1-(1H-Pyrazol-4-yl)-ethanone

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  • Identifiers

    CAS number
    25016-16-4

    Molecular formula
    C5H6N2O

    SMILES
    CC(=O)C1=CNN=C1

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Nutty 79.28%
    Roasted 66.65%
    Popcorn 61.99%
    Burnt 49.43%
    Hazelnut 44.3%
    Coffee 41.08%
    Caramellic 40.84%
    Musty 39.96%
    Cocoa 30.15%
    Earthy 28.51%

     

    Flavor
    Nutty 63.41%
    Popcorn 48.14%
    Sweet 47.24%
    Bitter 41.4%
    Bread 36.0%
    Musty 35.93%
    Corn 35.29%
    Tobacco 34.7%
    Cocoa 33.83%
    Coffee 32.94%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    -0.1

    pKa est.
    7.09 (neutral)

    Molecular weight
    110.11 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    360°C

    Flash point

    • 140.37 ˚C est.

  • Synonyms

    • 1-(1h-pyrazol-4-yl)-ethanone
    • RefChem:420093
    • 674-917-5
    • 1-(1H-Pyrazol-4-yl)ethanone
    • 25016-16-4
    • 4-Acetylpyrazole
    • 1-(1H-pyrazol-4-yl)ethan-1-one
    • Ethanone, 1-(1H-pyrazol-4-yl)-
    • MFCD09878739
    • 4-Acetyl-1H-pyrazole
    • Ketone, methyl pyrazol-4-yl
    • Ethanone, 1-(1H-pyrazol-4-yl)- (9CI)
    • 1-(4-Pyrazolyl)ethanone
    • orb3023311
    • SCHEMBL1641505
    • SCHEMBL1854004
    • SCHEMBL5269270
    • DTXSID30947878
    • 1-(1H-Pyrazol-4-yl)ethanone #
    • AKOS012024639
    • DS-13423
    • SY096884
    • DB-012290
    • CS-0044097
    • EN300-105455
    • 016A164
    • F036026
    • 25016-16-4

