroxides over time—monitor.
• Ethyl acetate: Low toxicity, biodegradable; limited base compatibility.
• Toluene: Good for radical additions; higher VOC burden vs esters.
• Thioacetate surrogate: Lower odor; requires deprotection step and generates acetate waste.

Pharmaceutical Uses

No pharmacopeial or excipient role is specified for this item; refer to CoA/Spec Sheet if a compendial status is required.

Context (literature/generic)

• In pharmaceutical process chemistry, low-MW thiols can serve as transient blocking groups, chain-transfer agents, or sulfur donors in intermediates synthesis. Their strong odor and potential impurity carryover demand robust purge strategies and analytical controls (GC-SCD/FPD).
• Due to odor and safety considerations, direct use in formulated drug products is uncommon. Any use would be at the intermediate/reagent stage under GMP controls, not as an active or excipient.

Physical Properties

Item-specific specs

• Any numerical specifications (bp, density, refractive index, water, UV cutoff, metals, etc.): Not specified for this item; refer to CoA/Spec Sheet.

Literature and general reference values (not item specifications)

• Physical state: Colorless to pale yellow, high-odor liquid typical of low-MW thiols (literature, general for aliphatic thiols)
• Boiling point: ~118–121 °C at 1 atm (literature for tert-hexyl mercaptan)
• Melting point: Approximately −80 to −60 °C (literature, approximate for analogous tertiary thiols)
• Density: ~0.83–0.86 g/mL at 20–25 °C (literature range)
• Refractive index (n20 D): ~1.440–1.450 (literature range)
• pKa (thiol S–H): ~10.5–11.0 in water; ~16–18 in DMSO (literature, tertiary thiols slightly less acidic than primary)
• LogP: Expected positive (hydrophobic), estimated ~2.0–2.8 (literature/estimations for C6 alkanethiols)
• Solubility: Insoluble in water; miscible with many nonpolar/aprotic organic solvents (hexanes, toluene, ethers, chlorinated solvents) (literature)

Notes for practitioners

• Odor threshold extremely low; trace contamination may be noticeable.
• Vapor is heavier than air; ensure effective local exhaust when heating or distilling.
• Values above are typical literature ranges to aid planning; consult CoA for this batch’s reportable specs if required.

Quality & Grades

Item-specific

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers: Not specified for this item; refer to CoA/Spec Sheet.

Guidance for this compound class (thiols)

• Typical research grades: Neat reagent grade (assay usually by GC); sometimes supplied with trace inhibitor/antioxidant to limit air-oxidation to disulfides. Low-peroxide specs are generally not applicable to thiols (more relevant to ethers), but oxidative impurities (disulfides) may be reported by GC.
• Chromatography compatibility: For demanding applications (e.g., analytical derivatization), low-UV-absorbing solvent residues and tight GC assay are preferred.
• Odor management in QC: Headspace GC and sulfur-specific detectors (e.g., FPD, SCD) can quantify sulfur volatiles and disulfides.

What to check on the CoA for your use case

• Assay by GC (%), identity confirmation (GC-MS/1H NMR), residual solvents, acidity (as mg KOH/g) if relevant, sulfur oxidation state impurities (disulfides), and water by Karl Fischer if moisture-sensitive reactions are planned. If your process is air-sensitive, confirm packaging under inert atmosphere.

Reaction & Applications

Literature and practitioner-focused uses (not item specifications)

• Nucleophilic substitution to form thioethers: Deprotonation (NaH, K2CO3, or TMG/DBU) generates the tert-hexyl thiolate, which reacts with primary alkyl halides/mesylates under SN2. Tertiary substrate is hindered only at sulfur; the leaving group substrate should be unhindered for efficient SN2.
• Thiol–ene/thiol–yne click chemistry: Under radical initiation (AIBN, peroxides, photoinitiators) or UV light, adds across alkenes/alkynes to give anti-Markovnikov thioethers with high functional tolerance.
• Radical chain-transfer agent: The weak S–H bond (BDE ~87–90 kcal/mol, literature) and stability of thiyl radicals enable control of radical polymerization (Mayo mechanism) to adjust molecular weight and end-groups.
• Oxidation chemistry: Readily oxidized to the disulfide (air, I2, H2O2 under controlled conditions). Further oxidation (sulfinyl/sulfonyl) requires stronger oxidants and caution to avoid over-oxidation.
• Protection/derivatization: Conversion to S-acetyl or thioester derivatives for odor masking and subsequent deprotection; formation of sulfenyl chlorides (RSCl) for electrophilic sulfur transfer.

