2-Isobutyl-4,5-dimethyloxazole

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  • Identifiers

    CAS number
    26131-91-9

    Molecular formula
    C9H15NO

    SMILES
    CC1=C(OC(=N1)CC(C)C)C

  • Odor profile

    Fragrance
    Green 61.04%
    Roasted 54.52%
    Earthy 50.41%
    Vegetable 48.77%
    Burnt 48.04%
    Nutty 46.89%
    Herbal 38.11%
    Musty 34.18%
    Meaty 30.51%
    Cocoa 29.78%

     

    Flavor
    Roasted 55.31%
    Burnt 49.93%
    Earthy 45.03%
    Green 35.16%
    Earth 34.98%
    Vegetable 33.47%
    Musty 30.98%
    Meaty 28.08%
    Nutty 26.95%
    Hazelnut 26.53%

     

    Odor impact est.
    Medium

  • Properties

    XLogP3-AA
    2.8

    pKa est.
    7.6 (neutral)

    Molecular weight
    153.22 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Moderately fast

    Boiling point

    • 227.00 °C. @ 760.00 mm Hg

    Flash point

    • 69.35 ˚C est.

    Solubility expt.

    • Insoluble in water
    • Soluble (in ethanol)

  • Synonyms

    • 2-isobutyl-4,5-dimethyloxazole
    • 26131-91-9
    • 4,5-dimethyl-2-(2-methylpropyl)-1,3-oxazole
    • 4,5-Dimethyl-2-isobutyloxazole
    • Oxazole, 2-isobutyl-4,5-dimethyl-
    • 31DA09P920
    • 2-ISOBUTYL-4,5-DIMETHYL OXAZOLE
    • UNII-31DA09P920
    • FEMA NO. 4397
    • Oxazole, 4,5-dimethyl-2-(2-methylpropyl)-
    • 2-iso-Butyl-4,5-dimethyloxazole
    • DTXSID70865269
    • Oxazole, 4,5-dimethyl-2-isobutyl
    • 2-Isobutyl-4,5-dimethyl-1,3-oxazole
    • 2-ISOBUTYL-4,5-DIMETHYLOXAZOLE [FHFI]
    • SCHEMBL18339427
    • DTXCID40813696
    • CHEBI:193690
    • SNRVAFQIIFPYDR-UHFFFAOYSA-N
    • AKOS006271817
    • 2-Isobutyl-4,5-dimethyloxazole, 8CI
    • 4,5-Dimethyl-2-(2-methylpropyl)-Oxazole
    • Q27256039

