Acetic acid, 2-cyclopentylidene-, methyl ester

Overview IFRA Request a quote

  • Identifiers

    CAS number
    40203-73-4

    Molecular formula
    C8H12O2

    SMILES
    COC(=O)C=C1CCCC1

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Fruity 90.93%
    Sweet 73.99%
    Floral 66.09%
    Green 38.14%
    Pineapple 38.13%
    Honey 36.7%
    Berry 35.32%
    Rose 34.08%
    Plum 33.22%
    Waxy 32.88%

     

    Flavor
    Fruity 69.41%
    Berry 27.39%
    Floral 26.82%
    Fruit 24.66%
    Fatty 24.63%
    Sweet 24.55%
    Pineapple 24.24%
    Tropical 22.48%
    Spicy 21.58%
    Apple 19.73%

     

    Odor impact est.
    Medium

  • Properties

    XLogP3-AA
    1.6

    pKa est.
    7.77 (neutral)

    Molecular weight
    140.18 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Moderately fast

    Boiling point est.
    202°C

    Flash point

    • 81.21 ˚C est.

  • Synonyms

    • 40203-73-4
    • Methyl cyclopentylideneacetate
    • methyl 2-cyclopentylideneacetate
    • CYCLOPENTYLIDENEACETIC ACID METHYL ESTER
    • Acetic acid, 2-cyclopentylidene-, methyl ester
    • Cyclopentylideneacetic acid, methyl ester
    • Acetic acid, cyclopentylidene-, methyl ester
    • EINECS 254-837-3
    • Cyclopentylidene-acetic acid methyl ester
    • DTXSID2052077
    • EC 254-837-3
    • tuberose acetate
    • NBV7T69H2R
    • methyl2-cyclopentylideneacetate
    • SCHEMBL873013
    • DTXCID7030644
    • ZDBCSZOFHPULAS-UHFFFAOYSA-N
    • QBA20373
    • AKOS017417055
    • Cyclopentylidene acetic acid methyl ester
    • BS-28158
    • DB-307780
    • CS-0218025
    • NS00006677
    • EN300-97942
    • G58682
    • 254-837-3
    • Cyclopidene

