5-Ethyl-1,3-oxazole

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  • Identifiers

    CAS number
    32999-02-3

    Molecular formula
    C5H7NO

    SMILES
    CCC1=CN=CO1

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Nutty 65.85%
    Roasted 60.36%
    Green 56.88%
    Burnt 47.89%
    Musty 43.82%
    Coffee 43.33%
    Earthy 42.07%
    Sweet 41.57%
    Cocoa 40.25%
    Ethereal 38.33%

     

    Flavor
    Nutty 63.51%
    Sweet 56.2%
    Green 47.08%
    Earthy 44.95%
    Coffee 41.59%
    Vegetable 37.7%
    Roasted 37.58%
    Caramel 36.05%
    Musty 31.93%
    Peanut 31.33%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    1.2

    pKa est.
    6.04 (neutral)

    Molecular weight
    97.12 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Boiling point est.
    120°C

    Flash point

    • 31.68 ˚C est.

  • Synonyms

    • 5-ethyl-1,3-oxazole
    • RefChem:535459
    • 963-709-2
    • 5-Ethyloxazole
    • 32999-02-3
    • Oxazole, 5-ethyl-
    • 5-ETHYL OXAZOLE
    • 5-ethyl-oxazole
    • MFCD18968104
    • SCHEMBL355690
    • SCHEMBL357551
    • SCHEMBL357552
    • SCHEMBL1016848
    • SCHEMBL1978239
    • SCHEMBL9902805
    • DTXSID90480756
    • AKOS022183438
    • DB-317679
    • C77473
    • EN300-300151
    • 32999-02-3

