2,4-Dimethylthiophene

Overview IFRA Botanical Request a quote

  • Identifiers

    CAS number
    638-00-6

    Molecular formula
    C6H8S

    SMILES
    CC1=CC(=CS1)C

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

  • Odor profile

    Sulfurous 65.48%
    Roasted 59.73%
    Green 58.76%
    Meaty 51.59%
    Onion 49.68%
    Alliaceous 45.95%
    Burnt 43.99%
    Nutty 42.63%
    Coffee 40.83%
    Savory 36.83%

    Scent© AI

  • Properties

    XLogP3-AA
    2.4

    pKa est.
    7.12 (neutral)

    Molecular weight
    112.19 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Boiling point

    • 139.00 to 141.00 °C. @ 760.00 mm Hg

    Flash point est.
    21.79 ˚C

  • Synonyms

    • 2,4-Dimethylthiophene
    • 638-00-6
    • Thiophene, 2,4-dimethyl-
    • 2,4-dimethyl-thiophene
    • Q9B2TF3UVC
    • MFCD00130082
    • EINECS 211-312-3
    • UNII-Q9B2TF3UVC
    • DTXSID40213238
    • SCHEMBL40746
    • DTXCID40135729
    • GEO-01226
    • AKOS005255556
    • FD03141
    • AS-50030
    • SY060377
    • DB-054551
    • CS-0152847
    • NS00042108
    • EN300-111893
    • O10605
    • 211-312-3