Practical tips

• Odor control: Use septa and closed systems; quench residues with oxidizing bleach solution (pH >9) to destroy thiol odor.
• Base choice: K2CO3 suffices for many alkylations in polar aprotics; stronger bases (NaH) increase rates but require strict anhydrous technique.
• Hindered reagents: As a tertiary thiol, steric bulk can modestly reduce rates in crowded transition states; elevate temperature or choose more reactive electrophiles where needed.

Reaction Conditions

General literature guidance (typical; adjust per substrate and scale)

• SN2 alkylation to form thioethers:
  • Base/solvent: K2CO3 (2–3 equiv) in MeCN or acetone, or NaH (1.1–1.5 equiv) in DMF/THF.
  • Electrophiles: Primary halides/mesylates (1.0–1.2 equiv).
  • Temperature/time: 20–60 °C, 2–16 h.
  • Notes: Exclude water/oxygen; tertiary substrates or secondary halides may lead to elimination/low yields.
• Thiol–ene addition:
  • Initiation: AIBN (5–10 mol%) at 60–80 °C in toluene; or photoinitiation (365–405 nm LEDs) with 1–2 mol% Type I photoinitiator (e.g., DMPA) at rt–40 °C.
  • Stoichiometry: Alkene 1.0 equiv; thiol 1.1–1.5 equiv.
  • Atmosphere: Nitrogen/argon; oxygen inhibits radicals.
  • Expected outcomes: High anti-Markovnikov selectivity; near-quantitative conversions in 1–6 h on activated alkenes (literature).
• Oxidation to disulfide (RSSR):
  • I2 (0.5 equiv) in MeOH/DCM at 0–25 °C; or air/O2 with catalytic base (TEA) in alcohol.
  • Workup: Sodium thiosulfate to quench iodine and reduce odor.

Analytical/handling tips

• Monitor by GC-FID/GC-MS due to volatility and odor; 1H NMR shows characteristic broad S–H signal (often δ 1–2 ppm, solvent-dependent) that disappears on alkylation/oxidation.
• Use PTFE-lined caps and crimp vials to contain volatiles during reactions and sampling.

Safety & Handling

Item-specific hazard info from Product Data

• Signal word/GHS class/H-statements/Pictograms: Not specified for this item; refer to the SDS.

General safety profile for low-molecular-weight aliphatic thiols (literature; consult SDS for authoritative classification)

• Hazards: Flammable liquid/vapor; acute toxicity/irritation possible via inhalation, skin, and eyes; strong, pervasive odor. Thiols can cause headaches/nausea at low concentrations.
• Incompatibilities: Strong oxidizers (risk of exothermic reaction/oxidation to disulfides), strong bases (rapid deprotonation to thiolates), acids (corrosion), and nitrating agents. Avoid air/oxygen during storage to limit oxidation.
• PPE: Chemical-resistant gloves (e.g., nitrile), lab coat, splash goggles; use in fume hood. For bulk transfers, consider face shield and respiratory protection per risk assessment.
• First aid (overview; defer to SDS):
  • Inhalation: Move to fresh air; seek medical attention if symptoms persist.
  • Skin: Wash with soap/water; remove contaminated clothing.
  • Eyes: Rinse with water for 15 minutes; obtain medical attention.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical advice.
• Handling tips: Minimize headspace and exposure pathways to control odor; use septum-sealed syringes for transfers. Ground/bond during bulk dispensing. Control static.
• Special risks: Readily oxidizes to disulfide; add antioxidant or store under inert gas if oxidation-sensitive use is anticipated. Spills can impart persistent odor—absorbents with oxidants (e.g., hypochlorite, permanganate) can help chemically neutralize thiol odor, following institutional procedures.

Solvent Selection

Applicability note: 2-Methylpentane-2-thiol is a reagent, not typically used as a bulk solvent. This section addresses solvent choice for reactions involving this thiol.

General solvent compatibility (literature)

• Polarity: Nonpolar to weakly polar substrate; readily soluble in hydrocarbons (hexane, heptane), ethers (MTBE, THF, CPME), and chlorinated solvents (DCM). Poorly soluble in water and highly polar protic media.
• Dielectric compatibility: Performs well in low-to-moderate dielectric solvents; thiolate generation/alkylation often benefits from polar aprotics (DMF, DMSO, MeCN) when using inorganic bases.

