Heptane-4-thiol - ≥95% , CAS No.1639-06-1

CAS: 1639-06-1 Cat. No.: H985650 Formula: C₇H₁₆S Molecular Weight: 132.270

GRADE & PURITY ≥95%

Storage

Room temperature

Specifications

Specifications & Purity

≥95%

Storage

Room temperature

Purity

≥95%

Names and Identifiers

Canonical Smiles

CCCC(CCC)S

IUPAC Name

heptane-4-thiol

InChIKey

OPLGIZOGDFCNCU-UHFFFAOYSA-N

INCHI

1S/C7H16S/c1-3-5-7(8)6-4-2/h7-8H,3-6H2,1-2H3

Molecular Weight

132.270

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: 132.270 g/mol
• XLogP3: 3.100
• Hydrogen Bond Donor Count: 1
• Hydrogen Bond Acceptor Count: 1
• Rotatable Bond Count: 4
• Exact Mass: 132.097 Da
• Monoisotopic Mass: 132.097 Da
• Topological Polar Surface Area: 1.000 Ų
• Heavy Atom Count: 8
• Formal Charge: 0
• Complexity: 37.700
• 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 item-specific tested applications are provided. As a general chemical reagent, usage protocols depend on the transformation:

• S-Alkylation (general): Dry glassware and solvent. Form thiolate with base (e.g., NaH in THF at 0 °C), then add electrophile. Monitor by TLC/GC. Quench with NH4Cl, extract, dry, and purify.
• Thiol–ene photochemistry: Combine alkene, thiol, and photoinitiator in degassed solvent; irradiate at 365–405 nm with stirring under N2; monitor by GC/MS.
• SAM preparation on Au: Prepare 0.1–1 mM ethanolic solution of the thiol; immerse freshly cleaned gold substrate under inert atmosphere for several hours; rinse with ethanol and dry under N2.

Please tailor conditions to your substrate and consult primary literature/SDS. For any regulated use, establish and validate your own SOPs.

Biological Roles

Item-specific biological/biochemical roles: Not specified for this item; this product is supplied for research use only.

General context (biochemistry of thiols; not specific to heptane-4-thiol as a metabolite):

• Thiol functionality (–SH) is central in biology (e.g., cysteine, glutathione) for redox homeostasis, metal binding, and enzymatic catalysis. However, simple hydrophobic alkanethiols like heptane-4-thiol are not endogenous metabolites and have no established physiological role.
• Reactivity with proteins: Low-molecular-weight thiols can undergo thiol–disulfide exchange or add to activated electrophiles (e.g., Michael acceptors). In biological matrices, such reactivity can lead to nonspecific modification of cysteine residues.
• Membrane interaction: Hydrophobic thiols can partition into lipid phases due to high hydrophobicity, but specific binding/transport mechanisms are not described for this compound.
• Analytical uses: Alkanethiols are occasionally used as model nucleophiles or odorant standards in sensory research, but such applications must be evaluated case-by-case and are outside the scope of any clinical/therapeutic use.

Important: No medical, diagnostic, or therapeutic uses are claimed or implied. Handle exclusively as a laboratory chemical.

Buffer Applications

Not typically applicable. Heptane-4-thiol is a hydrophobic organic reagent and is not used to formulate aqueous buffer systems. If your work involves biochemical modification (e.g., thiol–maleimide reactions) in buffered media, prepare the thiol stock in a compatible organic cosolvent (e.g., DMSO or MeCN), then add to the aqueous buffer under inert atmosphere and minimal headspace to limit oxidation.

General tips when interfacing with buffers:

• Maintain pH near 7–8 for maleimide coupling to minimize hydrolysis while preserving thiol nucleophilicity; avoid strong base which forms thiolate and can increase odor and side reactions.
• Degas buffers (argon sparge) and include reducing agents only if compatible with downstream steps; note that common reductants (DTT/TCEP) can compete with your thiol chemistry.

Green Alternatives

While the intrinsic functionality of heptane-4-thiol is often required, you can improve process greenness by solvent and process choices, and by odor/volatility management.