  • Applications

    2-Isobutyl-4,5-dimethyloxazole (CAS 26131-91-9) is commonly used as an intermediate or building block in organic synthesis, supporting the preparation of pharmaceutical and agrochemical compounds. It also serves as a building block for specialty chemicals and materials development, including polymers and coatings. In the fragrance field, the compound may function as an odor-active intermediate or notes-bearing constituent for perfumery applications. Additionally, it is often used as a reagent in research and development to explore new synthetic routes. Use is subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 1167.57
    methanol 1368.2
    isopropanol 967.63
    water 9.79
    ethyl acetate 492.99
    n-propanol 967.07
    acetone 695.09
    n-butanol 945.84
    acetonitrile 736.9
    DMF 792.84
    toluene 569.94
    isobutanol 833.92
    1,4-dioxane 1372.48
    methyl acetate 485.65
    THF 1973.18
    2-butanone 567.2
    n-pentanol 682.67
    sec-butanol 952.56
    n-hexane 402.41
    ethylene glycol 191.52
    NMP 884.19
    cyclohexane 653.37
    DMSO 586.84
    n-butyl acetate 543.79
    n-octanol 609.1
    chloroform 3412.21
    n-propyl acetate 342.38
    acetic acid 901.97
    dichloromethane 2336.96
    cyclohexanone 1076.72
    propylene glycol 415.15
    isopropyl acetate 339.93
    DMAc 675.92
    2-ethoxyethanol 471.71
    isopentanol 743.04
    n-heptane 269.99
    ethyl formate 497.58
    1,2-dichloroethane 857.89
    n-hexanol 970.39
    2-methoxyethanol 792.42
    isobutyl acetate 285.67
    tetrachloromethane 582.66
    n-pentyl acetate 398.88
    transcutol 998.94
    n-heptanol 469.91
    ethylbenzene 383.6
    MIBK 334.87
    2-propoxyethanol 756.55
    tert-butanol 937.88
    MTBE 680.12
    2-butoxyethanol 475.09
    propionic acid 622.7
    o-xylene 360.45
    formic acid 276.08
    diethyl ether 618.3
    m-xylene 355.54
    p-xylene 591.17
    chlorobenzene 766.47
    dimethyl carbonate 199.91
    n-octane 123.82
    formamide 296.98
    cyclopentanone 1003.84
    2-pentanone 483.67
    anisole 457.81
    cyclopentyl methyl ether 791.87
    gamma-butyrolactone 1056.18
    1-methoxy-2-propanol 597.76
    pyridine 1142.45
    3-pentanone 364.64
    furfural 949.77
    n-dodecane 109.64
    diethylene glycol 433.01
    diisopropyl ether 243.76
    tert-amyl alcohol 867.47
    acetylacetone 445.71
    n-hexadecane 119.97
    acetophenone 405.53
    methyl propionate 394.72
    isopentyl acetate 486.56
    trichloroethylene 1693.27
    n-nonanol 490.03
    cyclohexanol 1034.82
    benzyl alcohol 487.96
    2-ethylhexanol 540.03
    isooctanol 363.22
    dipropyl ether 451.22
    1,2-dichlorobenzene 614.93
    ethyl lactate 205.74
    propylene carbonate 773.98
    n-methylformamide 443.17
    2-pentanol 638.66
    n-pentane 324.22
    1-propoxy-2-propanol 588.32
    1-methoxy-2-propyl acetate 401.36
    2-(2-methoxypropoxy) propanol 399.54
    mesitylene 234.85
    ε-caprolactone 901.92
    p-cymene 252.57
    epichlorohydrin 1049.4
    1,1,1-trichloroethane 1090.03
    2-aminoethanol 448.03
    morpholine-4-carbaldehyde 775.84
    sulfolane 947.81
    2,2,4-trimethylpentane 161.34
    2-methyltetrahydrofuran 1324.06
    n-hexyl acetate 704.13
    isooctane 98.92
    2-(2-butoxyethoxy)ethanol 550.86
    sec-butyl acetate 253.75
    tert-butyl acetate 357.76
    decalin 210.62
    glycerin 366.59
    diglyme 742.42
    acrylic acid 473.0
    isopropyl myristate 274.25
    n-butyric acid 908.57
    acetyl acetate 371.39
    di(2-ethylhexyl) phthalate 293.44
    ethyl propionate 300.37
    nitromethane 745.84
    1,2-diethoxyethane 450.9
    benzonitrile 727.77
    trioctyl phosphate 214.31
    1-bromopropane 859.03
    gamma-valerolactone 1127.34
    n-decanol 358.23
    triethyl phosphate 194.0
    4-methyl-2-pentanol 354.27
    propionitrile 657.31
    vinylene carbonate 740.88
    1,1,2-trichlorotrifluoroethane 730.51
    DMS 382.57
    cumene 266.51
    2-octanol 422.25
    2-hexanone 425.35
    octyl acetate 372.1
    limonene 365.93
    1,2-dimethoxyethane 879.77
    ethyl orthosilicate 198.24
    tributyl phosphate 253.16
    diacetone alcohol 388.15
    N,N-dimethylaniline 344.98
    acrylonitrile 635.79
    aniline 604.26
    1,3-propanediol 595.6
    bromobenzene 848.91
    dibromomethane 1758.17
    1,1,2,2-tetrachloroethane 1479.55
    2-methyl-cyclohexyl acetate 368.19
    tetrabutyl urea 307.01
    diisobutyl methanol 247.36
    2-phenylethanol 540.32
    styrene 448.14
    dioctyl adipate 358.93
    dimethyl sulfate 262.32
    ethyl butyrate 354.85
    methyl lactate 233.91
    butyl lactate 342.7
    diethyl carbonate 275.8
    propanediol butyl ether 556.32
    triethyl orthoformate 279.43
    p-tert-butyltoluene 242.68
    methyl 4-tert-butylbenzoate 415.35
    morpholine 1431.72
    tert-butylamine 752.23
    n-dodecanol 282.73
    dimethoxymethane 522.08
    ethylene carbonate 619.22
    cyrene 369.3
    2-ethoxyethyl acetate 381.11
    2-ethylhexyl acetate 416.76
    1,2,4-trichlorobenzene 711.9
    4-methylpyridine 1101.39
    dibutyl ether 520.83
    2,6-dimethyl-4-heptanol 247.36
    DEF 487.31
    dimethyl isosorbide 587.64
    tetrachloroethylene 997.05
    eugenol 388.59
    triacetin 440.63
    span 80 538.52
    1,4-butanediol 294.83
    1,1-dichloroethane 1147.01
    2-methyl-1-pentanol 642.57
    methyl formate 385.33
    2-methyl-1-butanol 775.49
    n-decane 173.63
    butyronitrile 909.2
    3,7-dimethyl-1-octanol 466.45
    1-chlorooctane 423.35
    1-chlorotetradecane 184.86
    n-nonane 180.61
    undecane 131.46
    tert-butylcyclohexane 187.44
    cyclooctane 191.6
    cyclopentanol 1091.59
    tetrahydropyran 1513.58
    tert-amyl methyl ether 510.02
    2,5,8-trioxanonane 524.11
    1-hexene 693.77
    2-isopropoxyethanol 338.11
    2,2,2-trifluoroethanol 280.96
    methyl butyrate 424.01

    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