Choosing a solvent by transformation

• SN2 thioether formation: MeCN, DMF, DMSO, or acetone with K2CO3/NaH; ether/hydrocarbon co-solvent may help dissolve alkyl halides.
• Thiol–ene/thiol–yne click: Nonpolar solvents (toluene, heptane) or bulk conditions; oxygen exclusion improves control.
• Radical chain transfer (Mayo): Bulk polymerizations or solution in toluene/ethyl acetate; viscosity control is important.
• Oxidation to disulfide: Alcohols or MeOH/DCM mixtures with mild oxidants (I2, air with catalytic base). Avoid over-oxidation with strong oxidants in polar media.

Comparison notes

• Hydrocarbons: Easiest odor management; fastest workups; lowest polarity for SN2.
• Ethers (2-MeTHF/CPME): Greener choice vs THF; good balance of solubility and handling.
• Polar aprotics: Best for generating thiolates; ensure proper PPE due to co-solvent toxicity.

Storage & Reconstitution

Item-specific

• Storage conditions: Room temperature (per Product Data).
• Shipped in: Not specified for this item; refer to CoA/Spec Sheet.

General handling guidance for aliphatic thiols (literature/practice)

• Container: Store tightly sealed in compatible glass with PTFE-lined cap to minimize permeation and odor.
• Atmosphere: If long-term storage is anticipated, blanket with nitrogen/argon to limit oxidation to disulfides; addition of a trace antioxidant is sometimes used in industry, but no stabilizer is specified for this item.
• Light/moisture: Protect from strong light and moisture ingress. Keep away from oxidizers and bases.
• Temperature: Ambient is acceptable; cooler storage (e.g., 2–8 °C) can further limit vapor pressure and oxidation but may increase viscosity.
• Freeze–thaw: Not applicable; the product is supplied neat (no reconstitution required).
• Disposal: Quench small residues by careful oxidation in alkaline hypochlorite solution, then follow institutional hazardous waste procedures.

Research use note

• For research use only. Not for human or veterinary use.

Structure & Identity

Item-specific (from Product Data)

• Product name: 2-Methylpentane-2-thiol (SKU: M1055212)
• CAS: 1633-97-2
• InChIKey: 149638 (as provided; truncated/not standard format in listing)
• Storage: Room temperature
• Category path: 全部 / 可售 / 生命科学
• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• Appearance: Not specified for this item; refer to CoA/Spec Sheet.

Literature identity (for reference; not item specifications)

• Synonyms: tert-Hexyl mercaptan; 2-methyl-2-pentanethiol
• Molecular formula: C6H14S (literature)
• Molecular weight: ~118.24 g/mol (literature)
• SMILES: CC(C)(CC)S (literature)
• Structural features: A tertiary thiol (mercaptan) at the 2-position of a 2-methylpentane skeleton. The sulfur is attached to a tertiary carbon bearing two methyl/alkyl substituents (one methyl and one n-propyl fragment), conferring significant steric hindrance and reduced acidity compared with primary/secondary thiols.

2D description (general)

• Backbone: Branched C6 aliphatic chain with a quaternization-like center (tertiary carbon) bearing –SH.
• Functional group(s): Thiol (–SH) capable of nucleophilic and radical chemistry; prone to oxidation to disulfides (RSSR).

Synthetic Utility

Functional group leverage (literature)

• Nucleophilicity: Thiolate (RS−) formed from 2-methylpentane-2-thiol is a potent soft nucleophile for SN2 substitutions on primary alkyl electrophiles, giving sterically bulky thioethers that can modulate lipophilicity and steric environment in ligands.
• Radical chemistry: The S–H bond readily participates in chain-transfer and thiol–ene additions, enabling end-group control in radical polymerization and efficient hydrothiolation of alkenes/alkynes.
• Redox versatility: Oxidation to disulfides offers reversible “dimerization” handles; further oxidation to sulfoxides/sulfones (via thioether intermediates) expands oxidation-state space.
• Electrophilic sulfur transfer: Through sulfenyl halides or N-thiosuccinimide derivatives, tert-hexylthio (tHexS–) can be introduced onto nucleophiles, providing a bulky, lipophilic S-protecting or modulating group.

Retrosynthetic considerations

• The tert-hexylthio group can act as a temporary handle to tune conformation or block reactive sites; it may be cleaved under reductive (Raney Ni desulfurization for thioacetals/thioethers) or oxidative conditions depending on context.
• Steric effects: Tertiary substitution at sulfur-adjacent carbon reduces β-elimination risks in some settings and can improve selectivity in multi-substitution sequences.

Target Specificity

Not applicable. This product is a small-molecule thiol reagent and has no antibody/biomolecule target specificity. No clone/isotype/epitope information applies.