2-Ketobutyric acid methyl ester

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  • Identifiers

    CAS number
    3952-66-7

    Molecular formula
    C5H8O3

    SMILES
    CCC(=O)C(=O)OC

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

    Health Hazard
    Health

  • Odor profile

    Fragrance
    Fruity 88.14%
    Caramellic 80.98%
    Sweet 63.26%
    Buttery 48.99%
    Ethereal 47.6%
    Burnt 46.54%
    Rummy 44.11%
    Winey 43.42%
    Nutty 41.4%
    Creamy 37.97%

     

    Flavor
    Fruity 64.73%
    Caramel 55.94%
    Creamy 54.77%
    Sweet 49.46%
    Buttery 48.1%
    Butter 45.01%
    Fatty 36.22%
    Oily 33.77%
    Nutty 32.83%
    Cheese 32.71%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    0.5

    pKa est.
    6.88 (neutral)

    Molecular weight
    116.11 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Very fast

    Boiling point est.
    155°C

    Flash point

    • 33.22 ˚C est.

  • Synonyms

    • 2-ketobutyric acid methyl ester
    • RefChem:473942
    • 635-794-3
    • Methyl 2-oxobutanoate
    • 3952-66-7
    • 2-oxoButanoic acid methyl ester
    • METHYL 2-KETOBUTYRATE
    • Methyl 2-oxobutyrate
    • MFCD03093092
    • Butanoic acid, 2-oxo-, methyl ester
    • Methyl2-Oxobutanoate
    • 2-Oxobutyric acid methyl ester
    • Butyric acid, 2-oxo-, methyl ester
    • Methyl 2-ketobutyrate; Methyl 2-oxobutanoate; Methyl 2-oxobutyrate; Methyl alpha-Oxobutyrate; 2-Oxobutyric Acid Methyl Ester; 2-Oxobutanoic Acid Methyl Ester
    • methyl oxo-butanoate
    • Methyl-2-ketobutyrate
    • methyl 2-oxo-butyrate
    • Methyl 2-oxobutanoate #
    • Methyl .alpha.-oxobutyrate
    • 2-OxobutanoicAcidMethylEster
    • Methyl 2-oxobutanoate, 95%
    • SCHEMBL120572
    • SCHEMBL5222247
    • SCHEMBL9501353
    • 2-oxo-butyric acid methyl ester
    • 2-Ketobutyric acid, methyl ester
    • DTXSID50337853
    • Methyl ester of 2-oxobutanoic acid
    • AKOS006227654
    • AS-47831
    • SY005236
    • DB-069829
    • M2369
    • EN300-109087
    • F16310
    • 3952-66-7

