(alphaS)-alpha-Amino-2,3-dihydro-2-thioxo-1H-imidazole-4-propanoic acid

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  • Identifiers

    CAS number
    2002-22-4

    Molecular formula
    C6H9N3O2S

    SMILES
    C1=C(NC(=S)N1)C[C@@H](C(=O)O)N

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Odorless 83.34%
    Savory 28.52%
    Meaty 25.2%
    Cooked 24.52%
    Roasted 19.13%
    Burnt 17.37%
    Bitter 16.44%
    Sulfurous 14.6%
    Popcorn 14.28%
    Pungent 13.77%

     

    Flavor
    Bitter 70.22%
    Odorless 61.87%
    Mild 30.32%
    Bland 29.46%
    Very mild 22.92%
    Sweet-like 21.28%
    Yeast 21.16%
    Nitrile 20.42%
    Bread crust 19.75%
    Roasted peanuts 19.7%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    -3.6

    pKa est.
    8.1 (weak base)

    Molecular weight
    187.22 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    506°C

    Flash point

    • 241.7 ˚C est.

  • Synonyms

    • 2002-22-4
    • L-Thiolhistidine
    • MH6EDB26P8
    • DTXSID401021728
    • RefChem:405768
    • DTXCID801506704
    • (alphaS)-alpha-Amino-2,3-dihydro-2-thioxo-1H-imidazole-4-propanoic acid
    • 2-Mercapto-L-histidine
    • Thiohistidine
    • (S)-2-Amino-3-(2-thioxo-2,3-dihydro-1H-imidazol-4-yl)propanoic acid
    • H-2-MERCAPTO-HIS-OH
    • (2S)-2-amino-3-(2-sulfanylidene-1,3-dihydroimidazol-4-yl)propanoic acid
    • (2S)-2-amino-3-(2-sulfanyl-1H-imidazol-4-yl)propanoic acid
    • 1H-Imidazole-4-propanoic acid, alpha-amino-2,3-dihydro-2-thioxo-, (alphaS)-
    • (2S)-2-Azaniumyl-3-(2-sulfanylidene-1,3-dihydroimidazol-4-yl)propanoate
    • L-2-Mercaptohistidine
    • UNII-MH6EDB26P8
    • EINECS 217-899-2
    • (S)-2-Mercaptohistidine
    • (S)-alpha-Amino-2,3-dihydro-2-thioxo-1H-imidazole-4-propionic acid
    • L-2-THIOXOHISTIDINE
    • SCHEMBL1065160
    • SCHEMBL1065163
    • SCHEMBL1867162
    • GLXC-25644
    • 2-Mercapto-L-histidine, AldrichCPR
    • (|AS)-|A-Amino-2,3-dihydro-2-thioxo-1H-Imidazole-4-propanoic Acid
    • EBC-64035
    • HISTIDINE, 2-MERCAPTO-, L-
    • 2-THIOLHISTIDINE L-FORM [MI]
    • AKOS006274841
    • AKOS016003297
    • FM25093
    • SY457333
    • CS-0210641
    • NS00046293
    • G84864
    • EN300-7375424
    • 2-​Mercapto-​L-​histidine
    • Q27284033
    • Z1198148773
    • (2S)-2-amino-3-(2-sulfanyl-1H-imidazol-5-yl)propanoic acid
    • (a-S)-a-Amino-2,3-dihydro-2-thioxo-1H-Imidazole-4-propanoic Acid
    • (S)-2-Amino-3-(2-thioxo-2,3-dihydro-1H-imidazol-4-yl)propanoicacid
    • 1H-IMIDAZOLE-4-PROPANOIC ACID, .ALPHA.-AMINO-2,3-DIHYDRO-2-THIOXO-, (.ALPHA.S)-
    • 1H-IMIDAZOLE-4-PROPANOIC ACID, .ALPHA.-AMINO-2,3-DIHYDRO-2-THIOXO-, (S)-
    • 2002-22-4

