Mesityl oxide

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  • Identifiers

    CAS number
    141-79-7

    Molecular formula
    C6H10O

    SMILES
    CC(=CC(=O)C)C

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

    Retention indicies (RI)

    • Carbowax: 1118.0

  • Odor profile

    Sweet 57.35%
    Mint 56.53%
    Pungent 54.86%
    Nutty 53.71%
    Musty 53.1%
    Woody 51.6%
    Herbal 50.79%
    Green 47.85%
    Ketonic 47.59%
    Earthy 47.31%

    Scent© AI

    Odor threshold>

    • Odor Threshold Low: 0.01 [mmHg]. Odor Threshold High: 12.0 [mmHg]. Detection odor threshold from AIHA (mean = 0.017 ppm)
    • Odor low: 0.068 mg/cu m; Odor high: 100 mg/cu m.
    • Odor threshold values: 50% detection: 12 ppm; 100% detection: 25 ppm.
    • The absolute perception limit has been reported to be 0.017 ppm.

  • Properties

    XLogP3-AA
    1.4

    Molecular weight
    98.14 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Melting point expt.

    • -51 °F (USCG, 1999)
    • -59 °C
    • MP: -41.5 °C (also reported as -59 °C); can be made to crystallize at low temp in petroleum ether
    • -41.5 °C
    • -52 °F

    Boiling point

    • 266 °F at 760 mmHg (USCG, 1999)
    • 130 °C at 760 mm Hg
    • 130 °C
    • 266 °F

    Flash point est.
    22.85 ˚C

    Flash point expt.

    • 73 °F (USCG, 1999)
    • 31 °C
    • 87 °F (31 °C) (Closed cup)
    • 25 °C c.c.
    • 87 °F

    Solubility expt.

    • 3 % (NIOSH, 2024)
    • Sol in about 30 parts water; miscible with most org liq
    • Miscible in ethanol, ethyl ether
    • SLIGHTLY SOL IN PROPYLENE GLYCOL
    • In water, 28,900 mg/L at 20 °C
    • 28.9 mg/mL at 20 °C
    • Solubility in water, g/100ml at 20 °C: 3.0 (moderate)
    • slightly soluble inwater; miscible in organic solvents
    • Miscible at room temperature (in ethanol)
    • 3%

