2-Butyl isothiocyanate

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  • Identifiers

    CAS number
    4426-79-3

    Molecular formula
    C5H9NS

    SMILES
    CCC(C)N=C=S

    Safety labels

    Flammable
    Flammable

    Corrosive
    Corrosive

    Acute Toxic
    Acute Toxic

    Irritant
    Irritant

  • Odor profile

    Green 88.1%
    Pungent 82.06%
    Radish 73.97%
    Vegetable 45.97%
    Cabbage 30.52%
    Alliaceous 28.86%
    Tomato 26.4%
    Sulfurous 25.61%
    Sharp 25.24%
    Metallic 23.69%

    Scent© AI

  • Properties

    XLogP3-AA
    2.8

    pKa est.
    8.78 (weak base)

    Molecular weight
    115.2 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Very fast

    Boiling point est.
    174°C

    Flash point est.
    40.06 ˚C

    Solubility expt.

    • Very slightly soluble in water; freely soluble in ether
    • Soluble (in ethanol)

  • Synonyms

    • sec-Butyl isothiocyanate
    • 4426-79-3
    • 2-Isothiocyanatobutane
    • 2-Butyl isothiocyanate
    • Butane, 2-isothiocyanato-
    • Isothiocyanic Acid sec-Butyl Ester
    • 2-Butylisothiocyanate
    • Isothiocyanic acid, sec-butyl ester
    • 1-Methylpropyl isothiocyanate
    • 126JI237AW
    • EINECS 224-609-8
    • CHEMBL3593576
    • FEMA NO. 4419
    • DTXSID80863392
    • 2-BUTYLISOTHIOCYANATE [FHFI]
    • (+/-)-2-BUTYL ISOTHIOCYANATE
    • 2-BUTYL ISOTHIOCYANATE, (+/-)-
    • SEC-BUTYLISOTHIOCYANATE
    • UNII-126JI237AW
    • MFCD00041108
    • s-butyl isothiocyanate
    • 2-Isothiocyanatobutane #
    • SCHEMBL331115
    • DTXCID90812018
    • BBL027965
    • BDBM50096278
    • NSC826749
    • STK397518
    • AKOS000212507
    • AKOS016042567
    • NSC-826749
    • VS-08633
    • DB-023065
    • I0481
    • NS00048698
    • EN300-62130
    • D91163
    • Q27251375
    • Z323038722
    • 224-609-8

