2,5-Norbornadiene

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  • Identifiers

    CAS number
    121-46-0

    Molecular formula
    C7H8

    SMILES
    C1C2C=CC1C=C2

    Safety labels

    Flammable
    Flammable

    Corrosive
    Corrosive

  • Odor profile

    Fragrance
    Green 48.02%
    Fruity 42.09%
    Sweet 36.58%
    Spicy 32.48%
    Herbal 30.37%
    Fresh 28.1%
    Woody 27.3%
    Citrus 26.57%
    Earthy 22.93%
    Oily 22.15%

     

    Flavor
    Animal 26.7%
    Bitter 22.41%
    Shrimp 21.04%
    Alkaline 20.54%
    Ammoniacal 19.58%
    Terpentine 18.23%
    Rotten 18.18%
    Tar 18.12%
    Tarry 17.95%
    Moth ball 17.91%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    2.1

    pKa est.
    8.58 (weak base)

    Molecular weight
    92.14 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Boiling point est.
    93°C

    Flash point

    • -10.29 ˚C est.
    • -6 °F (NFPA, 2010)

  • Synonyms

    • 2,5-Norbornadiene
    • Bicyclo[2.2.1]hepta-2,5-diene
    • 121-46-0
    • Norbornadiene
    • BICYCLO(2.2.1)HEPTA-2,5-DIENE
    • NSC 13672
    • UN2251
    • UNII-W9ZTQ75ZUS
    • 2,5-Norbornadiene (stabilized with BHT)
    • W9ZTQ75ZUS
    • Bicyclo(2.2.1)heptadiene
    • EINECS 204-472-0
    • AI3-24887
    • NSC-13672
    • NORBORNADIENE [MI]
    • DTXSID1059523
    • 3,6-Methano-1,4-cyclohexadiene
    • Bicyclo[2.2.1]-2,5-heptadiene
    • MFCD00082301
    • 16422-76-7
    • UN-2251
    • Bicyclo[2.2.1]heptadiene
    • NBD
    • Bicyclo(2.2.1)-2,5-heptadiene
    • Dicycloheptadiene
    • 8,9,10-Trinorborna-2,5-diene
    • BICYCLO(2.2.1)HEPTA-2,5-DIENE, STABILIZED
    • BICYCLO[2.2.1]HEPTA-2,5-DIENE, STABILIZED
    • 2,5Norbornadiene, inhibited
    • 3,6Methano1,4cyclohexadiene
    • 8,9,10Trinorborna2,5diene
    • Bicyclohepta2,5diene, inhibited
    • Bicyclo(2.2.1)hepta2,5diene
    • DTXCID6033669
    • NSC13672
    • NSC167540
    • STL453640
    • 2,5-NORBORNADIENE, STABILIZED
    • AKOS005145646
    • AKOS015912918
    • AKOS016008675
    • bicyclo-(2,2,1)-hepta-2,5-diene
    • NSC-167540
    • Bicyclo[2.2.1]hepta-2,5-diene, 98%
    • 2,5-Norbornadiene, (stabilized with BHT)
    • DB-243109
    • N0346
    • NS00023960
    • Bicyclo[2.2.1]hepta-2, dimer, stereoisomer
    • EN300-93414
    • bicyclo[2.2.1]hepta-2,5-diene,(Norbornadiene)
    • Q726795
    • Bicyclo(2,2,1)hepta-2,5-diene, inhibited or 2,5-Norborandiene, inhibited
    • 3,6-Methano-1,4-cyclohexadiene; Bicyclo[2.2.1]heptadiene; NSC 13672; Norbornadiene;
    • 204-472-0
    • Bicyclo(2,2,1)hepta-2,5-diene, inhibited or 2,5-Norborandiene, inhibited [UN2251] [Flammable liquid]