• Solvent greening:
  • Replace THF/diethyl ether with 2-MeTHF or CPME for S-alkylations and radical additions; these solvents offer better safety profiles and often enable easier phase separation.
  • Use EtOAc, MeCN, or green alcohols (EtOH, iPrOH) where compatible, especially for SAM preparation and Michael additions.
• Protected thiol surrogates:
  • Employ thioacetates or disulfides as less odorous, more stable intermediates, then unmask the thiol in situ (e.g., hydrolysis or reduction). This reduces fugitive odor and potential emissions.
• Energy and waste:
  • Photochemical thiol–ene under LED irradiation at ambient temperature minimizes heating and can proceed neat or at high solids, reducing solvent use.
• Comparison snapshot (general):
  • THF vs 2-MeTHF: similar polarity and performance; 2-MeTHF is bio-derived and has higher boiling point (easier recovery), but can contain peroxides—monitor and manage.
  • DCM vs EtOAc: DCM offers excellent solvation but has higher environmental/health concerns; EtOAc is greener and often a viable replacement for extractions and some reactions.
• Odor and emissions control:
  • Use sealed reactors, cold traps, and activated-carbon scrubbing for vents. Adopt odor-absorbing waste streams to minimize environmental impact.

Trade-offs: Some greener solvents may alter rates/selectivity; perform small-scale screenings to confirm parity.

Pharmaceutical Uses

Item-specific pharmacopeial status, excipient role, or GMP applicability: Not specified for this item; refer to CoA/Spec Sheet.

General considerations (non-clinical, formulation/process context only):

• Alkanethiols are not common pharmaceutical excipients due to odor, reactivity, and sensitization potential. Heptane-4-thiol is primarily a research/synthetic intermediate.
• Possible roles in process R&D:
  • Synthetic intermediate for thioether-containing building blocks.
  • Surface modification (e.g., Au-thiol SAMs) in sensor components used in device R&D (not drug product excipients).
  • Chain-transfer agent in polymer production for specialty materials (e.g., medical device components) where residual monomer specifications are tightly controlled.

No therapeutic, diagnostic, or clinical applications are claimed. Any cGMP or regulatory use would require independent qualification and specification setting.

Physical Properties

Item-specific specifications: Not specified for this item; refer to CoA/Spec Sheet.

General/literature information for heptane-4-thiol (for reference only; not item specifications):

• Physical state: typically a colorless to pale yellow, strongly odorous liquid (alkanethiols are notable for intense odors).
• Approximate boiling point: secondary alkanethiols of C7 chain length commonly boil in the ~175–190 °C range (literature, compound-class trend; exact value depends on isomer and purity).
• Melting point: expected below 0 °C for C7 thiols (literature trend for similar alkanethiols); specific value not established here.
• Density: alkanethiols in the C6–C8 range typically show densities ~0.82–0.86 g/mL at 20–25 °C (literature trend); exact density for this isomer not provided.
• Refractive index: typically around n20/D 1.44–1.46 for C7 alkanethiols (literature range); item-specific value not provided.
• Solubility: sparingly soluble in water; miscible with nonpolar organic solvents (hexanes, toluene) and soluble in moderately polar aprotic solvents (THF, DCM, EtOAc) (general behavior of alkanethiols).
• Vapor pressure/odor: volatile enough to produce persistent odor at room temperature; handle in well-ventilated hoods (general property of low-molecular-weight thiols).
• pKa (S–H): thiols typically pKa ~9–11; secondary alkanethiols commonly near 10 (literature generalization).
• LogP: aliphatic C7 thiols generally exhibit logP in the mid-3 range (literature estimates); specific measured value not provided.

Always consult the product’s CoA/Spec Sheet for definitive physical data for this specific lot.

Quality & Grades

Item-specific grade/purity, stabilizers, and analytical limits: Not specified for this item; refer to CoA/Spec Sheet.

Guidance for evaluating alkanethiol quality (general information for professional users):

• Typical quality markers: assay by GC (>95–98% for many research grades), GC profile (minor isomers/impurities), residual solvents, acidity (as acetic acid equivalents), and oxidation state (disulfide content). For thiols, the presence of the corresponding disulfide is a common aging impurity.
• UV/Vis background: Not usually a key specification unless thiol is intended for photochemical studies; background absorbance is typically low above 220 nm.
• Odor stabilizers: Not common. Antioxidant stabilization is sometimes used for sensitive thiols, but specifics must be confirmed on the CoA.
• What a grade means (general):
  • Research grade: suitable for general synthesis and lab R&D. Assay and key impurities are reported on CoA.
  • Purified/Distilled grade: tighter control of GC purity and water; may be dispensed under inert gas to minimize oxidation.
  • Custom specs: For surface-assembly or trace-metal–sensitive applications, low-metal and low-oxygen packaging may be offered on request.

