3-(Acetylthio)-2-methylpropanoic acid

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  • Identifiers

    CAS number
    33325-40-5

    Molecular formula
    C6H10O3S

    SMILES
    CC(CSC(=O)C)C(=O)O

    Safety labels

    Corrosive
    Corrosive

  • Odor profile

    Fragrance
    Sulfurous 88.53%
    Tropical 68.9%
    Fruity 63.84%
    Meaty 60.46%
    Cheesy 59.02%
    Roasted 48.7%
    Onion 42.32%
    Savory 42.3%
    Vegetable 41.29%
    Alliaceous 34.78%

     

    Flavor
    Sulfury 34.68%
    Cooked 32.95%
    Odorless 32.63%
    Sulfurous 31.22%
    Cheese 28.79%
    Roasted 28.65%
    Onion 28.65%
    Cabbage 28.6%
    Acidic 25.12%
    Sour 23.58%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    0.7

    pKa est.
    7.78 (neutral)

    Molecular weight
    162.21 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    281°C

    Flash point

    • 127.9 ˚C est.

  • Synonyms

    • 33325-40-5
    • 3-(Acetylthio)-2-methylpropanoic acid
    • Propanoic acid, 3-(acetylthio)-2-methyl-
    • 3-Acetylthioisobutyric acid
    • R696CMV409
    • DTXSID90868398
    • DAT-IBA
    • RefChem:496607
    • DTXCID50816512
    • 277-856-9
    • 3-acetylthio-2-methylpropanoic acid
    • 3-acetylsulfanyl-2-methylpropanoic acid
    • 3-acetylthio-2-methylpropionic acid
    • Captopril EP Impurity G
    • 3-(Acetylthio)-2-methylpropionic acid
    • 3-(Acetylsulfanyl)-2-methylpropanoic acid
    • 3-Acetylthio-2-methylpropionicacid
    • 3-acetylsulfanyl-2-methylpropionic acid
    • (RS)-3-ACETYLTHIO-2-METHYLPROPIONIC ACID
    • 3-MERCAPTO-2-METHYLPROPIONIC ACID ACETATE
    • UNII-R696CMV409
    • EINECS 251-458-5
    • EINECS 277-856-9
    • 2-Methyl-3-(acetylthio)propionic acid
    • 3-acetylsulfanyl-2-methyl-propanoic acid
    • 3-Mercapto-2-methylpropionic acid, acetate
    • SCHEMBL342981
    • VFVHNRJEYQGRGE-UHFFFAOYSA-
    • HMS1661N04
    • EINECS 278-480-8
    • CCG-40872
    • MFCD00066543
    • s-acetyl-beta-mercaptoisobutyric acid
    • AKOS006228965
    • FA17189
    • 2-methyl-3-acetylmercaptopropionic acid
    • (r,s)-beta-acetylmercaptoisobutyric acid
    • (S)-beta-(Acetylmercapto)isobutyric acid
    • 2-(ACETYLTHIOMETHYL)PROPANOIC ACID
    • 3-acetylthio 2-(RS) methylpropionic acid
    • 3-acetylthio-2-(RS) methylpropionic acid
    • CAPTOPRIL IMPURITY G [EP IMPURITY]
    • (S)-3-(Acetylthio)-2-methylpropionic acid
    • D-3-Acetylsulfanyl-2-methyl propionic acid
    • D-3-Acetylsulfanyl-2-methyl-propionic acid
    • DB-056070
    • S-Acetyl-2-methyl-3-mercaptopropionic acid
    • (1)-3-(Acetylthio)-2-methylpropionic acid
    • 3-(Acetylsulfanyl)-2-methylpropanoic acid #
    • NS00054582
    • H51475
    • (+/-)-3-ACETYLTHIO-2-METHYLPROPIONIC ACID
    • SR-01000630983-1
    • PROPIONIC ACID, 3-MERCAPTO-2-METHYL-, ACETATE
    • Q27287849
    • 3-Mercapto-2-methylpropionic Acid Acetate (RS)-3-Acetylthio-2-methylpropionic Acid
    • InChI=1/C6H10O3S/c1-4(6(8)9)3-10-5(2)7/h4H,3H2,1-2H3,(H,8,9)
    • 33325-40-5

