2,6,6-Trimethylcyclohex-2-ene-1,4-dione

Overview IFRA Botanical Request a quote

  • Identifiers

    CAS number
    1125-21-9

    Molecular formula
    C9H12O2

    SMILES
    CC1=CC(=O)CC(C1=O)(C)C

    Safety labels

    Irritant
    Irritant

    Retention indicies (RI)

    • DB5: 1142.0
    • Carbowax: 1655.0

  • Odor profile

    Sweet 82.05%
    Tobacco 58.13%
    Caramellic 56.34%
    Woody 52.85%
    Mint 52.38%
    Camphoreous 45.92%
    Tea 44.15%
    Hay 42.73%
    Burnt 39.75%
    Honey 39.25%

    Scent© AI

  • Properties

    XLogP3-AA
    1.0

    Molecular weight
    152.19 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Slow

    Melting point expt.

    • 21 °C

    Boiling point

    • 92.00 to 94.00 °C. @ 11.00 mm Hg

    Flash point est.
    84.13 ˚C

    Solubility expt.

    • slightly
    • Slightly soluble in water
    • Soluble (in ethanol)

  • Synonyms

    • 1125-21-9
    • Ketoisophorone
    • 2,6,6-Trimethyl-2-cyclohexene-1,4-dione
    • 4-Oxoisophorone
    • 2,6,6-Trimethylcyclohex-2-ene-1,4-dione
    • 4-Ketoisophorone
    • Oxopholone
    • keto-Isophorone
    • Oxophorone
    • 2-CYCLOHEXENE-1,4-DIONE, 2,6,6-TRIMETHYL-
    • 6-Oxoisophorone
    • 4-Oxo-alpha-isophorone
    • FEMA No. 3421
    • Oxoisophorone
    • UNII-72WY3KLB5R
    • 3,5,5-Trimethyl-2-cyclohexene-1,4-dione
    • EINECS 214-406-2
    • 72WY3KLB5R
    • DTXSID9021685
    • 2,6,6-Trimethyl-2-cyclohexen-1,4-dione
    • MFCD00043119
    • DTXCID701685
    • FEMA 3421
    • EC 214-406-2
    • 2,2,6-trimethylcyclohex-2-en-1,4-dione
    • 3,5,5-Trimethylcyclohex-2-en-1,4-dione
    • 3,5,5-trimethylcyclohex-2-ene-1,4-dione
    • 2-Cyclohexen-1,4-dione, 2,6,6-trimethyl
    • 2-cyclohexene-1,4-dione, 2,6,6-trimethyl
    • 2,2,6-Trimethyl-2-cyclohexene-1,4-dione (cetoisophorone)
    • 2,6,6-TRIMETHYLCYCLOHEX-2-ENE-1,4-DIONE [FHFI]
    • 2,2,6-Trimethylcyclohex-2-en-1,4-dione (4-oxo-isophorone)
    • 2,6,6-Trimethy-2-cyclohexene-1,4-dione (4-oxoisophorone)
    • OIP cpd
    • TMEC-E-D
    • 4-Oxo-.alpha.-isophorone
    • SCHEMBL444616
    • 4-Oxoisophorone, >=98%, FG
    • CHEBI:179251
    • Tox21_201193
    • BBL027987
    • s3991
    • STK801843
    • AKOS005622552
    • CCG-266233
    • NCGC00248952-01
    • NCGC00258745-01
    • AS-14431
    • SY049954
    • 2,6,6-trimethylcyclohex-2-en-1,4-dione
    • 2,6,6-trimethylcyclohex-2-ene-1,4-dion
    • CAS-1125-21-9
    • DB-003240
    • HY-107832
    • 2,2,6-Trimethyl-cyclohex-5-en-1,4-dione
    • 2,6,6-trimethyl-cyclohex-2-ene-1,4-dione
    • 3,5,5-trimethyl-cyclohex-2-en-1,4-dione
    • CS-0030708
    • K0034
    • NS00010663
    • EN300-198525
    • F12784
    • 2,6,6-Trimethyl-2-cyclohexene-1,4-dione, 98%
    • Q1490748
    • Z1255438584
    • 2,6,6-Trimethyl-2-cyclohexene-1,4-dione, analytical standard
    • 214-406-2