  • Applications

    Acetic acid, 2-cyclopentylidene-, methyl ester (CAS 40203-73-4) is a synthetic building block used primarily in organic synthesis. Its α,β-unsaturated structure and exocyclic double bond make it a Michael-type acceptor, enabling conjugate additions and related transformations to access cyclopentyl-containing intermediates. In industry, it is commonly used as an intermediate for pharmaceutical development and as a precursor in the preparation of specialty polymers and crosslinkable resins. It can serve as a monomer or co-monomer in coatings, inks, and adhesive formulations where an unsaturated ester functionality is advantageous. It may also act as a precursor in agrochemical syntheses and other industrial chemicals, with use governed by local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 471.26
    methanol 527.93
    isopropanol 497.71
    water 2.74
    ethyl acetate 160.44
    n-propanol 428.91
    acetone 284.44
    n-butanol 391.46
    acetonitrile 278.64
    DMF 1021.38
    toluene 148.57
    isobutanol 344.42
    1,4-dioxane 429.66
    methyl acetate 225.5
    THF 455.55
    2-butanone 263.59
    n-pentanol 254.91
    sec-butanol 459.08
    n-hexane 23.3
    ethylene glycol 200.51
    NMP 441.89
    cyclohexane 48.8
    DMSO 514.57
    n-butyl acetate 156.01
    n-octanol 182.13
    chloroform 1099.8
    n-propyl acetate 115.78
    acetic acid 385.77
    dichloromethane 748.9
    cyclohexanone 361.81
    propylene glycol 335.68
    isopropyl acetate 103.16
    DMAc 498.5
    2-ethoxyethanol 285.09
    isopentanol 293.83
    n-heptane 22.63
    ethyl formate 208.32
    1,2-dichloroethane 348.05
    n-hexanol 277.87
    2-methoxyethanol 542.97
    isobutyl acetate 84.86
    tetrachloromethane 108.06
    n-pentyl acetate 109.18
    transcutol 535.05
    n-heptanol 156.77
    ethylbenzene 108.35
    MIBK 133.21
    2-propoxyethanol 355.03
    tert-butanol 470.38
    MTBE 183.72
    2-butoxyethanol 237.68
    propionic acid 353.91
    o-xylene 124.92
    formic acid 144.96
    diethyl ether 131.54
    m-xylene 121.86
    p-xylene 138.0
    chlorobenzene 232.01
    dimethyl carbonate 104.93
    n-octane 14.2
    formamide 196.74
    cyclopentanone 383.37
    2-pentanone 185.76
    anisole 207.23
    cyclopentyl methyl ether 177.76
    gamma-butyrolactone 406.2
    1-methoxy-2-propanol 425.05
    pyridine 434.78
    3-pentanone 131.36
    furfural 483.17
    n-dodecane 18.63
    diethylene glycol 333.12
    diisopropyl ether 45.77
    tert-amyl alcohol 358.93
    acetylacetone 189.57
    n-hexadecane 20.63
    acetophenone 193.67
    methyl propionate 168.76
    isopentyl acetate 151.05
    trichloroethylene 717.36
    n-nonanol 147.93
    cyclohexanol 325.66
    benzyl alcohol 220.87
    2-ethylhexanol 157.64
    isooctanol 125.67
    dipropyl ether 95.86
    1,2-dichlorobenzene 225.95
    ethyl lactate 132.32
    propylene carbonate 289.2
    n-methylformamide 384.8
    2-pentanol 259.44
    n-pentane 28.11
    1-propoxy-2-propanol 270.3
    1-methoxy-2-propyl acetate 169.69
    2-(2-methoxypropoxy) propanol 235.22
    mesitylene 81.5
    ε-caprolactone 292.52
    p-cymene 78.2
    epichlorohydrin 448.58
    1,1,1-trichloroethane 344.58
    2-aminoethanol 347.46
    morpholine-4-carbaldehyde 452.03
    sulfolane 492.72
    2,2,4-trimethylpentane 21.9
    2-methyltetrahydrofuran 284.53
    n-hexyl acetate 186.29
    isooctane 18.15
    2-(2-butoxyethoxy)ethanol 294.79
    sec-butyl acetate 85.54
    tert-butyl acetate 123.48
    decalin 31.55
    glycerin 355.89
    diglyme 435.0
    acrylic acid 328.06
    isopropyl myristate 84.28
    n-butyric acid 357.55
    acetyl acetate 111.75
    di(2-ethylhexyl) phthalate 105.14
    ethyl propionate 111.0
    nitromethane 432.24
    1,2-diethoxyethane 135.2
    benzonitrile 298.82
    trioctyl phosphate 78.36
    1-bromopropane 229.26
    gamma-valerolactone 475.8
    n-decanol 116.08
    triethyl phosphate 86.49
    4-methyl-2-pentanol 136.41
    propionitrile 295.2
    vinylene carbonate 306.64
    1,1,2-trichlorotrifluoroethane 465.3
    DMS 134.76
    cumene 82.03
    2-octanol 121.1
    2-hexanone 141.18
    octyl acetate 113.73
    limonene 105.76
    1,2-dimethoxyethane 349.86
    ethyl orthosilicate 77.9
    tributyl phosphate 77.67
    diacetone alcohol 223.08
    N,N-dimethylaniline 156.05
    acrylonitrile 405.54
    aniline 247.78
    1,3-propanediol 397.41
    bromobenzene 238.86
    dibromomethane 532.15
    1,1,2,2-tetrachloroethane 659.53
    2-methyl-cyclohexyl acetate 118.33
    tetrabutyl urea 115.06
    diisobutyl methanol 96.85
    2-phenylethanol 218.78
    styrene 133.75
    dioctyl adipate 125.09
    dimethyl sulfate 168.87
    ethyl butyrate 117.29
    methyl lactate 181.44
    butyl lactate 137.86
    diethyl carbonate 106.48
    propanediol butyl ether 293.72
    triethyl orthoformate 97.22
    p-tert-butyltoluene 77.3
    methyl 4-tert-butylbenzoate 209.19
    morpholine 502.37
    tert-butylamine 266.67
    n-dodecanol 93.68
    dimethoxymethane 272.15
    ethylene carbonate 226.83
    cyrene 216.42
    2-ethoxyethyl acetate 141.24
    2-ethylhexyl acetate 112.33
    1,2,4-trichlorobenzene 270.41
    4-methylpyridine 371.77
    dibutyl ether 99.98
    2,6-dimethyl-4-heptanol 96.85
    DEF 247.05
    dimethyl isosorbide 285.87
    tetrachloroethylene 366.69
    eugenol 222.54
    triacetin 172.95
    span 80 243.41
    1,4-butanediol 192.57
    1,1-dichloroethane 422.96
    2-methyl-1-pentanol 211.31
    methyl formate 273.24
    2-methyl-1-butanol 304.09
    n-decane 25.1
    butyronitrile 302.6
    3,7-dimethyl-1-octanol 157.22
    1-chlorooctane 93.54
    1-chlorotetradecane 47.26
    n-nonane 22.74
    undecane 21.34
    tert-butylcyclohexane 31.12
    cyclooctane 16.72
    cyclopentanol 362.72
    tetrahydropyran 341.16
    tert-amyl methyl ether 145.39
    2,5,8-trioxanonane 344.71
    1-hexene 95.39
    2-isopropoxyethanol 196.09
    2,2,2-trifluoroethanol 132.56
    methyl butyrate 168.05

    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