  • Applications

    The compound (alphaS)-alpha-Amino-2,3-dihydro-2-thioxo-1H-imidazole-4-propanoic acid (CAS 2002-22-4) is widely used in pharmaceutical research as an intermediate and building block for the synthesis of heterocyclic drug candidates. In medicinal chemistry, it serves as a versatile precursor for thiohydantoin- and imidazole-containing compounds and related heterocycles. It also functions as a ligand/reagent in coordination chemistry and catalysis, where its thioxo-imidazole moiety enables metal complex formation. In academic and industrial settings, it is commonly employed as a reference material and starting point for preparing specialized amino acid derivatives and related heterocyclic systems. Subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 0.28
    methanol 1.43
    isopropanol 0.28
    water 64.26
    ethyl acetate 0.48
    n-propanol 0.3
    acetone 1.01
    n-butanol 0.27
    acetonitrile 0.32
    DMF 141.75
    toluene 0.18
    isobutanol 0.26
    1,4-dioxane 1.49
    methyl acetate 0.51
    THF 2.38
    2-butanone 0.62
    n-pentanol 0.21
    sec-butanol 0.26
    n-hexane 0.03
    ethylene glycol 9.78
    NMP 76.26
    cyclohexane 0.06
    DMSO 36.58
    n-butyl acetate 0.4
    n-octanol 0.11
    chloroform 0.08
    n-propyl acetate 0.32
    acetic acid 9.39
    dichloromethane 0.08
    cyclohexanone 1.99
    propylene glycol 5.02
    isopropyl acetate 0.37
    DMAc 72.52
    2-ethoxyethanol 4.56
    isopentanol 0.33
    n-heptane 0.06
    ethyl formate 1.3
    1,2-dichloroethane 0.11
    n-hexanol 0.34
    2-methoxyethanol 12.16
    isobutyl acetate 0.18
    tetrachloromethane 0.09
    n-pentyl acetate 0.27
    transcutol 3.1
    n-heptanol 0.31
    ethylbenzene 0.1
    MIBK 0.49
    2-propoxyethanol 3.91
    tert-butanol 0.69
    MTBE 0.21
    2-butoxyethanol 2.36
    propionic acid 1.94
    o-xylene 0.26
    formic acid 71.26
    diethyl ether 0.19
    m-xylene 0.2
    p-xylene 0.18
    chlorobenzene 0.08
    dimethyl carbonate 2.78
    n-octane 0.03
    formamide 46.89
    cyclopentanone 3.78
    2-pentanone 0.65
    anisole 0.31
    cyclopentyl methyl ether 0.93
    gamma-butyrolactone 6.38
    1-methoxy-2-propanol 5.94
    pyridine 1.12
    3-pentanone 0.68
    furfural 12.23
    n-dodecane 0.01
    diethylene glycol 13.54
    diisopropyl ether 0.09
    tert-amyl alcohol 0.55
    acetylacetone 2.05
    n-hexadecane 0.01
    acetophenone 0.84
    methyl propionate 1.16
    isopentyl acetate 0.41
    trichloroethylene 0.25
    n-nonanol 0.13
    cyclohexanol 0.58
    benzyl alcohol 0.72
    2-ethylhexanol 0.25
    isooctanol 0.26
    dipropyl ether 0.36
    1,2-dichlorobenzene 0.12
    ethyl lactate 1.97
    propylene carbonate 3.37
    n-methylformamide 19.78
    2-pentanol 0.22
    n-pentane 0.03
    1-propoxy-2-propanol 2.12
    1-methoxy-2-propyl acetate 1.47
    2-(2-methoxypropoxy) propanol 3.01
    mesitylene 0.16
    ε-caprolactone 2.2
    p-cymene 0.16
    epichlorohydrin 1.24
    1,1,1-trichloroethane 0.09
    2-aminoethanol 5.94
    morpholine-4-carbaldehyde 39.26
    sulfolane 20.89
    2,2,4-trimethylpentane 0.02
    2-methyltetrahydrofuran 0.77
    n-hexyl acetate 0.21
    isooctane 0.01
    2-(2-butoxyethoxy)ethanol 2.86
    sec-butyl acetate 0.22
    tert-butyl acetate 0.54
    decalin 0.02
    glycerin 35.25
    diglyme 5.51
    acrylic acid 5.03
    isopropyl myristate 0.13
    n-butyric acid 1.64
    acetyl acetate 0.6
    di(2-ethylhexyl) phthalate 0.55
    ethyl propionate 0.41
    nitromethane 13.46
    1,2-diethoxyethane 0.36
    benzonitrile 0.44
    trioctyl phosphate 0.36
    1-bromopropane 0.05
    gamma-valerolactone 13.48
    n-decanol 0.12
    triethyl phosphate 0.72
    4-methyl-2-pentanol 0.2
    propionitrile 0.25
    vinylene carbonate 3.04
    1,1,2-trichlorotrifluoroethane 10.22
    DMS 0.66
    cumene 0.09
    2-octanol 0.15
    2-hexanone 0.3
    octyl acetate 0.2
    limonene 0.2
    1,2-dimethoxyethane 4.86
    ethyl orthosilicate 0.58
    tributyl phosphate 0.35
    diacetone alcohol 2.81
    N,N-dimethylaniline 0.53
    acrylonitrile 0.7
    aniline 0.5
    1,3-propanediol 4.1
    bromobenzene 0.05
    dibromomethane 0.05
    1,1,2,2-tetrachloroethane 0.3
    2-methyl-cyclohexyl acetate 0.53
    tetrabutyl urea 0.87
    diisobutyl methanol 0.21
    2-phenylethanol 0.71
    styrene 0.09
    dioctyl adipate 0.34
    dimethyl sulfate 10.84
    ethyl butyrate 0.52
    methyl lactate 6.96
    butyl lactate 1.22
    diethyl carbonate 0.46
    propanediol butyl ether 2.58
    triethyl orthoformate 0.7
    p-tert-butyltoluene 0.15
    methyl 4-tert-butylbenzoate 1.68
    morpholine 2.36
    tert-butylamine 0.21
    n-dodecanol 0.1
    dimethoxymethane 7.78
    ethylene carbonate 1.8
    cyrene 9.95
    2-ethoxyethyl acetate 0.59
    2-ethylhexyl acetate 0.3
    1,2,4-trichlorobenzene 0.19
    4-methylpyridine 0.92
    dibutyl ether 0.1
    2,6-dimethyl-4-heptanol 0.21
    DEF 4.06
    dimethyl isosorbide 5.5
    tetrachloroethylene 0.34
    eugenol 2.79
    triacetin 1.06
    span 80 2.23
    1,4-butanediol 2.31
    1,1-dichloroethane 0.06
    2-methyl-1-pentanol 0.25
    methyl formate 13.62
    2-methyl-1-butanol 0.34
    n-decane 0.02
    butyronitrile 0.23
    3,7-dimethyl-1-octanol 0.13
    1-chlorooctane 0.03
    1-chlorotetradecane 0.02
    n-nonane 0.02
    undecane 0.02
    tert-butylcyclohexane 0.01
    cyclooctane 0.03
    cyclopentanol 0.98
    tetrahydropyran 0.51
    tert-amyl methyl ether 0.3
    2,5,8-trioxanonane 5.33
    1-hexene 0.06
    2-isopropoxyethanol 1.73
    2,2,2-trifluoroethanol 10.91
    methyl butyrate 0.75

    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