  • Applications

    1-(1H-Pyrazol-4-yl)-ethanone (CAS 25016-16-4) is primarily used as a versatile intermediate in organic synthesis, serving as a building block to access pyrazole-containing heterocycles. In pharmaceutical research and development, it is commonly employed to construct drug-like scaffolds through subsequent functionalization of the pyrazole ring. In agrochemical development, it is used as a precursor for pyrazole-based herbicides or fungicide candidates. It also supports broader synthetic programs as a starting point to access diverse heterocycles (imidazoles, triazoles, etc.) and related specialty chemicals. In materials and catalysis research, it can underpin the preparation of functionalized ligands and polymeric or coating components that incorporate the pyrazole motif. Additionally, it is used as a general research reagent and library-building block in academic settings and industrial labs to support exploratory synthesis and screening.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 57.4
    methanol 80.38
    isopropanol 47.8
    water 26.62
    ethyl acetate 25.42
    n-propanol 49.76
    acetone 69.58
    n-butanol 35.07
    acetonitrile 50.14
    DMF 263.96
    toluene 6.27
    isobutanol 38.4
    1,4-dioxane 52.7
    methyl acetate 41.62
    THF 81.65
    2-butanone 53.12
    n-pentanol 28.65
    sec-butanol 38.63
    n-hexane 1.18
    ethylene glycol 43.02
    NMP 193.73
    cyclohexane 0.64
    DMSO 161.53
    n-butyl acetate 10.32
    n-octanol 9.74
    chloroform 30.15
    n-propyl acetate 13.53
    acetic acid 63.68
    dichloromethane 29.09
    cyclohexanone 49.75
    propylene glycol 39.19
    isopropyl acetate 13.41
    DMAc 225.97
    2-ethoxyethanol 65.65
    isopentanol 28.95
    n-heptane 1.11
    ethyl formate 23.03
    1,2-dichloroethane 18.62
    n-hexanol 15.07
    2-methoxyethanol 114.2
    isobutyl acetate 10.15
    tetrachloromethane 5.18
    n-pentyl acetate 10.55
    transcutol 132.69
    n-heptanol 8.58
    ethylbenzene 3.22
    MIBK 19.21
    2-propoxyethanol 42.24
    tert-butanol 45.15
    MTBE 20.5
    2-butoxyethanol 25.31
    propionic acid 43.95
    o-xylene 7.08
    formic acid 81.49
    diethyl ether 21.48
    m-xylene 6.84
    p-xylene 5.73
    chlorobenzene 9.89
    dimethyl carbonate 23.2
    n-octane 0.48
    formamide 112.67
    cyclopentanone 72.01
    2-pentanone 31.89
    anisole 18.5
    cyclopentyl methyl ether 30.14
    gamma-butyrolactone 79.1
    1-methoxy-2-propanol 75.2
    pyridine 32.48
    3-pentanone 28.86
    furfural 77.51
    n-dodecane 0.56
    diethylene glycol 53.48
    diisopropyl ether 5.17
    tert-amyl alcohol 36.1
    acetylacetone 32.66
    n-hexadecane 0.62
    acetophenone 22.11
    methyl propionate 35.22
    isopentyl acetate 11.01
    trichloroethylene 38.27
    n-nonanol 9.31
    cyclohexanol 22.39
    benzyl alcohol 20.88
    2-ethylhexanol 8.7
    isooctanol 7.9
    dipropyl ether 9.55
    1,2-dichlorobenzene 10.85
    ethyl lactate 16.01
    propylene carbonate 31.22
    n-methylformamide 99.03
    2-pentanol 21.29
    n-pentane 1.17
    1-propoxy-2-propanol 27.07
    1-methoxy-2-propyl acetate 20.34
    2-(2-methoxypropoxy) propanol 37.06
    mesitylene 4.28
    ε-caprolactone 40.04
    p-cymene 3.97
    epichlorohydrin 65.11
    1,1,1-trichloroethane 17.69
    2-aminoethanol 65.69
    morpholine-4-carbaldehyde 128.65
    sulfolane 99.27
    2,2,4-trimethylpentane 1.28
    2-methyltetrahydrofuran 49.51
    n-hexyl acetate 15.71
    isooctane 0.82
    2-(2-butoxyethoxy)ethanol 43.41
    sec-butyl acetate 9.66
    tert-butyl acetate 15.69
    decalin 0.96
    glycerin 72.34
    diglyme 69.7
    acrylic acid 48.75
    isopropyl myristate 7.24
    n-butyric acid 33.02
    acetyl acetate 14.57
    di(2-ethylhexyl) phthalate 11.28
    ethyl propionate 14.43
    nitromethane 126.75
    1,2-diethoxyethane 22.87
    benzonitrile 19.52
    trioctyl phosphate 7.57
    1-bromopropane 10.52
    gamma-valerolactone 101.7
    n-decanol 7.01
    triethyl phosphate 10.0
    4-methyl-2-pentanol 12.69
    propionitrile 30.25
    vinylene carbonate 31.96
    1,1,2-trichlorotrifluoroethane 66.42
    DMS 19.38
    cumene 3.83
    2-octanol 6.44
    2-hexanone 20.77
    octyl acetate 9.97
    limonene 5.84
    1,2-dimethoxyethane 67.54
    ethyl orthosilicate 9.29
    tributyl phosphate 9.39
    diacetone alcohol 33.61
    N,N-dimethylaniline 17.25
    acrylonitrile 41.93
    aniline 21.09
    1,3-propanediol 58.56
    bromobenzene 6.77
    dibromomethane 15.38
    1,1,2,2-tetrachloroethane 29.51
    2-methyl-cyclohexyl acetate 12.19
    tetrabutyl urea 14.64
    diisobutyl methanol 6.4
    2-phenylethanol 14.03
    styrene 3.7
    dioctyl adipate 13.12
    dimethyl sulfate 48.14
    ethyl butyrate 10.59
    methyl lactate 32.8
    butyl lactate 13.71
    diethyl carbonate 9.11
    propanediol butyl ether 28.31
    triethyl orthoformate 10.76
    p-tert-butyltoluene 3.96
    methyl 4-tert-butylbenzoate 23.52
    morpholine 73.32
    tert-butylamine 22.02
    n-dodecanol 5.36
    dimethoxymethane 73.29
    ethylene carbonate 22.99
    cyrene 42.35
    2-ethoxyethyl acetate 20.1
    2-ethylhexyl acetate 8.66
    1,2,4-trichlorobenzene 16.63
    4-methylpyridine 37.62
    dibutyl ether 8.48
    2,6-dimethyl-4-heptanol 6.4
    DEF 50.09
    dimethyl isosorbide 48.56
    tetrachloroethylene 18.44
    eugenol 25.17
    triacetin 24.09
    span 80 23.21
    1,4-butanediol 30.64
    1,1-dichloroethane 20.39
    2-methyl-1-pentanol 23.84
    methyl formate 56.22
    2-methyl-1-butanol 30.91
    n-decane 0.84
    butyronitrile 26.03
    3,7-dimethyl-1-octanol 10.49
    1-chlorooctane 3.84
    1-chlorotetradecane 1.89
    n-nonane 0.71
    undecane 0.67
    tert-butylcyclohexane 1.17
    cyclooctane 0.33
    cyclopentanol 38.86
    tetrahydropyran 29.9
    tert-amyl methyl ether 17.98
    2,5,8-trioxanonane 58.54
    1-hexene 4.69
    2-isopropoxyethanol 38.4
    2,2,2-trifluoroethanol 43.32
    methyl butyrate 19.45

    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