  • Synonyms

    • MESITYL OXIDE
    • 141-79-7
    • 4-Methylpent-3-en-2-one
    • 4-Methyl-3-penten-2-one
    • 3-Penten-2-one, 4-methyl-
    • Methyl isobutenyl ketone
    • Isopropylideneacetone
    • Isobutenyl methyl ketone
    • Mesityloxid
    • Mesityloxyde
    • Ossido di mesitile
    • 3-Isohexen-2-one
    • Isopropylidene acetone
    • Oxyde de mesityle
    • Acetone, isopropylidene-
    • Methyl 2-methyl-1-propenyl ketone
    • Methyl 2,2-dimethylvinyl ketone
    • 2-Methyl-4-oxo-2-pentene
    • 2-Methyl-2-pentenone-4
    • 4-Metil-3-penten-2-one
    • 2,2-Dimethylvinyl methyl ketone
    • 4-Methyl-3-pentene-2-one
    • 4-Methyl-3-penten-2-on
    • Mesityloxid [German]
    • Mesityloxyde [Dutch]
    • 2-Methyl-2-penten-4-one
    • Caswell No. 547
    • FEMA No. 3368
    • FEMA Number 3368
    • Oxyde de mesityle [French]
    • Ossido di mesitile [Italian]
    • NSC 38717
    • HSDB 1195
    • 4-Methyl-3-penten-2-one, 9CI
    • EINECS 205-502-5
    • 4-Metil-3-penten-2-one [Italian]
    • UN1229
    • EPA Pesticide Chemical Code 052401
    • BRN 1361550
    • Isopropylidene-Acetone
    • DTXSID1029170
    • 4-Methyl-3-penten-2-on [Dutch, German]
    • AI3-07702
    • (CH3)2C=CHC(=O)CH3
    • NSC-38717
    • 77LAC84669
    • MESITYL OXIDE [MI]
    • 1-Methylpent-2-en-4-one
    • 4-methyl-pent-3-en-2-one
    • MESITYL OXIDE [HSDB]
    • DTXCID209170
    • CHEBI:89993
    • FEMA 3368
    • EC 205-502-5
    • 4-Methyl-3-penten-2-one (mesityl oxide)
    • 4-METHYL-3-PENTENE-2-ONE [FHFI]
    • TEICOPLANIN IMPURITY A [EP IMPURITY]
    • 3-PENTEN,2-ONE,4-METHYL MESITYLOXIDE
    • MESITYLOXID (GERMAN)
    • MESITYLOXYDE (DUTCH)
    • CILASTATIN SODIUM IMPURITY D [EP IMPURITY]
    • OXYDE DE MESITYLE (FRENCH)
    • OSSIDO DI MESITILE (ITALIAN)
    • CAS-141-79-7
    • 4-METIL-3-PENTEN-2-ONE (ITALIAN)
    • TEICOPLANIN IMPURITY A (EP IMPURITY)
    • 4-Methyl-3-penten-2-on (DUTCH, GERMAN)
    • 1-ISOBUTENYL METHYL KETONE (MESITYL OXIDE)
    • 1-ISOBUTENYL METHYL KETONE {MESITYL OXIDE}
    • CILASTATIN SODIUM IMPURITY D (EP IMPURITY)
    • 1-Isobutenyl methyl ketone
    • 3Isohexen2one
    • 4-Methylpent-3-en-2-one; Mesityl oxide; Cilastatin Sodium Imp. D (EP)
    • UNII-77LAC84669
    • 4Methyl3penten2on
    • 4Metil3penten2one
    • 2Methyl2pentenone4
    • 4Methyl3penten2one
    • Mesityloxid(german)
    • 2Methyl4oxo2pentene
    • MFCD00008900
    • Acetone, isopropylidene
    • 3Penten2one, 4methyl
    • Mesityl oxide [UN1229] [Flammable liquid]
    • 2-methylpent-2-en-4-one
    • Mesityl oxide (ACGIH:OSHA)
    • Methyl 2methyl1propenyl ketone
    • 2,2Dimethylvinyl methyl ketone
    • Methyl 2,2dimethylvinyl ketone
    • CHEMBL3185916
    • WLN: 1Y1 & U1V1
    • 4-Methyl-3-penten-2-one, 90%
    • NSC38717
    • Tox21_202080
    • Tox21_303606
    • LMFA12000030
    • STL146350
    • Mesityl oxide, technical grade, 90%
    • AKOS000118892
    • FM00482
    • UN 1229
    • NCGC00249161-01
    • NCGC00257514-01
    • NCGC00259629-01
    • 4-Methyl-3-penten-2-on(DUTCH, GERMAN)
    • M0069
    • M1340
    • NS00006985
    • EN300-21333
    • Mesityl oxide [UN1229] [Flammable liquid]
    • 3-PENTEN,2-ONE,4-METHYL MESITYLOXIDE
    • A807813
    • Q425668
    • 4-Methyl-3-penten-2-one, analytical reference material
    • Mesityl oxide, 99%, mixture of alpha and beta isomers
    • Mesityl oxide, European Pharmacopoeia (EP) Reference Standard
    • MESITYL OXIDE, MIXTURE OF ALPHA-AND BETA-ISOMERS (CA 93% ALPHA)
    • Mesityl Oxide, Pharmaceutical Secondary Standard; Certified Reference Material
    • Mesityl oxide, suitable for neutral marker for measuring electroosmotic flow (EOF), ~98%
    • Methyl 2,2-dimethylvinyl ketone;Methyl isobutenyl ketone;Isopropylideneacetone
    • 205-502-5

