Isobutyl mercaptan

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  • Identifiers

    CAS number
    513-44-0

    Molecular formula
    C4H10S

    SMILES
    CC(C)CS

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Sulfurous 90.27%
    Meaty 71.06%
    Onion 69.82%
    Garlic 62.37%
    Vegetable 60.92%
    Alliaceous 56.31%
    Savory 56.13%
    Roasted 46.15%
    Cheesy 42.17%
    Cooked 41.26%

     

    Flavor
    Sulfurous 55.49%
    Onion 54.01%
    Meaty 42.09%
    Fishy 39.93%
    Sulfury 32.74%
    Vegetable 31.33%
    Garlic 28.21%
    Gassy 26.48%
    Cooked 26.07%
    Roasted 25.36%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    1.8

    pKa est.
    10.85 (weak base)

    Molecular weight
    90.19 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Melting point expt.

    • -79 °C

    Boiling point

    • 88.50 °C. @ 760.00 mm Hg

    Flash point

    • -4.82 ˚C est.

    Solubility expt.

    • soluble in oil and alcohol

  • Synonyms

    • Isobutyl mercaptan
    • 2-METHYL-1-PROPANETHIOL
    • 513-44-0
    • 2-Methylpropane-1-thiol
    • Isobutylmercaptan
    • Isobutanethiol
    • 1-Propanethiol, 2-methyl-
    • Isobutyl thiol
    • 1-Isobutanethiol
    • 2-Methylpropyl mercaptan
    • EINECS 208-162-6
    • BRN 1730890
    • 9H070UFP2X
    • 2-Methyl propanethiol
    • iso-C4H9SH
    • 2-Methyl-1-propylthiol
    • ISOBUTYL MERCAPTAN [MI]
    • DTXSID9060156
    • FEMA NO. 3874
    • BDFAOUQQXJIZDG-UHFFFAOYSA-
    • 4-01-00-01605 (Beilstein Handbook Reference)
    • 2-METHYL-1-PROPANETHIOL [FHFI]
    • UNII-9H070UFP2X
    • iso-butyl thiol
    • 1-Mercaptoisobutane
    • Thioisobutyl alcohol
    • 2-methylpropanethiol
    • MFCD00004882
    • 2-methyl-propanethiol
    • 2-methyl-propane-1-thiol
    • 1-Mercapto-2-methylpropane
    • DTXCID2040999
    • FEMA 3874
    • AKOS000120213
    • 2-Methyl-1-propanethiol, >=95%, FG
    • M0404
    • NS00021184
    • EN300-20684
    • 2-Methyl-1-propanethiol, 92%, technical grade
    • A828544
    • Q27272544
    • F0001-1336
    • 1-Isobutanethiol; 2-Methylpropyl mercaptan; Isobutyl mercaptan; Isobutyl thiol; NSC 203271; 1-?Propanethiol, 2-?methyl-

