1-Pentanethiol

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  • Identifiers

    CAS number
    110-66-7

    Molecular formula
    C5H12S

    SMILES
    CCCCCS

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Sulfurous 88.07%
    Meaty 78.55%
    Vegetable 67.55%
    Onion 63.09%
    Savory 61.69%
    Roasted 61.11%
    Fatty 61.04%
    Alliaceous 57.05%
    Garlic 54.81%
    Green 45.26%

     

    Flavor
    Sulfurous 63.18%
    Onion 59.44%
    Meaty 52.73%
    Sulfury 51.14%
    Garlic 49.27%
    Fishy 44.22%
    Burnt 43.97%
    Fatty 43.96%
    Roasted 38.1%
    Gassy 36.91%

     

    Odor impact est.
    High

    Odor threshold

    • Odor Threshold Low: 0.0008 [mmHg]. Odor threshold from HSDB
    • The odor threshold of n-pentyl mercaptan has been reported as 0.8 ppb or 0.5 to 0.4 ug/cu m.
    • Odor threshold concentration: 0.0004 mg/cu m

  • Properties

    XLogP3-AA
    2.3

    pKa est.
    10.1 (weak base)

    Molecular weight
    104.22 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Melting point expt.

    • -105 °F (USCG, 1999)
    • -75.69 °C
    • Liquid molar volume = 0.124405 cu m/kmol. Heat of formation = -1.0979X10+8 J/kmol. Heat of fusion = 1.7531X10+7 J/kmol at melting point.
    • -75.7 °C
    • -104 °F

    Boiling point

    • 248 °F at 760 mmHg (USCG, 1999)
    • 126.6 °C
    • BP: 123-124 °C
    • at 61.3kPa: 126.6 °C
    • 260 °F

    Flash point

    • 21.2 ˚C est.
    • 65 °F (USCG, 1999)
    • 18 °C
    • 18 °C (64 °F) - closed cup
    • 65 °F (18 °C) (Open cup)
    • (oc) 65 °F

    Solubility expt.

    • Insoluble (NIOSH, 2024)
    • In water, 156 mg/L at 20 °C
    • In water, 156 mg/L at 25 °C
    • Insoluble in water
    • Miscible with ethanol, ether
    • 0.156 mg/mL at 20 °C
    • Solubility in water: none
    • Sparingly soluble in water
    • Soluble (in ethanol)
    • Insoluble

  • Synonyms

    • 1-Pentanethiol
    • 110-66-7
    • Pentane-1-thiol
    • n-Amyl mercaptan
    • Pentyl mercaptan
    • AMYL MERCAPTAN
    • Pentanethiol
    • Amyl sulfhydrate
    • Amyl thioalcohol
    • Amyl hydrosulfide
    • Pentalarm
    • n-Thioamyl alcohol
    • Pentylmercaptan
    • Thioamyl alcohol
    • 1-Pentanthiol
    • n-Pentylmercaptan
    • 1-Mercaptopentane
    • Mercaptan amylique
    • n-Pentyl mercaptan
    • 1-pentylthiol
    • Caswell No. 642A
    • Mercaptan amilique
    • HSDB 468
    • EINECS 203-789-1
    • EPA Pesticide Chemical Code 100701
    • UNII-9A3YK965F3
    • BRN 1730979
    • PENTANETHIOL, 1-
    • UN 1111 (Salt/Mix)
    • AMYL MERCAPTAN [HSDB]
    • CH3(CH2)4SH
    • 1-PENTANETHIOL [FHFI]
    • N-AMYL MERCAPTAN [MI]
    • DTXSID9041605
    • 9A3YK965F3
    • 4-01-00-01653 (Beilstein Handbook Reference)
    • 1-Pentanethiol, 98%
    • Amyl mercaptans
    • pentylthiol
    • Mercaptopentane
    • n-pentanethiol
    • n-Pentylthiol
    • n-Amylthiol
    • PENTANETHIOLS (AMYL PERCAPTAN)
    • PENTANETHIOLS {AMYL PERCAPTAN}
    • 1-n-Pentanethiol
    • Mercaptan amilique [French]
    • Mercaptan amylique [French]
    • 1-Pentyl mercaptan
    • thiopentane
    • 1pentanethiol
    • nAmyl mercaptan
    • nPentylmercaptan
    • nThioamyl alcohol
    • 1-pentane thiol
    • 1-pentane-thiol
    • 2Methyl1butanethiol
    • MFCD00004907
    • UN1111
    • 2Methylbutyl mercaptan
    • SCHEMBL37855
    • DTXCID7021605
    • CHEBI:173322
    • AKOS015897629
    • USEPA/OPP Pesticide Code: 100701
    • LS-13099
    • DB-021330
    • NS00021516
    • P0053
    • EN300-125882
    • A802231
    • Q3824464