  • Applications

    Mesityl oxide (CAS 141-79-7) is an α,β-unsaturated ketone used primarily as an industrial solvent with a medium evaporation rate and strong solvency for nitrocellulose, acrylic, alkyd, epoxy and phenolic resins in coatings, printing inks, adhesives, metal-cleaning formulations and extraction/crystallization processes; it is also a key intermediate in acetone chemistry, hydrogenating to methyl isobutyl ketone (MIBK) and further to methyl isobutyl carbinol (MIBC), and serving as a versatile Michael acceptor and condensation partner to build fine chemicals for pharmaceuticals, agrochemicals, UV‑curable materials and specialty coatings; additionally, it is employed as a viscosity-control/process solvent to improve flow and dry of high-solids coatings and as a carrier in degreasers, adhesive removers and large-scale synthesis.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 1742.0
    methanol 2059.32
    isopropanol 1454.77
    water 77.38
    ethyl acetate 1120.12
    n-propanol 1455.0
    acetone 1335.46
    n-butanol 1335.97
    acetonitrile 1265.15
    DMF 1075.11
    toluene 554.97
    isobutanol 1079.0
    1,4-dioxane 1669.31
    methyl acetate 1092.16
    THF 2354.54
    2-butanone 983.43
    n-pentanol 787.02
    sec-butanol 1387.34
    n-hexane 1088.91
    ethylene glycol 549.46
    NMP 1418.51
    cyclohexane 1065.17
    DMSO 582.68
    n-butyl acetate 712.49
    n-octanol 826.08
    chloroform 1912.21
    n-propyl acetate 519.87
    acetic acid 2121.23
    dichloromethane 1294.29
    cyclohexanone 1381.07
    propylene glycol 697.46
    isopropyl acetate 663.54
    DMAc 993.48
    2-ethoxyethanol 715.85
    isopentanol 928.92
    n-heptane 690.39
    ethyl formate 678.69
    1,2-dichloroethane 788.7
    n-hexanol 1651.74
    2-methoxyethanol 1397.22
    isobutyl acetate 332.18
    tetrachloromethane 620.71
    n-pentyl acetate 466.77
    transcutol 1753.52
    n-heptanol 592.45
    ethylbenzene 343.98
    MIBK 561.16
    2-propoxyethanol 1409.44
    tert-butanol 1631.78
    MTBE 1221.59
    2-butoxyethanol 637.46
    propionic acid 1318.57
    o-xylene 413.46
    formic acid 800.81
    diethyl ether 1529.11
    m-xylene 450.02
    p-xylene 413.15
    chlorobenzene 531.86
    dimethyl carbonate 347.07
    n-octane 206.37
    formamide 504.56
    cyclopentanone 1260.34
    2-pentanone 949.07
    anisole 466.26
    cyclopentyl methyl ether 1531.61
    gamma-butyrolactone 1418.19
    1-methoxy-2-propanol 1091.05
    pyridine 777.78
    3-pentanone 765.23
    furfural 855.21
    n-dodecane 137.52
    diethylene glycol 872.97
    diisopropyl ether 564.71
    tert-amyl alcohol 1371.16
    acetylacetone 781.82
    n-hexadecane 145.09
    acetophenone 365.17
    methyl propionate 844.93
    isopentyl acetate 567.32
    trichloroethylene 1221.23
    n-nonanol 664.94
    cyclohexanol 1541.5
    benzyl alcohol 393.4
    2-ethylhexanol 853.93
    isooctanol 419.03
    dipropyl ether 893.96
    1,2-dichlorobenzene 438.15
    ethyl lactate 292.84
    propylene carbonate 809.83
    n-methylformamide 768.81
    2-pentanol 1084.89
    n-pentane 843.41
    1-propoxy-2-propanol 999.85
    1-methoxy-2-propyl acetate 617.68