Recommendations:

• On receipt, verify GC purity and disulfide content if your application is oxidation-sensitive (e.g., SAMs formation or radical chain-transfer calibration).
• If ultra-low odor during handling is critical, consider using protected precursors (e.g., thioacetates) with in situ deprotection, or use dedicated odor containment protocols.

Reaction & Applications

Heptane-4-thiol is a versatile nucleophile and radical donor used across organic synthesis and surface chemistry.

• Nucleophilic S-alkylation/SN2:
  • Deprotonate with NaH, NaOMe/NaOEt, K2CO3, or stronger bases to form the corresponding secondary thiolate, then react with primary alkyl halides, mesylates, or tosylates to form thioethers (sulfides). Secondary/tertiary electrophiles favor elimination or SN1 pathways; adjust conditions accordingly.
• Thiol–ene (radical) addition:
  • Anti-Markovnikov addition across terminal alkenes under photochemical (365–405 nm with Type I/II photoinitiators) or thermal radical initiation (AIBN, peroxides). Useful for late-stage installation of the C7 thioalkyl fragment.
• Conjugate (Michael) additions:
  • Adds to activated alkenes (acrylates, acrylamides, maleimides) under base or nucleophilic catalysis to give thioether adducts with high efficiency at ambient temperature.
• Disulfide formation/cleavage:
  • Air or mild oxidants (I2, H2O2, FeCl3) dimerize to the disulfide; reductants (DTT, TCEP, NaBH4) regenerate thiol. This redox pair can be leveraged in protecting-group strategies or dynamic covalent chemistry.
• Surface chemistry:
  • Alkanethiols chemisorb on coinage metals (Au, Ag, Cu) via Au–S, etc., forming self-assembled monolayers (SAMs). C7 provides intermediate chain length balancing packing and mobility.
• Polymer chemistry:
  • Functions as a chain-transfer agent in free-radical polymerizations to control molecular weight and end-group functionality.

Practical tips:

• Control odor and oxidation by working under inert atmosphere and minimizing headspace. Monitor for disulfide by GC.
• For SN2: use dry, polar aprotic solvent; add electrophile slowly to the preformed thiolate to suppress side reactions.
• For thiol–ene: remove O2 (degassing) to avoid radical quenching.

Reaction Conditions

General literature guidance (not item-specific; optimize for your substrate set):

• S-Alkylation (SN2 to form thioethers):
  • Typical: Heptane-4-thiol (1.0 eq), NaH (1.05–1.2 eq) in dry THF or DMF, 0 °C to rt; add primary alkyl halide or sulfonate (1.0–1.2 eq) dropwise; 1–4 h. Quench cautiously, work up, purify by column. Bases like K2CO3 in MeCN or acetone are milder alternatives (longer times).
• Thiol–ene addition:
  • Photochemical: Alkene (1.0 eq), thiol (1.1–1.5 eq), photoinitiator (e.g., 0.5–2 mol% DMPA or Ir(ppy)3), solvent (MeCN, EtOAc, toluene), N2 purge, 365–405 nm LED, rt, 0.5–4 h. Thermal initiation: AIBN (5–10 mol%) at 60–80 °C in toluene or xylene.
• Michael addition to acrylates/maleimides:
  • Base-catalyzed: Thiol (1.0 eq), Michael acceptor (1.0–1.2 eq), 5–20 mol% DBU/TEA in MeCN/MeOH/DCM; rt, 0.5–2 h; often near-quantitative by NMR.
• Oxidation to disulfide:
  • I2 (0.5 eq) in MeOH or DCM at 0 °C to rt gives the symmetrical disulfide rapidly; quench excess iodine with sodium thiosulfate.
• SAM formation on gold:
  • 0.1–1.0 mM thiol in absolute EtOH or iPrOH, immerse clean Au for 1–24 h under N2; rinse with solvent; dry under N2. Work in low-oxygen/low-light conditions to limit over-oxidation.