  • Applications

    1-Pentanethiol (CAS 110-66-7) is primarily used as an organic synthesis intermediate to form thioethers and disulfides, and as a thiol source in radical polymerization chain-transfer processes. In fragrance and flavor chemistry, it may be used as an odorant component or as a precursor to sulfur-containing mercaptan compounds used in perfumery and flavor formulations. In surface chemistry and electronics, the thiol group enables binding to metal surfaces (e.g., gold) to form self-assembled monolayers, supporting sensor applications and surface modification. In polymer and coatings technology, it can function as a chain-transfer agent or crosslinking modifier to influence molecular weight and network structure. It may also be considered as an odorant component for gas leak detection or used in adhesive formulations via thiol-ene chemistry. Subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 443.46
    methanol 324.45
    isopropanol 471.02
    water 0.11
    ethyl acetate 349.74
    n-propanol 463.36
    acetone 617.06
    n-butanol 563.79
    acetonitrile 267.21
    DMF 351.57
    toluene 230.17
    isobutanol 353.11
    1,4-dioxane 705.77
    methyl acetate 277.71
    THF 1399.17
    2-butanone 485.64
    n-pentanol 351.38
    sec-butanol 450.09
    n-hexane 260.06
    ethylene glycol 61.04
    NMP 370.52
    cyclohexane 330.95
    DMSO 660.66
    n-butyl acetate 751.85
    n-octanol 249.04
    chloroform 752.96
    n-propyl acetate 300.19
    acetic acid 253.79
    dichloromethane 591.77
    cyclohexanone 801.3
    propylene glycol 114.66
    isopropyl acetate 244.28
    DMAc 211.05
    2-ethoxyethanol 273.01
    isopentanol 441.99
    n-heptane 400.63
    ethyl formate 186.15
    1,2-dichloroethane 386.15
    n-hexanol 757.22
    2-methoxyethanol 468.39
    isobutyl acetate 221.65
    tetrachloromethane 252.66
    n-pentyl acetate 279.57
    transcutol 879.96
    n-heptanol 286.35
    ethylbenzene 123.32
    MIBK 287.45
    2-propoxyethanol 629.4
    tert-butanol 606.4
    MTBE 530.65
    2-butoxyethanol 326.09
    propionic acid 237.77
    o-xylene 131.05
    formic acid 35.1
    diethyl ether 616.77
    m-xylene 149.26
    p-xylene 156.53
    chlorobenzene 267.62
    dimethyl carbonate 63.75
    n-octane 98.32
    formamide 44.01
    cyclopentanone 802.25
    2-pentanone 490.09
    anisole 186.94
    cyclopentyl methyl ether 575.82
    gamma-butyrolactone 548.21
    1-methoxy-2-propanol 397.06
    pyridine 494.63
    3-pentanone 294.91
    furfural 405.35
    n-dodecane 52.43
    diethylene glycol 302.66
    diisopropyl ether 196.43
    tert-amyl alcohol 419.15
    acetylacetone 355.67
    n-hexadecane 58.18
    acetophenone 165.28
    methyl propionate 219.48
    isopentyl acetate 541.1
    trichloroethylene 565.61
    n-nonanol 208.32
    cyclohexanol 477.62
    benzyl alcohol 159.02
    2-ethylhexanol 491.64
    isooctanol 222.97
    dipropyl ether 737.65
    1,2-dichlorobenzene 206.84
    ethyl lactate 100.19
    propylene carbonate 303.18
    n-methylformamide 141.33
    2-pentanol 400.62
    n-pentane 237.36
    1-propoxy-2-propanol 636.51
    1-methoxy-2-propyl acetate 340.52
    2-(2-methoxypropoxy) propanol 226.14
    mesitylene 105.91
    ε-caprolactone 492.07
    p-cymene 157.9
    epichlorohydrin 506.59
    1,1,1-trichloroethane 485.05
    2-aminoethanol 138.96
    morpholine-4-carbaldehyde 389.29
    sulfolane 625.95
    2,2,4-trimethylpentane 77.38
    2-methyltetrahydrofuran 968.18
    n-hexyl acetate 334.03
    isooctane 72.37
    2-(2-butoxyethoxy)ethanol 354.3
    sec-butyl acetate 190.64
    tert-butyl acetate 275.28
    decalin 93.48
    glycerin 134.49
    diglyme 606.63
    acrylic acid 159.78
    isopropyl myristate 149.27
