Benzoxazole

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  • Identifiers

    CAS number
    273-53-0

    Molecular formula
    C7H5NO

    SMILES
    C1=CC=C2C(=C1)N=CO2

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Sweet 64.1%
    Burnt 62.24%
    Nutty 51.69%
    Musty 43.43%
    Pungent 41.36%
    Meaty 40.48%
    Tobacco 40.45%
    Coffee 38.83%
    Earthy 37.94%
    Smoky 37.81%

     

    Flavor
    Nutty 60.13%
    Coffee 54.39%
    Tobacco 39.0%
    Sweet 38.6%
    Bitter 37.86%
    Musty 37.7%
    Vegetable 37.35%
    Rubber 36.81%
    Roasted 36.34%
    Green 34.53%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    1.6

    pKa est.
    6.14 (neutral)

    Molecular weight
    119.12 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Fast

    Boiling point est.
    192°C

    Flash point

    • 75.81 ˚C est.

  • Synonyms

    • BENZOXAZOLE
    • 273-53-0
    • 1,3-Benzoxazole
    • 1-Oxa-3-azaindene
    • 1-Oxa-3-aza-1H-indene
    • Benzoxazoles
    • J233Y1I55I
    • NSC-3982
    • DTXSID8059768
    • CHEBI:38814
    • RefChem:388827
    • DTXCID5037654
    • CHEBI:46700
    • 205-988-9
    • BENZO[D]OXAZOLE
    • Benzooxazole
    • USAF EK-5017
    • MFCD00005765
    • NSC 3982
    • EINECS 205-988-9
    • UNII-J233Y1I55I
    • AI3-05743
    • NSC3982
    • Benzoxazole, 98%
    • 1,3-Benzoxazole #
    • SCHEMBL2223
    • SCHEMBL5739
    • SCHEMBL7903
    • WLN: T56 BN DOJ
    • SCHEMBL23760
    • SCHEMBL29650
    • SCHEMBL30243
    • SCHEMBL449019
    • SCHEMBL449146
    • SCHEMBL449332
    • SCHEMBL449606
    • SCHEMBL450391
    • SCHEMBL451671
    • SCHEMBL452118
    • SCHEMBL452230
    • SCHEMBL452537
    • SCHEMBL455413
    • CHEMBL451894
    • orb3029980
    • SCHEMBL2724328
    • SCHEMBL5398832
    • AKOS000119993
    • CS-W004722
    • PS-3680
    • DB-029474
    • A3423
    • B0095
    • NS00028287
    • EN300-20396
    • H10149
    • A819031
    • F078910
    • Q761111
    • InChI=1/C7H5NO/c1-2-4-7-6(3-1)8-5-9-7/h1-5
    • 273-53-0