  • Applications

    2-Ketobutyric acid methyl ester (CAS 3952-66-7) is primarily used as an organic synthesis intermediate, enabling access to beta-ketoester motifs and related 1,3-dicarbonyl chemistry. It is commonly employed as a building block in pharmaceutical development to prepare amino acid derivatives and other pharmacophores, and in agrochemical synthesis as a precursor to more complex active ingredients. It may serve as a precursor or intermediate in fragrance and cosmetic chemistry, providing routes to odor-active esters and related compounds. In general, it is used in industrial manufacturing and process development as a versatile reagent for chain-extension and carbonyl chemistry in small- to medium-scale syntheses, and it is frequently encountered in research and development settings as a versatile beta-keto ester starting material. Subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 1049.7
    methanol 1795.77
    isopropanol 668.86
    water 75.83
    ethyl acetate 1387.62
    n-propanol 743.29
    acetone 2352.67
    n-butanol 572.49
    acetonitrile 2758.5
    DMF 2857.62
    toluene 288.63
    isobutanol 489.39
    1,4-dioxane 2047.79
    methyl acetate 1847.13
    THF 1498.79
    2-butanone 1531.01
    n-pentanol 544.67
    sec-butanol 622.99
    n-hexane 93.0
    ethylene glycol 657.74
    NMP 2260.68
    cyclohexane 128.86
    DMSO 3111.89
    n-butyl acetate 662.82
    n-octanol 358.92
    chloroform 2601.33
    n-propyl acetate 978.2
    acetic acid 3134.53
    dichloromethane 3009.63
    cyclohexanone 1604.89
    propylene glycol 431.08
    isopropyl acetate 651.11
    DMAc 1648.56
    2-ethoxyethanol 1448.36
    isopentanol 416.51
    n-heptane 48.67
    ethyl formate 1320.95
    1,2-dichloroethane 1970.23
    n-hexanol 355.78
    2-methoxyethanol 1877.81
    isobutyl acetate 386.81
    tetrachloromethane 483.51
    n-pentyl acetate 535.14
    transcutol 2216.58
    n-heptanol 259.14
    ethylbenzene 270.47
    MIBK 508.65
    2-propoxyethanol 799.67
    tert-butanol 791.21
    MTBE 654.12
    2-butoxyethanol 570.79
    propionic acid 1463.13
    o-xylene 279.69
    formic acid 2183.42
    diethyl ether 880.78
    m-xylene 232.9
    p-xylene 401.72
    chlorobenzene 880.99
    dimethyl carbonate 624.05
    n-octane 40.39
    formamide 3035.97
    cyclopentanone 1858.25
    2-pentanone 1046.46
    anisole 706.76
    cyclopentyl methyl ether 697.54
    gamma-butyrolactone 2878.94
    1-methoxy-2-propanol 1073.67
    pyridine 1597.36
    3-pentanone 908.43
    furfural 2808.32
    n-dodecane 35.53
    diethylene glycol 874.32
    diisopropyl ether 235.92
    tert-amyl alcohol 698.12
    acetylacetone 1414.02
    n-hexadecane 41.5
    acetophenone 794.95
    methyl propionate 1185.89
    isopentyl acetate 501.89
    trichloroethylene 3951.62
    n-nonanol 292.52
    cyclohexanol 562.73
    benzyl alcohol 661.21
    2-ethylhexanol 246.19
    isooctanol 220.74
    dipropyl ether 280.24
    1,2-dichlorobenzene 1003.25
    ethyl lactate 481.01
    propylene carbonate 1348.68
    n-methylformamide 2443.56
    2-pentanol 423.23
    n-pentane 80.19
    1-propoxy-2-propanol 495.74
    1-methoxy-2-propyl acetate 541.2
    2-(2-methoxypropoxy) propanol 468.36
    mesitylene 181.15
    ε-caprolactone 1563.7
    p-cymene 153.85
    epichlorohydrin 2628.05
    1,1,1-trichloroethane 1525.35
    2-aminoethanol 769.97
    morpholine-4-carbaldehyde 2266.83
    sulfolane 3174.19
    2,2,4-trimethylpentane 59.42
    2-methyltetrahydrofuran 1258.6
    n-hexyl acetate 751.59
    isooctane 40.01
    2-(2-butoxyethoxy)ethanol 746.18
    sec-butyl acetate 477.57
    tert-butyl acetate 677.46
    decalin 79.28
    glycerin 761.59
    diglyme 1530.69
    acrylic acid 1734.3
    isopropyl myristate 228.21
    n-butyric acid 1222.4
    acetyl acetate 944.68
    di(2-ethylhexyl) phthalate 212.39
    ethyl propionate 819.24
    nitromethane 6053.63
    1,2-diethoxyethane 770.35
    benzonitrile 1099.54
    trioctyl phosphate 187.98
    1-bromopropane 732.92
    gamma-valerolactone 2702.14
    n-decanol 216.86
    triethyl phosphate 252.41
    4-methyl-2-pentanol 225.42
    propionitrile 1262.86
    vinylene carbonate 1578.19
    1,1,2-trichlorotrifluoroethane 1921.11
    DMS 746.05
    cumene 202.71
    2-octanol 240.04
    2-hexanone 790.2
    octyl acetate 325.14
    limonene 204.97
    1,2-dimethoxyethane 1836.6
    ethyl orthosilicate 225.1
    tributyl phosphate 262.93
    diacetone alcohol 763.29
    N,N-dimethylaniline 460.34
    acrylonitrile 2161.19
    aniline 568.88
    1,3-propanediol 980.63
    bromobenzene 829.89
    dibromomethane 1659.49
    1,1,2,2-tetrachloroethane 2550.1
    2-methyl-cyclohexyl acetate 333.13
    tetrabutyl urea 324.01
    diisobutyl methanol 158.48
    2-phenylethanol 443.83
    styrene 396.89
    dioctyl adipate 335.13
    dimethyl sulfate 1114.35
    ethyl butyrate 493.42
    methyl lactate 612.8
    butyl lactate 418.73
    diethyl carbonate 370.81
    propanediol butyl ether 637.67
    triethyl orthoformate 310.38
    p-tert-butyltoluene 150.11
    methyl 4-tert-butylbenzoate 512.74
    morpholine 1904.08
    tert-butylamine 427.83
    n-dodecanol 160.4
    dimethoxymethane 1286.1
    ethylene carbonate 1236.72
    cyrene 476.33
    2-ethoxyethyl acetate 733.44
    2-ethylhexyl acetate 395.26
    1,2,4-trichlorobenzene 1129.74
    4-methylpyridine 1308.14
    dibutyl ether 345.83
    2,6-dimethyl-4-heptanol 158.48
    DEF 1323.75
    dimethyl isosorbide 768.98
    tetrachloroethylene 1909.27
    eugenol 560.62
    triacetin 684.62
    span 80 424.47
    1,4-butanediol 536.28
    1,1-dichloroethane 1579.24
    2-methyl-1-pentanol 438.47
    methyl formate 2140.79
    2-methyl-1-butanol 438.4
    n-decane 58.92
    butyronitrile 996.87
    3,7-dimethyl-1-octanol 282.55
    1-chlorooctane 236.75
    1-chlorotetradecane 95.42
    n-nonane 58.43
    undecane 44.62
    tert-butylcyclohexane 75.1
    cyclooctane 51.78
    cyclopentanol 702.9
    tetrahydropyran 1122.37
    tert-amyl methyl ether 514.13
    2,5,8-trioxanonane 871.86
    1-hexene 285.31
    2-isopropoxyethanol 805.72
    2,2,2-trifluoroethanol 1295.68
    methyl butyrate 1127.94

    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