  • Applications

    4-Oxoisophorone (CAS 1125-21-9) is a cyclic diketone with a mild fruity-woody odor that serves as a highly reactive synthetic intermediate thanks to its Michael-acceptor character and its facility for conversion into ionone derivatives; it is a key building block in the industrial manufacture of carotenoids such as canthaxanthin, astaxanthin and β-ionone as well as vitamins E and A, shortening synthetic routes and boosting yields, while fragrance formulators use it to impart warm woody, tobacco-leaf and red-fruit nuances in perfumes, cosmetics and food flavors; in pharmaceuticals the 1,4-dione scaffold is explored for antibacterial, anti-inflammatory and antioxidant agents and as a drug-delivery moiety, and the polymer sector employs it as a photoinitiator and UV-absorbing module to improve colorfastness of engineering plastics; 4-Oxoisophorone is also widely used in organic laboratories as an analytical standard, a model compound for enone-dione mechanisms, and a versatile core for the synthesis and surface modification of next-generation organic nanomaterials.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 584.7
    methanol 978.63
    isopropanol 388.19
    water 16.09
    ethyl acetate 555.45
    n-propanol 417.35
    acetone 661.66
    n-butanol 383.83
    acetonitrile 873.48
    DMF 894.77
    toluene 375.44
    isobutanol 307.84
    1,4-dioxane 890.41
    methyl acetate 537.84
    THF 1301.12
    2-butanone 482.77
    n-pentanol 264.7
    sec-butanol 321.06
    n-hexane 114.89
    ethylene glycol 146.18
    NMP 815.91
    cyclohexane 116.42
    DMSO 451.79
    n-butyl acetate 335.81
    n-octanol 178.53
    chloroform 1248.68
    n-propyl acetate 294.72
    acetic acid 806.43
    dichloromethane 1123.62
    cyclohexanone 681.75
    propylene glycol 127.05
    isopropyl acetate 348.01
    DMAc 522.78
    2-ethoxyethanol 395.38
    isopentanol 314.02
    n-heptane 63.71
    ethyl formate 437.36
    1,2-dichloroethane 608.31
    n-hexanol 389.09
    2-methoxyethanol 725.78
    isobutyl acetate 187.75
    tetrachloromethane 283.95
    n-pentyl acetate 214.78
    transcutol 821.97
    n-heptanol 164.37
    ethylbenzene 197.21
    MIBK 318.92
    2-propoxyethanol 582.26
    tert-butanol 434.49
    MTBE 382.2
    2-butoxyethanol 253.72
    propionic acid 422.43
    o-xylene 222.18
    formic acid 486.41
    diethyl ether 578.7
    m-xylene 299.88
    p-xylene 244.82
    chlorobenzene 382.87
    dimethyl carbonate 244.7
    n-octane 25.37
    formamide 485.75
    cyclopentanone 842.54
    2-pentanone 479.44
    anisole 353.3
    cyclopentyl methyl ether 647.75
    gamma-butyrolactone 1055.7
    1-methoxy-2-propanol 505.43
    pyridine 561.97
    3-pentanone 370.96
    furfural 773.6
    n-dodecane 19.2
    diethylene glycol 416.85
    diisopropyl ether 202.72
    tert-amyl alcohol 349.25
    acetylacetone 495.49
    n-hexadecane 22.09
    acetophenone 292.81
    methyl propionate 418.49
    isopentyl acetate 283.01
    trichloroethylene 1115.85
    n-nonanol 145.89
    cyclohexanol 387.59
    benzyl alcohol 243.61
    2-ethylhexanol 193.11
    isooctanol 125.53
    dipropyl ether 250.85
    1,2-dichlorobenzene 359.0
    ethyl lactate 144.93
    propylene carbonate 514.74
    n-methylformamide 613.89
    2-pentanol 276.23
    n-pentane 102.44
    1-propoxy-2-propanol 327.2