  • Applications

    Benzoxazole (CAS 273-53-0) is a versatile heterocycle used as a synthetic building block in pharmaceutical and agrochemical development, where it often serves as a core scaffold for heterocyclic intermediates. It also functions as a key precursor in dye and pigment synthesis, delivering chromophore-containing compounds for coloration. In polymer chemistry, it is a building unit for high-temperature polymers such as polybenzoxazole, which enable durable coatings, fibers, and electronic/optical components. Additionally, benzoxazole derivatives are explored for organic electronic and fluorescent material applications, including sensors and optoelectronic devices.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 284.67
    methanol 450.01
    isopropanol 197.6
    water 8.16
    ethyl acetate 109.54
    n-propanol 227.53
    acetone 168.65
    n-butanol 188.82
    acetonitrile 119.48
    DMF 333.87
    toluene 32.07
    isobutanol 180.62
    1,4-dioxane 154.04
    methyl acetate 97.93
    THF 358.1
    2-butanone 132.35
    n-pentanol 189.89
    sec-butanol 187.76
    n-hexane 24.38
    ethylene glycol 99.06
    NMP 165.78
    cyclohexane 14.4
    DMSO 319.38
    n-butyl acetate 47.82
    n-octanol 50.19
    chloroform 162.77
    n-propyl acetate 71.35
    acetic acid 191.51
    dichloromethane 219.48
    cyclohexanone 113.74
    propylene glycol 74.66
    isopropyl acetate 66.16
    DMAc 164.9
    2-ethoxyethanol 267.45
    isopentanol 157.16
    n-heptane 15.17
    ethyl formate 83.32
    1,2-dichloroethane 140.79
    n-hexanol 82.38
    2-methoxyethanol 331.22
    isobutyl acetate 50.06
    tetrachloromethane 31.75
    n-pentyl acetate 57.4
    transcutol 686.03
    n-heptanol 46.49
    ethylbenzene 24.94
    MIBK 90.38
    2-propoxyethanol 153.33
    tert-butanol 163.55
    MTBE 105.24
    2-butoxyethanol 102.88
    propionic acid 116.29
    o-xylene 26.46
    formic acid 163.19
    diethyl ether 197.44
    m-xylene 27.8
    p-xylene 31.28
    chlorobenzene 50.62
    dimethyl carbonate 56.48
    n-octane 8.03
    formamide 269.08
    cyclopentanone 169.69
    2-pentanone 132.47
    anisole 82.29
    cyclopentyl methyl ether 135.86
    gamma-butyrolactone 174.34
    1-methoxy-2-propanol 228.47
    pyridine 140.39
    3-pentanone 91.08
    furfural 166.34
    n-dodecane 6.55
    diethylene glycol 143.98
    diisopropyl ether 47.77
    tert-amyl alcohol 138.53
    acetylacetone 107.06
    n-hexadecane 7.04
    acetophenone 69.74
    methyl propionate 97.86
    isopentyl acetate 48.62
    trichloroethylene 191.1
    n-nonanol 47.3
    cyclohexanol 94.95
    benzyl alcohol 83.66
    2-ethylhexanol 46.45
    isooctanol 44.23
    dipropyl ether 71.26
    1,2-dichlorobenzene 49.33
    ethyl lactate 50.56
    propylene carbonate 81.28
    n-methylformamide 216.66
    2-pentanol 142.97
    n-pentane 26.93
    1-propoxy-2-propanol 95.0
    1-methoxy-2-propyl acetate 67.04
    2-(2-methoxypropoxy) propanol 118.76
    mesitylene 20.11
    ε-caprolactone 97.43
    p-cymene 18.26
    epichlorohydrin 239.99
    1,1,1-trichloroethane 71.62
    2-aminoethanol 166.16
    morpholine-4-carbaldehyde 199.72
    sulfolane 184.96
    2,2,4-trimethylpentane 11.13
    2-methyltetrahydrofuran 203.78
    n-hexyl acetate 77.27
    isooctane 9.11
    2-(2-butoxyethoxy)ethanol 182.24
    sec-butyl acetate 52.28
    tert-butyl acetate 70.54
    decalin 9.82
    glycerin 112.48
    diglyme 290.38
    acrylic acid 107.3
    isopropyl myristate 40.21
    n-butyric acid 134.01
    acetyl acetate 49.51
    di(2-ethylhexyl) phthalate 35.89
    ethyl propionate 68.74
    nitromethane 227.67
    1,2-diethoxyethane 163.65
    benzonitrile 68.04
    trioctyl phosphate 27.43
    1-bromopropane 100.99
    gamma-valerolactone 176.34
    n-decanol 37.31
    triethyl phosphate 31.93
    4-methyl-2-pentanol 72.94
    propionitrile 119.68
    vinylene carbonate 75.11
    1,1,2-trichlorotrifluoroethane 120.06
    DMS 64.05
    cumene 23.77
    2-octanol 38.55
    2-hexanone 95.06
    octyl acetate 45.46
    limonene 25.77
    1,2-dimethoxyethane 261.47
    ethyl orthosilicate 31.97
    tributyl phosphate 36.04
    diacetone alcohol 106.2
    N,N-dimethylaniline 61.83
    acrylonitrile 123.73
    aniline 75.5
    1,3-propanediol 186.06
    bromobenzene 41.44
    dibromomethane 137.04
    1,1,2,2-tetrachloroethane 125.86
    2-methyl-cyclohexyl acetate 45.42
    tetrabutyl urea 46.84
    diisobutyl methanol 33.58
    2-phenylethanol 56.2
    styrene 32.63
    dioctyl adipate 52.67
    dimethyl sulfate 77.04
    ethyl butyrate 53.13
    methyl lactate 64.78
    butyl lactate 52.37
    diethyl carbonate 39.86
    propanediol butyl ether 100.99
    triethyl orthoformate 42.78
    p-tert-butyltoluene 17.13
    methyl 4-tert-butylbenzoate 66.78
    morpholine 209.35
    tert-butylamine 110.29
    n-dodecanol 30.81
    dimethoxymethane 248.8
    ethylene carbonate 61.05
    cyrene 89.77
    2-ethoxyethyl acetate 91.07
    2-ethylhexyl acetate 36.62
    1,2,4-trichlorobenzene 52.3
    4-methylpyridine 93.5
    dibutyl ether 73.78
    2,6-dimethyl-4-heptanol 33.58
    DEF 140.42
    dimethyl isosorbide 147.18
    tetrachloroethylene 103.52
    eugenol 85.35
    triacetin 84.75
    span 80 80.76
    1,4-butanediol 113.88
    1,1-dichloroethane 100.46
    2-methyl-1-pentanol 141.66
    methyl formate 131.4
    2-methyl-1-butanol 158.56
    n-decane 9.94
    butyronitrile 122.46
    3,7-dimethyl-1-octanol 54.5
    1-chlorooctane 29.23
    1-chlorotetradecane 14.83
    n-nonane 9.58
    undecane 7.71
    tert-butylcyclohexane 10.09
    cyclooctane 7.21
    cyclopentanol 133.62
    tetrahydropyran 154.25
    tert-amyl methyl ether 87.86
    2,5,8-trioxanonane 209.27
    1-hexene 70.02
    2-isopropoxyethanol 169.89
    2,2,2-trifluoroethanol 69.81
    methyl butyrate 85.26

    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