    2-(2-methoxypropoxy) propanol 531.37
    mesitylene 310.22
    ε-caprolactone 1176.58
    p-cymene 253.29
    epichlorohydrin 1133.18
    1,1,1-trichloroethane 1176.2
    2-aminoethanol 840.85
    morpholine-4-carbaldehyde 1196.13
    sulfolane 1063.01
    2,2,4-trimethylpentane 285.34
    2-methyltetrahydrofuran 1870.53
    n-hexyl acetate 986.76
    isooctane 219.54
    2-(2-butoxyethoxy)ethanol 765.73
    sec-butyl acetate 382.26
    tert-butyl acetate 700.06
    decalin 326.61
    glycerin 749.77
    diglyme 1039.22
    acrylic acid 993.94
    isopropyl myristate 347.92
    n-butyric acid 1381.3
    acetyl acetate 722.18
    di(2-ethylhexyl) phthalate 267.85
    ethyl propionate 541.72
    nitromethane 1556.06
    1,2-diethoxyethane 656.46
    benzonitrile 474.28
    trioctyl phosphate 233.32
    1-bromopropane 890.31
    gamma-valerolactone 1382.16
    n-decanol 460.81
    triethyl phosphate 225.54
    4-methyl-2-pentanol 518.43
    propionitrile 889.61
    vinylene carbonate 654.42
    1,1,2-trichlorotrifluoroethane 875.17
    DMS 492.28
    cumene 253.37
    2-octanol 472.36
    2-hexanone 583.24
    octyl acetate 476.07
    limonene 500.85
    1,2-dimethoxyethane 1062.11
    ethyl orthosilicate 236.08
    tributyl phosphate 270.68
    diacetone alcohol 719.87
    N,N-dimethylaniline 346.04
    acrylonitrile 775.33
    aniline 574.18
    1,3-propanediol 958.36
    bromobenzene 494.54
    dibromomethane 1111.59
    1,1,2,2-tetrachloroethane 1069.48
    2-methyl-cyclohexyl acetate 415.92
    tetrabutyl urea 349.25
    diisobutyl methanol 372.95
    2-phenylethanol 514.92
    styrene 346.86
    dioctyl adipate 393.84
    dimethyl sulfate 393.62
    ethyl butyrate 473.36
    methyl lactate 426.97
    butyl lactate 354.34
    diethyl carbonate 301.54
    propanediol butyl ether 646.46
    triethyl orthoformate 339.18
    p-tert-butyltoluene 259.4
    methyl 4-tert-butylbenzoate 447.34
    morpholine 1807.88
    tert-butylamine 1313.28
    n-dodecanol 343.36
    dimethoxymethane 948.55
    ethylene carbonate 619.73
    cyrene 408.42
    2-ethoxyethyl acetate 493.41
    2-ethylhexyl acetate 468.73
    1,2,4-trichlorobenzene 502.78
    4-methylpyridine 890.44
    dibutyl ether 712.67
    2,6-dimethyl-4-heptanol 372.95
    DEF 921.53
    dimethyl isosorbide 738.02
    tetrachloroethylene 817.77
    eugenol 406.59
    triacetin 545.41
    span 80 604.52
    1,4-butanediol 397.74
    1,1-dichloroethane 1130.14
    2-methyl-1-pentanol 635.42
    methyl formate 646.87
    2-methyl-1-butanol 1013.56
    n-decane 248.79
    butyronitrile 927.07
    3,7-dimethyl-1-octanol 630.31
    1-chlorooctane 516.0
    1-chlorotetradecane 217.83
    n-nonane 293.16
    undecane 173.52
    tert-butylcyclohexane 330.38
    cyclooctane 407.31
    cyclopentanol 1382.81
    tetrahydropyran 2010.57
    tert-amyl methyl ether 1037.39
    2,5,8-trioxanonane 688.23
    1-hexene 1265.83
    2-isopropoxyethanol 552.51
    2,2,2-trifluoroethanol 650.22
    methyl butyrate 630.29

    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

Botanical

Name CAS Botanical Proportion
Osmanthus concentrate 1 (Sukhumi-Abkhasia) 68917-05-5 Osmanthus fragrans (Thunb.) Lour., fam. Oleaceae 0.4%