  • Applications

    2,5-Norbornadiene (CAS 121-46-0) is a reactive diene commonly used as a building block in organic synthesis, enabling Diels–Alder cycloadditions to access bicyclic and polycyclic frameworks that underpin pharmaceutical, agrochemical, and materials research. It is employed as a precursor or dienic component in the preparation of norbornene-based polymers and crosslinked networks in polymer science. The compound has been studied for molecular solar thermal energy storage (MOST) applications because it can photoisomerize to quadricyclane, allowing storage and controlled release of solar energy. In practical terms, it functions as a laboratory reagent and synthetic intermediate, supporting process development and route exploration in research settings, with use subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 161.67
    methanol 125.1
    isopropanol 124.11
    water 0.9
    ethyl acetate 336.19
    n-propanol 165.24
    acetone 180.13
    n-butanol 154.68
    acetonitrile 210.02
    DMF 146.43
    toluene 170.28
    isobutanol 105.29
    1,4-dioxane 379.96
    methyl acetate 251.15
    THF 375.72
    2-butanone 233.84
    n-pentanol 121.37
    sec-butanol 142.73
    n-hexane 68.58
    ethylene glycol 62.06
    NMP 137.52
    cyclohexane 62.64
    DMSO 161.43
    n-butyl acetate 213.32
    n-octanol 90.67
    chloroform 594.72
    n-propyl acetate 150.71
    acetic acid 140.65
    dichloromethane 406.79
    cyclohexanone 182.91
    propylene glycol 106.44
    isopropyl acetate 197.04
    DMAc 200.06
    2-ethoxyethanol 198.21
    isopentanol 125.27
    n-heptane 77.17
    ethyl formate 105.01
    1,2-dichloroethane 232.61
    n-hexanol 178.83
    2-methoxyethanol 248.3
    isobutyl acetate 105.12
    tetrachloromethane 122.58
    n-pentyl acetate 101.44
    transcutol 719.25
    n-heptanol 91.47
    ethylbenzene 89.79
    MIBK 140.46
    2-propoxyethanol 312.31
    tert-butanol 139.6
    MTBE 204.45
    2-butoxyethanol 160.48
    propionic acid 160.91
    o-xylene 104.79
    formic acid 45.15
    diethyl ether 291.45
    m-xylene 122.53
    p-xylene 95.7
    chlorobenzene 155.41
    dimethyl carbonate 106.07
    n-octane 27.41
    formamide 70.89
    cyclopentanone 222.17
    2-pentanone 203.04
    anisole 194.66
    cyclopentyl methyl ether 213.6
    gamma-butyrolactone 222.87
    1-methoxy-2-propanol 246.12
    pyridine 313.17
    3-pentanone 199.2
    furfural 201.42
    n-dodecane 20.61
    diethylene glycol 229.26
    diisopropyl ether 125.96
    tert-amyl alcohol 136.49
    acetylacetone 213.33
    n-hexadecane 22.26
    acetophenone 145.76
    methyl propionate 229.9
    isopentyl acetate 162.75
    trichloroethylene 429.95
    n-nonanol 87.99
    cyclohexanol 110.17
    benzyl alcohol 122.58
    2-ethylhexanol 129.33
    isooctanol 74.54
    dipropyl ether 246.8
    1,2-dichlorobenzene 137.79
    ethyl lactate 87.19
    propylene carbonate 156.76
    n-methylformamide 97.72
    2-pentanol 127.95
    n-pentane 61.53
    1-propoxy-2-propanol 268.28
    1-methoxy-2-propyl acetate 247.48
    2-(2-methoxypropoxy) propanol 184.01
    mesitylene 77.47
    ε-caprolactone 190.02
    p-cymene 80.48
    epichlorohydrin 291.38
    1,1,1-trichloroethane 281.13
    2-aminoethanol 116.43
    morpholine-4-carbaldehyde 239.87
    sulfolane 177.74
    2,2,4-trimethylpentane 37.76
    2-methyltetrahydrofuran 265.53
    n-hexyl acetate 136.21
    isooctane 33.67
    2-(2-butoxyethoxy)ethanol 238.22
    sec-butyl acetate 130.17
    tert-butyl acetate 182.94
    decalin 45.55
    glycerin 125.96
    diglyme 390.04
    acrylic acid 134.33
    isopropyl myristate 75.57
    n-butyric acid 193.69
    acetyl acetate 209.78
    di(2-ethylhexyl) phthalate 66.7
    ethyl propionate 171.13
    nitromethane 202.96
    1,2-diethoxyethane 295.32
    benzonitrile 130.83
    trioctyl phosphate 43.92
    1-bromopropane 215.95
    gamma-valerolactone 253.36
    n-decanol 69.43
    triethyl phosphate 80.66
    4-methyl-2-pentanol 92.93
    propionitrile 187.54
    vinylene carbonate 144.31
    1,1,2-trichlorotrifluoroethane 233.69
    DMS 142.81
    cumene 70.37
    2-octanol 59.04
    2-hexanone 146.43
    octyl acetate 89.52
    limonene 106.31
    1,2-dimethoxyethane 239.44
    ethyl orthosilicate 86.11
    tributyl phosphate 54.38
    diacetone alcohol 168.99
    N,N-dimethylaniline 121.12
    acrylonitrile 200.62
    aniline 179.45
    1,3-propanediol 131.04
    bromobenzene 174.38
    dibromomethane 311.99
    1,1,2,2-tetrachloroethane 347.14
    2-methyl-cyclohexyl acetate 121.99
    tetrabutyl urea 64.65
    diisobutyl methanol 89.66
    2-phenylethanol 142.49
    styrene 114.82
    dioctyl adipate 99.62
    dimethyl sulfate 113.05
    ethyl butyrate 180.4
    methyl lactate 120.36
    butyl lactate 84.37
    diethyl carbonate 122.02
    propanediol butyl ether 134.37
    triethyl orthoformate 135.64
    p-tert-butyltoluene 79.72
    methyl 4-tert-butylbenzoate 125.55
    morpholine 353.52
    tert-butylamine 112.32
    n-dodecanol 58.53
    dimethoxymethane 196.12
    ethylene carbonate 127.33
    cyrene 119.7
    2-ethoxyethyl acetate 186.99
    2-ethylhexyl acetate 141.95
    1,2,4-trichlorobenzene 177.49
    4-methylpyridine 212.72
    dibutyl ether 142.73
    2,6-dimethyl-4-heptanol 89.66
    DEF 188.84
    dimethyl isosorbide 229.53
    tetrachloroethylene 239.27
    eugenol 119.02
    triacetin 170.71
    span 80 150.99
    1,4-butanediol 67.04
    1,1-dichloroethane 265.0
    2-methyl-1-pentanol 107.71
    methyl formate 67.93
    2-methyl-1-butanol 125.43
    n-decane 31.43
    butyronitrile 162.15
    3,7-dimethyl-1-octanol 100.11
    1-chlorooctane 76.33
    1-chlorotetradecane 41.79
    n-nonane 32.02
    undecane 24.31
    tert-butylcyclohexane 43.5
    cyclooctane 40.1
    cyclopentanol 106.27
    tetrahydropyran 289.68
    tert-amyl methyl ether 174.51
    2,5,8-trioxanonane 274.4
    1-hexene 134.88
    2-isopropoxyethanol 163.23
    2,2,2-trifluoroethanol 71.59
    methyl butyrate 152.12

    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