    n-butyric acid 457.95
    acetyl acetate 184.05
    di(2-ethylhexyl) phthalate 110.03
    ethyl propionate 199.32
    nitromethane 266.98
    1,2-diethoxyethane 524.17
    benzonitrile 247.98
    trioctyl phosphate 104.43
    1-bromopropane 536.1
    gamma-valerolactone 620.59
    n-decanol 155.02
    triethyl phosphate 130.81
    4-methyl-2-pentanol 212.71
    propionitrile 316.58
    vinylene carbonate 226.18
    1,1,2-trichlorotrifluoroethane 319.8
    DMS 144.51
    cumene 93.0
    2-octanol 195.84
    2-hexanone 402.52
    octyl acetate 172.15
    limonene 310.1
    1,2-dimethoxyethane 575.93
    ethyl orthosilicate 141.55
    tributyl phosphate 124.31
    diacetone alcohol 300.48
    N,N-dimethylaniline 132.59
    acrylonitrile 259.57
    aniline 230.24
    1,3-propanediol 248.75
    bromobenzene 294.92
    dibromomethane 578.11
    1,1,2,2-tetrachloroethane 502.85
    2-methyl-cyclohexyl acetate 244.94
    tetrabutyl urea 158.2
    diisobutyl methanol 259.64
    2-phenylethanol 248.74
    styrene 162.5
    dioctyl adipate 169.87
    dimethyl sulfate 102.58
    ethyl butyrate 417.81
    methyl lactate 97.69
    butyl lactate 182.32
    diethyl carbonate 194.33
    propanediol butyl ether 253.96
    triethyl orthoformate 266.08
    p-tert-butyltoluene 152.69
    methyl 4-tert-butylbenzoate 173.3
    morpholine 807.41
    tert-butylamine 445.87
    n-dodecanol 125.04
    dimethoxymethane 298.44
    ethylene carbonate 208.52
    cyrene 170.83
    2-ethoxyethyl acetate 256.27
    2-ethylhexyl acetate 452.91
    1,2,4-trichlorobenzene 237.22
    4-methylpyridine 438.83
    dibutyl ether 430.09
    2,6-dimethyl-4-heptanol 259.64
    DEF 328.0
    dimethyl isosorbide 361.87
    tetrachloroethylene 375.84
    eugenol 176.32
    triacetin 201.2
    span 80 273.04
    1,4-butanediol 98.55
    1,1-dichloroethane 503.51
    2-methyl-1-pentanol 286.78
    methyl formate 105.68
    2-methyl-1-butanol 379.99
    n-decane 93.5
    butyronitrile 468.09
    3,7-dimethyl-1-octanol 251.08
    1-chlorooctane 214.9
    1-chlorotetradecane 86.85
    n-nonane 110.11
    undecane 66.73
    tert-butylcyclohexane 93.27
    cyclooctane 117.43
    cyclopentanol 490.65
    tetrahydropyran 1148.68
    tert-amyl methyl ether 333.29
    2,5,8-trioxanonane 391.91
    1-hexene 545.49
    2-isopropoxyethanol 230.26
    2,2,2-trifluoroethanol 54.85
    methyl butyrate 281.64

    Scent© AI

1 4

IFRA standard 51

Recommendation
No restriction
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 No restriction Category 7A
Rinse-off products applied to the hair with some hand contact
 No restriction
Category 2
Products applied to the axillae
 No restriction Category 7B
Leave-on products applied to the hair with some hand contact
 No restriction
Category 3
Products applied to the face/body using fingertips
 No restriction Category 8
Products with significant anogenital exposure
 No restriction
Category 4
Products related to fine fragrance
 No restriction Category 9
Products with body and hand exposure, primarily rinse off
 No restriction
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 No restriction Category 10A
Household care products with mostly hand contact
 No restriction
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 No restriction Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 No restriction
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 No restriction Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 No restriction
Category 5D
Baby Creams, baby Oils and baby talc
 No restriction Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 No restriction
Category 6
Products with oral and lip exposure
 No restriction Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 No restriction