3-Hydroxy-2-oxobutanoic acid

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  • Identifiers

    CAS number
    1944-42-9

    Molecular formula
    C4H6O4

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

    Safety labels

  • Odor profile

    Fragrance
    Caramellic 62.26%
    Buttery 50.14%
    Sweet 41.37%
    Burnt 40.11%
    Sour 38.65%
    Creamy 36.92%
    Odorless 35.32%
    Milky 33.0%
    Fatty 31.5%
    Sharp 30.56%

     

    Flavor
    Odorless 52.31%
    Sour 38.31%
    Very mild 36.92%
    Caramellic 29.98%
    Fruity 25.88%
    Buttery 24.53%
    Creamy 24.06%
    Acidic 22.91%
    Mild 21.39%
    Nutty 21.13%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    -0.6

    pKa est.
    5.98 (weak acid)

    Molecular weight
    118.09 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Very slow

    Boiling point est.
    252°C

    Flash point

    • 120.5 ˚C est.

  • Synonyms

    • 3-hydroxy-2-oxobutanoic acid
    • 1944-42-9
    • Butanoic acid, 3-hydroxy-2-oxo-
    • beta-Hydroxy-alpha-oxobutyric acid
    • beta-Hydroxy-alpha-ketobutyric acid
    • BRQ9FX4AE5
    • DTXSID90941175
    • RefChem:911358
    • DTXCID001369619
    • xi-3-Hydroxy-2-oxobutanoic acid
    • Butanoic acid,3-hydroxy-2-oxo-
    • 3-Hydroxy-alpha-ketobutyrate
    • Butanoic acid, 3-hydroxy-2-oxo- (9CI)
    • 3-hydroxy-2-oxobutanoicacid
    • SCHEMBL1644613
    • Butyric acid, 3-hydroxy-2-oxo-
    • CHEBI:173438
    • alpha-Oxo-beta-hydroxybutyric acid
    • alpha-keto-beta-Hydroxybutyric acid
    • LMFA01050528
    • Butyric acid, beta-hydroxy-alpha-oxo-
    • DB-275188
    • 1944-42-9