  • Applications

    3-(Acetylthio)-2-methylpropanoic acid (CAS 33325-40-5) is primarily an organic synthesis intermediate. It functions as a protected thiol-building block and as a thioester precursor for acylation steps, enabling introduction of sulfur-containing motifs in pharmaceutical and fine-chemical syntheses. It also finds use in peptide chemistry and peptidomimetics, where thiol-protected intermediates and thioester linkages are valuable for constructing sulfur-containing backbones. In polymer and materials science, the thioester functionality provides a handle for post-polymerization modification or for incorporating sulfur-containing motifs into monomers or crosslinkers. Its use is subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 161.2
    methanol 245.24
    isopropanol 126.84
    water 104.8
    ethyl acetate 39.54
    n-propanol 104.3
    acetone 134.61
    n-butanol 89.4
    acetonitrile 55.56
    DMF 505.39
    toluene 10.98
    isobutanol 73.64
    1,4-dioxane 212.7
    methyl acetate 57.0
    THF 203.65
    2-butanone 70.21
    n-pentanol 65.54
    sec-butanol 87.55
    n-hexane 3.11
    ethylene glycol 106.55
    NMP 473.95
    cyclohexane 3.98
    DMSO 346.01
    n-butyl acetate 27.83
    n-octanol 51.8
    chloroform 32.14
    n-propyl acetate 29.42
    acetic acid 156.03
    dichloromethane 48.85
    cyclohexanone 136.93
    propylene glycol 117.28
    isopropyl acetate 33.46
    DMAc 400.67
    2-ethoxyethanol 150.44
    isopentanol 71.72
    n-heptane 3.46
    ethyl formate 58.78
    1,2-dichloroethane 35.55
    n-hexanol 52.59
    2-methoxyethanol 259.38
    isobutyl acetate 20.94
    tetrachloromethane 6.53
    n-pentyl acetate 36.7
    transcutol 219.29
    n-heptanol 46.8
    ethylbenzene 14.19
    MIBK 46.08
    2-propoxyethanol 118.72
    tert-butanol 141.03
    MTBE 51.47
    2-butoxyethanol 97.17
    propionic acid 98.83
    o-xylene 22.8
    formic acid 167.72
    diethyl ether 30.34
    m-xylene 18.45
    p-xylene 20.53
    chlorobenzene 19.51
    dimethyl carbonate 34.48
    n-octane 2.83
    formamide 214.59
    cyclopentanone 203.26
    2-pentanone 58.93
    anisole 47.34
    cyclopentyl methyl ether 65.01
    gamma-butyrolactone 236.22
    1-methoxy-2-propanol 183.09
    pyridine 59.33
    3-pentanone 37.12
    furfural 218.15
    n-dodecane 2.87
    diethylene glycol 141.08
    diisopropyl ether 13.26
    tert-amyl alcohol 103.34
    acetylacetone 92.02
    n-hexadecane 3.16
    acetophenone 63.16
    methyl propionate 48.88
    isopentyl acetate 33.4
    trichloroethylene 61.15
    n-nonanol 45.46
    cyclohexanol 72.83
    benzyl alcohol 60.83
    2-ethylhexanol 30.86
    isooctanol 38.13
    dipropyl ether 20.03
    1,2-dichlorobenzene 26.87
    ethyl lactate 37.95
    propylene carbonate 109.28
    n-methylformamide 198.15
    2-pentanol 52.64
    n-pentane 3.11
    1-propoxy-2-propanol 74.93
    1-methoxy-2-propyl acetate 52.64