Notes:

• Remove dissolved oxygen by freeze–pump–thaw or N2/Ar sparging prior to radical reactions.
• Maintain anhydrous conditions for base-mediated steps. Verify conversions by GC or 1H NMR (thiol S–H singlet typically broad and downfield, ~1–2 ppm region can be weak; monitor adjacent methine/methylene shifts).

Safety & Handling

Item-specific GHS details: Not specified for this item; refer to SDS.

General safety guidance for alkanethiols (for reference; defer to SDS for authoritative instructions):

• Hazards: Flammable liquid and vapor; harmful if inhaled; causes skin and eye irritation; may cause skin sensitization in susceptible individuals. Strong, persistent odor can indicate very low airborne concentrations.
• Odor control: Even trace contamination can odorize large areas. Work exclusively in a certified chemical fume hood. Keep containers tightly closed; wipe threads and exterior surfaces after dispensing.
• PPE: Lab coat, nitrile gloves (change frequently due to odor permeation), splash goggles. Consider double-gloving for extended handling. Use odor-adsorbing waste containers (activated carbon) where permitted.
• Incompatibilities: Strong oxidizers (thiols oxidize to disulfides), strong bases/acids (can accelerate oxidation or decompose depending on conditions), and soft-metal salts (thiolate formation/coordination). Avoid contact with halogens.
• Reactivity: Air oxidation to the disulfide is common over time, especially with light/air exposure. Not prone to peroxide formation like ethers, but oxidation is still a consideration.
• First aid (overview; refer to SDS):
  • Inhalation: Move to fresh air; seek medical advice if symptoms persist.
  • Skin: Wash with soap and water; remove contaminated clothing.
  • Eyes: Rinse cautiously with water for several minutes; remove contact lenses if easy; seek medical attention if irritation persists.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical attention.
• Spill response: Contain and absorb with inert material; transfer to sealed, odor-tight container. Decontaminate with oxidizing bleach solution only if compatible with surroundings and waste rules; verify local procedures.
• Fire-fighting: Use foam, dry chemical, or CO2. Cool containers with water spray. Combustion may release sulfur oxides.

Solvent Selection

This product is a reactive alkanethiol reagent rather than a general-purpose solvent. Solvent selection below pertains to its use in synthesis and processing.

• Polarity/miscibility profile (general):
  • Hydrophobic, low polarity. Miscible with nonpolar organics (hexanes, heptane, toluene) and soluble in moderately polar aprotic solvents (DCM, THF, EtOAc). Very low solubility in water.
• Choosing media for reactions:
  • Nucleophilic substitutions (S-alkylations): Use polar aprotic solvents (DMF, DMSO, MeCN) or THF with a base (e.g., NaH, K2CO3) to generate thiolate; ensure anhydrous conditions.
  • Thiol–ene/thiol–yne additions: Employ solvents of suitable transparency for photolysis (e.g., MeCN, EtOAc, toluene) or run neat if viscosity allows.
  • Michael additions to acrylates/maleimides: Mildly polar solvents (MeOH, MeCN, DCM) with base or nucleophilic catalysts (e.g., DBU, TBD, tertiary amines).
  • SAM formation on Au: Ethanol or isopropanol (water-free) often used to dissolve thiol before immersion of gold substrates.
• Practical notes:
  • Avoid strongly basic aqueous media if odor control is a concern; thiolates are even more odorous and can volatilize.
  • Degas and dry solvents to limit oxidative dimerization to disulfides.
• Comparisons:
  • Hexane/heptane: best for extractions or nonpolar workup; minimal polarity.
  • THF/MeCN: enhance reaction rates for S-alkylation and Michael additions via better solvation of ions but require stringent drying.
  • 2-MeTHF or CPME: greener alternatives to THF/ether for many transformations with comparable performance.

Storage & Reconstitution

Item-specific storage: Room temperature (per Product Data). Shipped conditions: Not specified for this item; refer to CoA/Spec Sheet.