  • Applications

    2-Methyl-1-propanethiol (isobutyl mercaptan) with its very strong sulfurous odour is employed at trace levels as a flavour ingredient to recreate grapefruit, roasted coffee or aged cheese notes in the food industry, serves as an odorising agent for natural gas leak detection, acts as a protective reagent in organic synthesis for introducing –SH groups or building thioesters, functions as a chain-transfer modifier in sulfur-mediated polymerisations to control polymer length, works as a metal-complexing ligand in extraction and electroplating, forms self-assembled monolayers on gold surfaces for microelectronic sensors, and is used as an intermediate for preparing pharmaceutical derivatives bearing the isobutylthio motif.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 105.91
    methanol 86.81
    isopropanol 96.67
    water 0.28
    ethyl acetate 101.89
    n-propanol 107.33
    acetone 94.79
    n-butanol 125.5
    acetonitrile 62.77
    DMF 67.48
    toluene 60.37
    isobutanol 74.85
    1,4-dioxane 172.33
    methyl acetate 85.26
    THF 315.18
    2-butanone 109.87
    n-pentanol 87.78
    sec-butanol 111.81
    n-hexane 63.96
    ethylene glycol 20.1
    NMP 98.59
    cyclohexane 75.34
    DMSO 88.14
    n-butyl acetate 173.29
    n-octanol 87.55
    chloroform 253.2
    n-propyl acetate 70.86
    acetic acid 77.59
    dichloromethane 155.57
    cyclohexanone 152.43
    propylene glycol 41.84
    isopropyl acetate 73.16
    DMAc 79.54
    2-ethoxyethanol 85.34
    isopentanol 96.93
    n-heptane 104.69
    ethyl formate 48.56
    1,2-dichloroethane 91.57
    n-hexanol 197.95
    2-methoxyethanol 123.0
    isobutyl acetate 52.19
    tetrachloromethane 81.18
    n-pentyl acetate 87.16
    transcutol 318.69
    n-heptanol 98.76
    ethylbenzene 35.26
    MIBK 65.69
    2-propoxyethanol 191.76
    tert-butanol 125.6
    MTBE 118.36
    2-butoxyethanol 123.85
    propionic acid 76.17
    o-xylene 43.65
    formic acid 16.94
    diethyl ether 142.98
    m-xylene 42.57
    p-xylene 44.86
    chlorobenzene 80.09
    dimethyl carbonate 21.93
    n-octane 30.84
    formamide 22.44
    cyclopentanone 171.14
    2-pentanone 107.07
    anisole 63.94
    cyclopentyl methyl ether 140.76
    gamma-butyrolactone 131.23
    1-methoxy-2-propanol 113.88
    pyridine 135.66
    3-pentanone 85.46
    furfural 115.31
    n-dodecane 17.79
    diethylene glycol 106.24
    diisopropyl ether 53.11
    tert-amyl alcohol 129.9
    acetylacetone 89.24
    n-hexadecane 19.11
    acetophenone 56.63
    methyl propionate 66.92
    isopentyl acetate 122.03
    trichloroethylene 171.07
    n-nonanol 82.2
    cyclohexanol 108.48
    benzyl alcohol 54.21
    2-ethylhexanol 143.28
    isooctanol 74.83
    dipropyl ether 174.56
    1,2-dichlorobenzene 62.96
    ethyl lactate 37.4
    propylene carbonate 84.73
    n-methylformamide 35.52
    2-pentanol 98.54
    n-pentane 60.98
    1-propoxy-2-propanol 188.47
    1-methoxy-2-propyl acetate 109.29
    2-(2-methoxypropoxy) propanol 104.59
    mesitylene 30.24
    ε-caprolactone 121.97
    p-cymene 52.82
    epichlorohydrin 129.79
    1,1,1-trichloroethane 131.15
    2-aminoethanol 45.95
    morpholine-4-carbaldehyde 108.38
    sulfolane 133.25
    2,2,4-trimethylpentane 25.41
    2-methyltetrahydrofuran 222.14
    n-hexyl acetate 109.09
    isooctane 17.42
    2-(2-butoxyethoxy)ethanol 147.57
    sec-butyl acetate 55.68
    tert-butyl acetate 87.25
    decalin 28.26
    glycerin 49.01
    diglyme 203.89
    acrylic acid 56.6
    isopropyl myristate 54.25
    n-butyric acid 120.69
    acetyl acetate 66.07
    di(2-ethylhexyl) phthalate 47.01
    ethyl propionate 60.21
    nitromethane 72.42
    1,2-diethoxyethane 157.68
    benzonitrile 66.99
    trioctyl phosphate 39.57
    1-bromopropane 118.61
    gamma-valerolactone 142.67
    n-decanol 63.49
    triethyl phosphate 49.78
    4-methyl-2-pentanol 57.77
    propionitrile 76.92
    vinylene carbonate 64.61
    1,1,2-trichlorotrifluoroethane 111.74
    DMS 53.65
    cumene 29.93
    2-octanol 67.03
    2-hexanone 90.6
    octyl acetate 68.52
    limonene 88.42
    1,2-dimethoxyethane 130.56
    ethyl orthosilicate 54.8
    tributyl phosphate 45.35
    diacetone alcohol 99.12
    N,N-dimethylaniline 47.17
    acrylonitrile 64.25
    aniline 77.07
    1,3-propanediol 72.12
    bromobenzene 77.27
    dibromomethane 143.55
    1,1,2,2-tetrachloroethane 153.37
    2-methyl-cyclohexyl acetate 85.36
    tetrabutyl urea 53.84
    diisobutyl methanol 75.23
    2-phenylethanol 94.93
    styrene 45.05
    dioctyl adipate 65.46
    dimethyl sulfate 30.55
    ethyl butyrate 116.03
    methyl lactate 39.13
    butyl lactate 71.11
    diethyl carbonate 65.22
    propanediol butyl ether 90.24
    triethyl orthoformate 91.68
    p-tert-butyltoluene 53.52
    methyl 4-tert-butylbenzoate 73.05
    morpholine 189.85
    tert-butylamine 99.77
    n-dodecanol 51.3
    dimethoxymethane 65.82
    ethylene carbonate 56.7
    cyrene 66.87
    2-ethoxyethyl acetate 92.44
    2-ethylhexyl acetate 111.77
    1,2,4-trichlorobenzene 81.43
    4-methylpyridine 106.24
    dibutyl ether 122.19
    2,6-dimethyl-4-heptanol 75.23
    DEF 84.79
    dimethyl isosorbide 137.42
    tetrachloroethylene 117.15
    eugenol 73.17
    triacetin 88.67
    span 80 118.94
    1,4-butanediol 30.01
    1,1-dichloroethane 114.48
    2-methyl-1-pentanol 81.17
    methyl formate 25.39
    2-methyl-1-butanol 93.27
    n-decane 32.75
    butyronitrile 98.41
    3,7-dimethyl-1-octanol 86.75
    1-chlorooctane 68.22
    1-chlorotetradecane 29.65
    n-nonane 34.96
    undecane 23.03
    tert-butylcyclohexane 27.8
    cyclooctane 32.63
    cyclopentanol 111.04
    tetrahydropyran 223.85
    tert-amyl methyl ether 98.42
    2,5,8-trioxanonane 148.92
    1-hexene 110.76
    2-isopropoxyethanol 76.91
    2,2,2-trifluoroethanol 26.42
    methyl butyrate 73.4

    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