    1-methoxy-2-propyl acetate 335.21
    2-(2-methoxypropoxy) propanol 206.46
    mesitylene 186.64
    ε-caprolactone 565.25
    p-cymene 113.79
    epichlorohydrin 1008.09
    1,1,1-trichloroethane 697.3
    2-aminoethanol 241.26
    morpholine-4-carbaldehyde 748.65
    sulfolane 782.27
    2,2,4-trimethylpentane 44.09
    2-methyltetrahydrofuran 827.11
    n-hexyl acetate 334.44
    isooctane 40.05
    2-(2-butoxyethoxy)ethanol 280.95
    sec-butyl acetate 210.88
    tert-butyl acetate 370.64
    decalin 64.65
    glycerin 200.66
    diglyme 526.46
    acrylic acid 406.23
    isopropyl myristate 116.97
    n-butyric acid 517.49
    acetyl acetate 388.01
    di(2-ethylhexyl) phthalate 101.79
    ethyl propionate 283.25
    nitromethane 1146.69
    1,2-diethoxyethane 333.88
    benzonitrile 379.02
    trioctyl phosphate 83.88
    1-bromopropane 431.34
    gamma-valerolactone 910.4
    n-decanol 102.93
    triethyl phosphate 120.26
    4-methyl-2-pentanol 173.74
    propionitrile 503.36
    vinylene carbonate 503.33
    1,1,2-trichlorotrifluoroethane 488.2
    DMS 288.35
    cumene 137.27
    2-octanol 122.58
    2-hexanone 287.71
    octyl acetate 142.38
    limonene 151.79
    1,2-dimethoxyethane 623.7
    ethyl orthosilicate 121.44
    tributyl phosphate 108.95
    diacetone alcohol 340.05
    N,N-dimethylaniline 235.4
    acrylonitrile 590.14
    aniline 325.0
    1,3-propanediol 352.96
    bromobenzene 375.04
    dibromomethane 755.68
    1,1,2,2-tetrachloroethane 773.55
    2-methyl-cyclohexyl acetate 190.49
    tetrabutyl urea 127.0
    diisobutyl methanol 109.74
    2-phenylethanol 275.55
    styrene 213.95
    dioctyl adipate 138.13
    dimethyl sulfate 323.37
    ethyl butyrate 237.62
    methyl lactate 191.64
    butyl lactate 152.42
    diethyl carbonate 169.73
    propanediol butyl ether 203.97
    triethyl orthoformate 160.23
    p-tert-butyltoluene 119.01
    methyl 4-tert-butylbenzoate 230.71
    morpholine 875.69
    tert-butylamine 290.64
    n-dodecanol 77.58
    dimethoxymethane 701.53
    ethylene carbonate 415.03
    cyrene 228.55
    2-ethoxyethyl acetate 287.72
    2-ethylhexyl acetate 221.71
    1,2,4-trichlorobenzene 384.71
    4-methylpyridine 615.94
    dibutyl ether 188.27
    2,6-dimethyl-4-heptanol 109.74
    DEF 480.17
    dimethyl isosorbide 380.78
    tetrachloroethylene 584.52
    eugenol 216.24
    triacetin 234.01
    span 80 171.65
    1,4-butanediol 146.28
    1,1-dichloroethane 702.11
    2-methyl-1-pentanol 234.17
    methyl formate 602.34
    2-methyl-1-butanol 298.55
    n-decane 34.93
    butyronitrile 511.28
    3,7-dimethyl-1-octanol 154.0
    1-chlorooctane 128.04
    1-chlorotetradecane 51.16
    n-nonane 34.91
    undecane 24.92
    tert-butylcyclohexane 59.27
    cyclooctane 52.69
    cyclopentanol 406.49
    tetrahydropyran 760.9
    tert-amyl methyl ether 313.99
    2,5,8-trioxanonane 323.8
    1-hexene 253.9
    2-isopropoxyethanol 274.36
    2,2,2-trifluoroethanol 336.36
    methyl butyrate 337.57

    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
Saffron 1 8022-19-3 Crocus sativus L., fam. Iridaceae 1.1%
Artemisia judaica (Israel) 2 Artemisia judaica L. (Bat'aran), fam. Asteraceae (Compositae) 0.6%
Saffron 2 8022-19-3 Crocus sativus L., fam. Iridaceae 4.1%
Carob bean powder 2a raw 9000-40-2 Ceratonia siliqua L., fam. Leguminoseae 0.01%