  • Applications

    2-Butyl isothiocyanate (CAS 4426-79-3) is a hydrophobic linear isothiocyanate used as a versatile electrophile and synthetic building block to access thioureas, thiocarbamates, and dithiocarbamates via rapid reactions with amines, alcohols, or thiols; it finds use in medicinal and agrochemical discovery to append a flexible butyl group and tune lipophilicity, permeability, and H-bonding; serves as a precursor to S,N-heterocycles (e.g., thiazolines, thiazolidinones) and to thiourea-based ligands/organocatalysts in organic synthesis; in analytical and bioconjugation workflows it acts as a derivatization reagent for amine-bearing peptides, polymers, and amine-functional surfaces to form stable thiourea linkages that aid LC/GC detection, retention control, and labeling; in materials science it reacts with amine-rich polymers/oligomers to build thiourea networks for metal capture, enzyme immobilization, or corrosion resistance; it is also used as a reference/control in isothiocyanate reactivity studies; handle in a fume hood due to its pungent odor and irritancy.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 37.51
    methanol 29.34
    isopropanol 36.95
    water 0.03
    ethyl acetate 79.0
    n-propanol 38.66
    acetone 165.04
    n-butanol 45.41
    acetonitrile 67.15
    DMF 182.7
    toluene 100.07
    isobutanol 37.05
    1,4-dioxane 156.41
    methyl acetate 106.84
    THF 282.39
    2-butanone 145.52
    n-pentanol 43.58
    sec-butanol 44.52
    n-hexane 24.09
    ethylene glycol 11.18
    NMP 244.82
    cyclohexane 36.43
    DMSO 240.47
    n-butyl acetate 123.48
    n-octanol 50.32
    chloroform 355.66
    n-propyl acetate 73.41
    acetic acid 63.29
    dichloromethane 305.94
    cyclohexanone 219.79
    propylene glycol 21.49
    isopropyl acetate 61.27
    DMAc 191.15
    2-ethoxyethanol 56.42
    isopentanol 50.53
    n-heptane 22.23
    ethyl formate 54.79
    1,2-dichloroethane 192.21
    n-hexanol 68.0
    2-methoxyethanol 76.84
    isobutyl acetate 60.17
    tetrachloromethane 61.42
    n-pentyl acetate 81.84
    transcutol 275.37
    n-heptanol 38.25
    ethylbenzene 62.24
    MIBK 75.31
    2-propoxyethanol 96.65
    tert-butanol 62.04
    MTBE 91.98
    2-butoxyethanol 65.31
    propionic acid 52.33
    o-xylene 71.74
    formic acid 9.71
    diethyl ether 65.46
    m-xylene 67.61
    p-xylene 87.84
    chlorobenzene 153.71
    dimethyl carbonate 35.76
    n-octane 11.65
    formamide 16.07
    cyclopentanone 303.5
    2-pentanone 103.51
    anisole 107.98
    cyclopentyl methyl ether 125.49
    gamma-butyrolactone 243.31
    1-methoxy-2-propanol 69.07
    pyridine 196.84
    3-pentanone 96.02
    furfural 242.24
    n-dodecane 11.41
    diethylene glycol 63.46
    diisopropyl ether 32.92
    tert-amyl alcohol 62.09
    acetylacetone 136.28
    n-hexadecane 13.15
    acetophenone 119.76
    methyl propionate 72.0
    isopentyl acetate 113.87
    trichloroethylene 411.54
    n-nonanol 45.16
    cyclohexanol 69.86
    benzyl alcohol 79.11
    2-ethylhexanol 62.88
    isooctanol 34.88
    dipropyl ether 67.18
    1,2-dichlorobenzene 144.76
    ethyl lactate 39.95
    propylene carbonate 135.31
    n-methylformamide 47.15
    2-pentanol 38.3
    n-pentane 16.65
    1-propoxy-2-propanol 87.71
    1-methoxy-2-propyl acetate 105.59
    2-(2-methoxypropoxy) propanol 104.1
    mesitylene 47.49
    ε-caprolactone 158.95
    p-cymene 55.23
    epichlorohydrin 252.85
    1,1,1-trichloroethane 226.67
    2-aminoethanol 21.82
    morpholine-4-carbaldehyde 191.53
    sulfolane 349.84
    2,2,4-trimethylpentane 14.96
    2-methyltetrahydrofuran 197.36
    n-hexyl acetate 115.9
    isooctane 10.88
    2-(2-butoxyethoxy)ethanol 111.73
    sec-butyl acetate 58.37
    tert-butyl acetate 84.81
    decalin 24.18
    glycerin 30.07
    diglyme 202.74
    acrylic acid 53.15
    isopropyl myristate 58.15
    n-butyric acid 71.55
    acetyl acetate 70.15
    di(2-ethylhexyl) phthalate 61.64
    ethyl propionate 61.48
    nitromethane 116.1
    1,2-diethoxyethane 124.07
    benzonitrile 130.86
    trioctyl phosphate 40.89
    1-bromopropane 119.18
    gamma-valerolactone 244.58
    n-decanol 37.01
    triethyl phosphate 53.18
    4-methyl-2-pentanol 31.84
    propionitrile 63.15
    vinylene carbonate 117.79
    1,1,2-trichlorotrifluoroethane 162.85
    DMS 101.46
    cumene 45.18
    2-octanol 33.83
    2-hexanone 103.84
    octyl acetate 67.86
    limonene 76.67
    1,2-dimethoxyethane 139.63
    ethyl orthosilicate 51.76
    tributyl phosphate 51.91
    diacetone alcohol 92.53
    N,N-dimethylaniline 85.21
    acrylonitrile 82.7
    aniline 85.88
    1,3-propanediol 33.08
    bromobenzene 184.8
    dibromomethane 227.54
    1,1,2,2-tetrachloroethane 319.75
    2-methyl-cyclohexyl acetate 93.12
    tetrabutyl urea 68.43
    diisobutyl methanol 43.42
    2-phenylethanol 92.45
    styrene 79.21
    dioctyl adipate 86.22
    dimethyl sulfate 78.14
    ethyl butyrate 84.87
    methyl lactate 41.94
    butyl lactate 65.98
    diethyl carbonate 62.41
    propanediol butyl ether 75.55
    triethyl orthoformate 65.3
    p-tert-butyltoluene 54.16
    methyl 4-tert-butylbenzoate 95.23
    morpholine 147.15
    tert-butylamine 46.36
    n-dodecanol 31.77
    dimethoxymethane 81.24
    ethylene carbonate 84.37
    cyrene 100.23
    2-ethoxyethyl acetate 106.57
    2-ethylhexyl acetate 100.37
    1,2,4-trichlorobenzene 196.15
    4-methylpyridine 201.95
    dibutyl ether 82.14
    2,6-dimethyl-4-heptanol 43.42
    DEF 103.07
    dimethyl isosorbide 172.66
    tetrachloroethylene 186.93
    eugenol 94.75
    triacetin 118.3
    span 80 98.66
    1,4-butanediol 20.32
    1,1-dichloroethane 195.33
    2-methyl-1-pentanol 52.0
    methyl formate 48.56
    2-methyl-1-butanol 46.7
    n-decane 16.56
    butyronitrile 72.34
    3,7-dimethyl-1-octanol 60.69
    1-chlorooctane 57.01
    1-chlorotetradecane 28.17
    n-nonane 16.9
    undecane 13.29
    tert-butylcyclohexane 22.36
    cyclooctane 15.36
    cyclopentanol 80.68
    tetrahydropyran 151.3
    tert-amyl methyl ether 76.33
    2,5,8-trioxanonane 159.77
    1-hexene 61.24
    2-isopropoxyethanol 54.23
    2,2,2-trifluoroethanol 23.29
    methyl butyrate 87.24

    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

Botanical

Name CAS Botanical Proportion
Horseradish Armoracia lapathifolia Gilib., fam. Brassicaceae (Cruciferae) 1.5%