General storage guidance for alkanethiols:

• Keep tightly sealed in original container to minimize odor emissions and air ingress. Store in a cool, well-ventilated area away from oxidizers and ignition sources.
• To preserve thiol content (limit disulfide formation), consider storing under inert gas (N2/Ar) and protecting from light. For long-term storage, an amber bottle with minimal headspace is recommended.
• If cold temperatures cause viscosity increase or partial solidification, allow to warm gently to ambient before use; mix thoroughly to ensure homogeneity.
• Do not store near bases or acids that could catalyze side reactions; avoid contact with metals that can promote oxidation.

Reconstitution: Not applicable (typically supplied as a neat liquid). If dilution is desired for stock solutions, prepare under inert atmosphere using dry, compatible solvents (e.g., hexane, toluene, EtOH, THF, MeCN) and store solutions in sealed vials; label with preparation date and solvent.

Inspection on receipt and prior to use: Check for discoloration or crystalline deposits; analyze by GC if critical. The odor intensity alone is not a reliable purity indicator. Refer to the CoA/SDS for lot-specific guidance.

Research Use Note: For research use only.

Structure & Identity

Heptane-4-thiol (also called 4-mercaptoheptane) is a secondary alkanethiol featuring a seven-carbon linear chain bearing an –SH group at the 4-position.

• Item-specific identifiers (from Product Data):

  • SKU: H985650
  • CAS: 1639-06-1
  • PubChem CID: 12627260
  • Storage Conditions: Room temperature
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.

• Literature/computed identity (general reference; not item-specific):

  • Preferred name: Heptane-4-thiol (4-mercaptoheptane)
  • Molecular formula: C7H16S (literature)
  • Molecular weight: 132.27 g/mol (literature)
  • Example SMILES (literature): CCCC(S)CCC (linear C7 chain with an –SH on C4)

• Structural features (general chemistry description):

  • Functional group: thiol (–SH) on a secondary carbon (C4 of heptane).
  • Saturated aliphatic backbone (no rings, no unsaturation).
  • The –SH at a prochiral center (C4) renders it a secondary thiol; however, the molecule as drawn has no stereocenter because the two sides of C4 are constitutionally different, but the –SH-bearing carbon itself is not stereogenic in the free thiol state unless substituted further.
  • 2D description in words: A straight C7 chain CH3–CH2–CH2–CH(SH)–CH2–CH2–CH3, with the thiol substituent on the central carbon.

Synthetic Utility

Functional group leverage and retrosynthetic value:

• Thiol as a masked/linchpin group: The –SH of heptane-4-thiol enables rapid construction of C–S bonds to form secondary thioethers. Retrosynthetically, sulfides accessible from this thiol can be disconnected to primary electrophiles (halides/OTs/OMs) plus the C7 thiolate.
• Polarity inversion: Thiols allow umpolung-like strategies via thioacetal formation and subsequent manipulations (e.g., Pummerer-type chemistry after sulfoxidation), although such uses are more common with aryl/benzyl sulfides.
• Radical chemistry: In thiol–ene/yne transformations, this thiol serves as a polarity-reversal catalyst or hydrogen-atom donor to drive anti-Markovnikov additions.
• Protecting-group strategies: Conversion to thioesters or disulfides affords more robust intermediates that can be unmasked under mild reductive or hydrolytic conditions.
• Surface immobilization: As an alkanethiol, it provides straightforward anchoring to coinage metals to generate SAMs, facilitating further functionalization at the distal end of an appended molecule.

Practical synthetic notes:

• Generate thiolates with non-nucleophilic bases in dry media to avoid side reactions (e.g., use NaH in THF, then add electrophile).
• Minimize oxidation by excluding air and adding reagents promptly; monitor by GC or NMR for disulfide formation.
• For sensitive targets, use disulfide coupling followed by selective reduction to deliver the free thiol late in the sequence.

Target Specificity

Not applicable. This product is a small-molecule alkanethiol, not a biological targeting reagent or antibody. No antigen/epitope, clone, isotype, or species reactivity information applies.

Frequently Asked Questions

What is the purity of this product?

This product is supplied at ≥95% purity (chemical assay). Lot-specific values are stated on the Certificate of Analysis.

How should this product be stored?

Store at room temperature.

What are the CAS number, molecular formula and molecular weight?

The CAS Number is 1639-06-1, the molecular formula is C7H16S, and the molecular weight is 132.270 g/mol. InChIKey OPLGIZOGDFCNCU-UHFFFAOYSA-N.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.