    2-(2-methoxypropoxy) propanol 94.67
    mesitylene 16.13
    ε-caprolactone 124.96
    p-cymene 14.7
    epichlorohydrin 156.89
    1,1,1-trichloroethane 23.66
    2-aminoethanol 149.68
    morpholine-4-carbaldehyde 407.66
    sulfolane 346.73
    2,2,4-trimethylpentane 3.21
    2-methyltetrahydrofuran 112.8
    n-hexyl acetate 56.38
    isooctane 2.61
    2-(2-butoxyethoxy)ethanol 117.62
    sec-butyl acetate 23.09
    tert-butyl acetate 46.81
    decalin 4.21
    glycerin 186.39
    diglyme 176.63
    acrylic acid 104.86
    isopropyl myristate 24.1
    n-butyric acid 86.76
    acetyl acetate 34.43
    di(2-ethylhexyl) phthalate 38.16
    ethyl propionate 28.73
    nitromethane 230.37
    1,2-diethoxyethane 46.02
    benzonitrile 50.32
    trioctyl phosphate 30.38
    1-bromopropane 13.67
    gamma-valerolactone 316.71
    n-decanol 33.99
    triethyl phosphate 23.3
    4-methyl-2-pentanol 35.8
    propionitrile 36.66
    vinylene carbonate 98.65
    1,1,2-trichlorotrifluoroethane 136.03
    DMS 42.89
    cumene 14.68
    2-octanol 33.04
    2-hexanone 44.2
    octyl acetate 34.93
    limonene 20.58
    1,2-dimethoxyethane 183.02
    ethyl orthosilicate 22.2
    tributyl phosphate 28.85
    diacetone alcohol 103.31
    N,N-dimethylaniline 54.61
    acrylonitrile 56.51
    aniline 35.85
    1,3-propanediol 158.44
    bromobenzene 14.77
    dibromomethane 24.63
    1,1,2,2-tetrachloroethane 55.26
    2-methyl-cyclohexyl acetate 38.81
    tetrabutyl urea 47.75
    diisobutyl methanol 23.41
    2-phenylethanol 51.13
    styrene 13.58
    dioctyl adipate 42.42
    dimethyl sulfate 93.28
    ethyl butyrate 25.59
    methyl lactate 71.21
    butyl lactate 48.09
    diethyl carbonate 18.12
    propanediol butyl ether 110.17
    triethyl orthoformate 23.42
    p-tert-butyltoluene 14.99
    methyl 4-tert-butylbenzoate 80.63
    morpholine 205.57
    tert-butylamine 59.62
    n-dodecanol 24.96
    dimethoxymethane 137.61
    ethylene carbonate 71.7
    cyrene 138.03
    2-ethoxyethyl acetate 55.69
    2-ethylhexyl acetate 24.06
    1,2,4-trichlorobenzene 37.5
    4-methylpyridine 70.58
    dibutyl ether 24.66
    2,6-dimethyl-4-heptanol 23.41
    DEF 111.73
    dimethyl isosorbide 137.89
    tetrachloroethylene 36.17
    eugenol 83.01
    triacetin 69.55
    span 80 88.08
    1,4-butanediol 86.46
    1,1-dichloroethane 25.57
    2-methyl-1-pentanol 58.23
    methyl formate 145.17
    2-methyl-1-butanol 66.85
    n-decane 4.46
    butyronitrile 43.58
    3,7-dimethyl-1-octanol 41.85
    1-chlorooctane 16.84
    1-chlorotetradecane 7.46
    n-nonane 4.07
    undecane 3.5
    tert-butylcyclohexane 4.15
    cyclooctane 2.47
    cyclopentanol 105.54
    tetrahydropyran 76.93
    tert-amyl methyl ether 42.07
    2,5,8-trioxanonane 146.47
    1-hexene 9.95
    2-isopropoxyethanol 93.15
    2,2,2-trifluoroethanol 87.54
    methyl butyrate 45.28

    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