  • Applications

    5-Ethyl-1,3-oxazole (CAS 32999-02-3) primarily serves as a synthetic intermediate and building block in organic synthesis. It is commonly used in medicinal chemistry and agrochemical research to access a range of heterocyclic compounds. The structure is employed as a starting point for the preparation of functionalized oxazole derivatives, enabling exploration of pharmaceutical leads and agrochemical candidates. In polymer and materials chemistry, it can be used as a precursor for functionalized oxazole-containing monomers or scaffolds, contributing to specialty polymers and coatings. It is also of interest in electronic and optoelectronic materials development as a heteroaromatic building block, potentially supporting the design of dyes, ligands, or light-emitting materials. Overall, use is typically as an intermediate, with application scope depending on formulation and regulatory considerations.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 620.89
    methanol 1126.64
    isopropanol 334.06
    water 26.51
    ethyl acetate 257.43
    n-propanol 378.88
    acetone 392.47
    n-butanol 353.55
    acetonitrile 438.96
    DMF 588.5
    toluene 167.86
    isobutanol 314.72
    1,4-dioxane 439.54
    methyl acetate 282.1
    THF 619.28
    2-butanone 310.75
    n-pentanol 284.46
    sec-butanol 302.35
    n-hexane 51.43
    ethylene glycol 159.34
    NMP 603.17
    cyclohexane 57.42
    DMSO 639.12
    n-butyl acetate 207.0
    n-octanol 109.91
    chloroform 1080.07
    n-propyl acetate 157.24
    acetic acid 808.84
    dichloromethane 1198.84
    cyclohexanone 412.26
    propylene glycol 127.02
    isopropyl acetate 140.13
    DMAc 450.49
    2-ethoxyethanol 356.99
    isopentanol 297.71
    n-heptane 34.39
    ethyl formate 239.27
    1,2-dichloroethane 504.64
    n-hexanol 204.89
    2-methoxyethanol 540.59
    isobutyl acetate 108.38
    tetrachloromethane 223.73
    n-pentyl acetate 145.9
    transcutol 852.87
    n-heptanol 108.01
    ethylbenzene 78.44
    MIBK 160.09
    2-propoxyethanol 317.42
    tert-butanol 359.41
    MTBE 268.59
    2-butoxyethanol 192.59
    propionic acid 350.68
    o-xylene 116.69
    formic acid 528.43
    diethyl ether 275.68
    m-xylene 110.34
    p-xylene 126.66
    chlorobenzene 307.35
    dimethyl carbonate 104.02
    n-octane 15.26
    formamide 474.37
    cyclopentanone 493.84
    2-pentanone 247.08
    anisole 193.98
    cyclopentyl methyl ether 273.91
    gamma-butyrolactone 566.11
    1-methoxy-2-propanol 304.01
    pyridine 485.15
    3-pentanone 182.64
    furfural 595.21
    n-dodecane 14.06
    diethylene glycol 269.73
    diisopropyl ether 81.87
    tert-amyl alcohol 325.41
    acetylacetone 252.31
    n-hexadecane 15.33
    acetophenone 179.42
    methyl propionate 201.85
    isopentyl acetate 179.88
    trichloroethylene 897.26
    n-nonanol 96.25
    cyclohexanol 256.15
    benzyl alcohol 188.72
    2-ethylhexanol 119.29
    isooctanol 94.09
    dipropyl ether 122.5
    1,2-dichlorobenzene 259.76
    ethyl lactate 86.41
    propylene carbonate 267.23
    n-methylformamide 382.34
    2-pentanol 214.03
    n-pentane 55.42
    1-propoxy-2-propanol 196.83
    1-methoxy-2-propyl acetate 163.79
    2-(2-methoxypropoxy) propanol 191.95
    mesitylene 76.46
    ε-caprolactone 323.58
    p-cymene 64.59
    epichlorohydrin 590.34
    1,1,1-trichloroethane 458.12
    2-aminoethanol 277.12
    morpholine-4-carbaldehyde 478.35
    sulfolane 612.52
    2,2,4-trimethylpentane 38.13
    2-methyltetrahydrofuran 486.6
    n-hexyl acetate 183.62
    isooctane 24.7
    2-(2-butoxyethoxy)ethanol 251.52
    sec-butyl acetate 100.59
    tert-butyl acetate 157.92
    decalin 31.84
    glycerin 181.3
    diglyme 411.24
    acrylic acid 360.32
    isopropyl myristate 77.92
    n-butyric acid 391.84
    acetyl acetate 176.0
    di(2-ethylhexyl) phthalate 95.14
    ethyl propionate 126.71
    nitromethane 740.58
    1,2-diethoxyethane 270.01
    benzonitrile 303.75
    trioctyl phosphate 62.76
    1-bromopropane 336.85
    gamma-valerolactone 555.2
    n-decanol 72.68
    triethyl phosphate 78.73
    4-methyl-2-pentanol 121.62
    propionitrile 325.73
    vinylene carbonate 272.87
    1,1,2-trichlorotrifluoroethane 400.18
    DMS 148.13
    cumene 67.69
    2-octanol 81.04
    2-hexanone 184.5
    octyl acetate 97.57
    limonene 95.01
    1,2-dimethoxyethane 407.25
    ethyl orthosilicate 77.87
    tributyl phosphate 85.69
    diacetone alcohol 184.17
    N,N-dimethylaniline 141.52
    acrylonitrile 397.82
    aniline 271.68
    1,3-propanediol 333.73
    bromobenzene 320.18
    dibromomethane 710.11
    1,1,2,2-tetrachloroethane 583.53
    2-methyl-cyclohexyl acetate 121.55
    tetrabutyl urea 105.94
    diisobutyl methanol 74.28
    2-phenylethanol 162.84
    styrene 116.65
    dioctyl adipate 110.61
    dimethyl sulfate 173.39
    ethyl butyrate 140.87
    methyl lactate 111.63
    butyl lactate 103.66
    diethyl carbonate 101.4
    propanediol butyl ether 168.26
    triethyl orthoformate 101.41
    p-tert-butyltoluene 60.58
    methyl 4-tert-butylbenzoate 156.1
    morpholine 492.49
    tert-butylamine 259.92
    n-dodecanol 56.34
    dimethoxymethane 308.06
    ethylene carbonate 212.56
    cyrene 185.91
    2-ethoxyethyl acetate 193.3
    2-ethylhexyl acetate 137.82
    1,2,4-trichlorobenzene 296.12
    4-methylpyridine 450.35
    dibutyl ether 125.66
    2,6-dimethyl-4-heptanol 74.28
    DEF 289.09
    dimethyl isosorbide 285.33
    tetrachloroethylene 456.97
    eugenol 171.49
    triacetin 170.0
    span 80 163.9
    1,4-butanediol 169.8
    1,1-dichloroethane 535.3
    2-methyl-1-pentanol 246.92
    methyl formate 277.08
    2-methyl-1-butanol 302.99
    n-decane 20.5
    butyronitrile 338.84
    3,7-dimethyl-1-octanol 118.03
    1-chlorooctane 74.29
    1-chlorotetradecane 34.29
    n-nonane 20.14
    undecane 16.4
    tert-butylcyclohexane 34.85
    cyclooctane 20.46
    cyclopentanol 317.09
    tetrahydropyran 387.53
    tert-amyl methyl ether 203.87
    2,5,8-trioxanonane 315.53
    1-hexene 142.21
    2-isopropoxyethanol 224.36
    2,2,2-trifluoroethanol 256.98
    methyl butyrate 188.62

    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