  • Applications

    3-Hydroxy-2-oxobutanoic acid (CAS 1944-42-9) is primarily used as a chemical synthesis intermediate, enabling formation of beta-hydroxy ketone motifs and chiral building blocks for pharmaceutical and fine chemicals; it serves as a scaffold for enantioselective routes to access enantioenriched compounds used in drug discovery; in biochemical and enzymology research, it acts as a substrate or assay reagent in studies of threonine/pyruvate metabolism and related enzymes; it may be used as an analytical reference material for methods targeting alpha-keto-beta-hydroxy acids and their derivatives; and in R&D contexts, it can serve as a starting point for preparing functionalized derivatives and small-molecule catalysts or specialty materials.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 88.87
    methanol 259.16
    isopropanol 35.08
    water 143.63
    ethyl acetate 15.15
    n-propanol 39.89
    acetone 42.77
    n-butanol 31.7
    acetonitrile 11.15
    DMF 429.75
    toluene 1.14
    isobutanol 20.98
    1,4-dioxane 27.16
    methyl acetate 13.1
    THF 56.83
    2-butanone 18.9
    n-pentanol 19.18
    sec-butanol 21.28
    n-hexane 0.63
    ethylene glycol 234.33
    NMP 350.21
    cyclohexane 0.45
    DMSO 870.15
    n-butyl acetate 7.8
    n-octanol 13.98
    chloroform 1.05
    n-propyl acetate 7.54
    acetic acid 118.42
    dichloromethane 2.95
    cyclohexanone 26.88
    propylene glycol 117.42
    isopropyl acetate 10.77
    DMAc 194.49
    2-ethoxyethanol 131.22
    isopentanol 29.31
    n-heptane 1.39
    ethyl formate 23.04
    1,2-dichloroethane 6.15
    n-hexanol 20.12
    2-methoxyethanol 319.33
    isobutyl acetate 2.8
    tetrachloromethane 0.58
    n-pentyl acetate 9.02
    transcutol 190.08
    n-heptanol 15.31
    ethylbenzene 1.06
    MIBK 22.34
    2-propoxyethanol 89.5
    tert-butanol 52.59
    MTBE 8.32
    2-butoxyethanol 48.02
    propionic acid 49.39
    o-xylene 2.56
    formic acid 377.73
    diethyl ether 7.94
    m-xylene 2.53
    p-xylene 1.05
    chlorobenzene 1.25
    dimethyl carbonate 19.11
    n-octane 0.65
    formamide 372.08
    cyclopentanone 45.1
    2-pentanone 30.26
    anisole 5.7
    cyclopentyl methyl ether 19.76
    gamma-butyrolactone 89.1
    1-methoxy-2-propanol 191.17
    pyridine 7.57
    3-pentanone 12.63
    furfural 84.25
    n-dodecane 0.56
    diethylene glycol 169.16
    diisopropyl ether 3.83
    tert-amyl alcohol 35.06
    acetylacetone 46.53
    n-hexadecane 0.58
    acetophenone 11.85
    methyl propionate 24.19
    isopentyl acetate 6.86
    trichloroethylene 5.82
    n-nonanol 12.63
    cyclohexanol 17.93
    benzyl alcohol 13.38
    2-ethylhexanol 9.08
    isooctanol 11.13
    dipropyl ether 7.66
    1,2-dichlorobenzene 2.31
    ethyl lactate 23.81
    propylene carbonate 30.63
    n-methylformamide 214.72
    2-pentanol 21.64
    n-pentane 0.89
    1-propoxy-2-propanol 53.02
    1-methoxy-2-propyl acetate 24.32
    2-(2-methoxypropoxy) propanol 51.53
    mesitylene 2.66
    ε-caprolactone 33.81
    p-cymene 2.57
    epichlorohydrin 50.34
    1,1,1-trichloroethane 1.5
    2-aminoethanol 190.55
    morpholine-4-carbaldehyde 214.31
    sulfolane 255.76
    2,2,4-trimethylpentane 0.83
    2-methyltetrahydrofuran 24.84
    n-hexyl acetate 13.78
    isooctane 0.86
    2-(2-butoxyethoxy)ethanol 82.61
    sec-butyl acetate 4.79
    tert-butyl acetate 18.5
    decalin 0.58
    glycerin 265.29
    diglyme 111.14
    acrylic acid 71.72
    isopropyl myristate 5.92
    n-butyric acid 46.9
    acetyl acetate 8.83
    di(2-ethylhexyl) phthalate 10.45
    ethyl propionate 9.68
    nitromethane 167.45
    1,2-diethoxyethane 16.27
    benzonitrile 5.38
    trioctyl phosphate 9.7
    1-bromopropane 2.05
    gamma-valerolactone 129.47
    n-decanol 9.68
    triethyl phosphate 6.85
    4-methyl-2-pentanol 16.45
    propionitrile 6.58
    vinylene carbonate 21.94
    1,1,2-trichlorotrifluoroethane 79.51
    DMS 12.17
    cumene 1.51
    2-octanol 8.93
    2-hexanone 10.44
    octyl acetate 8.93
    limonene 4.5
    1,2-dimethoxyethane 76.63
    ethyl orthosilicate 5.83
    tributyl phosphate 8.8
    diacetone alcohol 83.28
    N,N-dimethylaniline 8.63
    acrylonitrile 15.06
    aniline 6.07
    1,3-propanediol 167.56
    bromobenzene 0.73
    dibromomethane 1.74
    1,1,2,2-tetrachloroethane 6.18
    2-methyl-cyclohexyl acetate 7.63
    tetrabutyl urea 17.9
    diisobutyl methanol 8.2
    2-phenylethanol 12.74
    styrene 1.04
    dioctyl adipate 11.47
    dimethyl sulfate 69.75
    ethyl butyrate 7.84
    methyl lactate 68.5
    butyl lactate 18.55
    diethyl carbonate 4.38
    propanediol butyl ether 61.99
    triethyl orthoformate 6.29
    p-tert-butyltoluene 2.98
    methyl 4-tert-butylbenzoate 28.01
    morpholine 49.09
    tert-butylamine 15.59
    n-dodecanol 7.08
    dimethoxymethane 104.74
    ethylene carbonate 15.05
    cyrene 72.34
    2-ethoxyethyl acetate 17.5
    2-ethylhexyl acetate 4.42
    1,2,4-trichlorobenzene 3.16
    4-methylpyridine 8.33
    dibutyl ether 5.44
    2,6-dimethyl-4-heptanol 8.2
    DEF 63.4
    dimethyl isosorbide 74.52
    tetrachloroethylene 5.39
    eugenol 31.39
    triacetin 22.34
    span 80 46.09
    1,4-butanediol 73.3
    1,1-dichloroethane 1.75
    2-methyl-1-pentanol 16.56
    methyl formate 121.07
    2-methyl-1-butanol 22.53
    n-decane 0.81
    butyronitrile 7.05
    3,7-dimethyl-1-octanol 11.11
    1-chlorooctane 2.92
    1-chlorotetradecane 1.49
    n-nonane 0.77
    undecane 0.66
    tert-butylcyclohexane 0.63
    cyclooctane 0.43
    cyclopentanol 27.18
    tetrahydropyran 8.13
    tert-amyl methyl ether 11.6
    2,5,8-trioxanonane 96.64
    1-hexene 1.49
    2-isopropoxyethanol 56.21
    2,2,2-trifluoroethanol 64.31
    methyl butyrate 14.61

    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