  • Applications

    2,4-Dimethylthiophene (CAS 638-00-6) is an electron-rich heteroaromatic used chiefly as a synthetic building block for installing thienyl motifs in pharmaceuticals, agrochemicals, and functional materials; after halogenation or metalation it participates in C–C cross-couplings (Suzuki–Miyaura, Stille, Kumada, Negishi), formylation and oxidative transformations (to sulfoxides/sulfones) to access diverse derivatives; it also serves as a monomer/fragment for conjugated polythiophene-type materials to tune conductivity, hole transport, and absorption in organic electronics (OPV, OLED, OFET) and sensors; in addition, it is employed as a GC/GC‑MS reference standard, a probe molecule in catalysis and C–H activation studies on thiophene cores, and a model sulfur-aromatic in flavor/aroma research on volatile formation.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 797.9
    methanol 633.32
    isopropanol 569.44
    water 4.82
    ethyl acetate 1101.42
    n-propanol 626.73
    acetone 860.5
    n-butanol 714.66
    acetonitrile 655.35
    DMF 582.03
    toluene 835.12
    isobutanol 470.41
    1,4-dioxane 1705.64
    methyl acetate 836.88
    THF 1754.19
    2-butanone 888.1
    n-pentanol 577.34
    sec-butanol 626.34
    n-hexane 360.96
    ethylene glycol 140.96
    NMP 888.13
    cyclohexane 436.75
    DMSO 470.97
    n-butyl acetate 877.96
    n-octanol 442.43
    chloroform 1699.86
    n-propyl acetate 524.47
    acetic acid 554.38
    dichloromethane 1320.08
    cyclohexanone 1129.83
    propylene glycol 221.96
    isopropyl acetate 697.63
    DMAc 708.01
    2-ethoxyethanol 746.07
    isopentanol 584.32
    n-heptane 407.1
    ethyl formate 465.13
    1,2-dichloroethane 802.34
    n-hexanol 1028.48
    2-methoxyethanol 922.95
    isobutyl acetate 390.36
    tetrachloromethane 518.59
    n-pentyl acetate 497.61
    transcutol 1674.62
    n-heptanol 464.74
    ethylbenzene 330.34
    MIBK 567.67
    2-propoxyethanol 1321.06
    tert-butanol 709.31
    MTBE 977.97
    2-butoxyethanol 657.23
    propionic acid 445.46
    o-xylene 458.84
    formic acid 166.1
    diethyl ether 1432.2
    m-xylene 555.21
    p-xylene 367.6
    chlorobenzene 674.2
    dimethyl carbonate 294.72
    n-octane 133.97
    formamide 248.86
    cyclopentanone 991.06
    2-pentanone 905.32
    anisole 665.7
    cyclopentyl methyl ether 1186.94
    gamma-butyrolactone 889.15
    1-methoxy-2-propanol 814.65
    pyridine 985.75
    3-pentanone 719.56
    furfural 783.98
    n-dodecane 89.43
    diethylene glycol 670.98
    diisopropyl ether 534.79
    tert-amyl alcohol 688.26
    acetylacetone 791.99
    n-hexadecane 99.5
    acetophenone 458.16
    methyl propionate 679.43
    isopentyl acetate 711.2
    trichloroethylene 1301.86
    n-nonanol 404.84
    cyclohexanol 732.99
    benzyl alcohol 424.96
    2-ethylhexanol 662.39
    isooctanol 370.87
    dipropyl ether 977.85
    1,2-dichlorobenzene 549.23
    ethyl lactate 219.99
    propylene carbonate 553.44
    n-methylformamide 364.1
    2-pentanol 607.32
    n-pentane 346.08
    1-propoxy-2-propanol 994.57
    1-methoxy-2-propyl acetate 802.44
    2-(2-methoxypropoxy) propanol 525.5
    mesitylene 346.77
    ε-caprolactone 928.8
    p-cymene 300.06
    epichlorohydrin 1083.2
    1,1,1-trichloroethane 1097.37
    2-aminoethanol 301.47
    morpholine-4-carbaldehyde 1090.17
    sulfolane 712.18
    2,2,4-trimethylpentane 169.79
    2-methyltetrahydrofuran 1599.02
    n-hexyl acetate 673.41
    isooctane 144.92
    2-(2-butoxyethoxy)ethanol 745.36
    sec-butyl acetate 422.97
    tert-butyl acetate 740.23
    decalin 202.12
    glycerin 286.85
    diglyme 1170.3
    acrylic acid 339.52
    isopropyl myristate 303.39
    n-butyric acid 711.18
    acetyl acetate 627.34
    di(2-ethylhexyl) phthalate 230.23
    ethyl propionate 466.67
    nitromethane 716.05
    1,2-diethoxyethane 997.12
    benzonitrile 493.31
    trioctyl phosphate 181.77
    1-bromopropane 784.88
    gamma-valerolactone 1206.27
    n-decanol 305.2
    triethyl phosphate 243.99
    4-methyl-2-pentanol 375.2
    propionitrile 538.0
    vinylene carbonate 519.34
    1,1,2-trichlorotrifluoroethane 659.12
    DMS 380.85
    cumene 238.37
    2-octanol 321.73
    2-hexanone 604.49
    octyl acetate 376.41
    limonene 521.86
    1,2-dimethoxyethane 993.86
    ethyl orthosilicate 272.98
    tributyl phosphate 212.92
    diacetone alcohol 659.77
    N,N-dimethylaniline 436.83
    acrylonitrile 487.17
    aniline 706.57
    1,3-propanediol 441.58
    bromobenzene 713.86
    dibromomethane 1016.67
    1,1,2,2-tetrachloroethane 999.62
    2-methyl-cyclohexyl acetate 470.73
    tetrabutyl urea 257.3
    diisobutyl methanol 344.53
    2-phenylethanol 628.67
    styrene 420.98
    dioctyl adipate 317.0
    dimethyl sulfate 335.48
    ethyl butyrate 578.65
    methyl lactate 284.45
    butyl lactate 293.75
    diethyl carbonate 324.22
    propanediol butyl ether 434.93
    triethyl orthoformate 434.3
    p-tert-butyltoluene 306.46
    methyl 4-tert-butylbenzoate 435.54
    morpholine 1596.16
    tert-butylamine 559.38
    n-dodecanol 243.03
    dimethoxymethane 755.63
    ethylene carbonate 488.92
    cyrene 440.01
    2-ethoxyethyl acetate 647.76
    2-ethylhexyl acetate 617.26
    1,2,4-trichlorobenzene 623.83
    4-methylpyridine 1042.95
    dibutyl ether 583.8
    2,6-dimethyl-4-heptanol 344.53
    DEF 874.08
    dimethyl isosorbide 799.0
    tetrachloroethylene 720.69
    eugenol 419.35
    triacetin 466.31
    span 80 508.13
    1,4-butanediol 225.29
    1,1-dichloroethane 1055.57
    2-methyl-1-pentanol 536.24
    methyl formate 280.88
    2-methyl-1-butanol 592.84
    n-decane 147.61
    butyronitrile 677.74
    3,7-dimethyl-1-octanol 449.96
    1-chlorooctane 384.55
    1-chlorotetradecane 172.53
    n-nonane 155.64
    undecane 110.17
    tert-butylcyclohexane 199.9
    cyclooctane 221.31
    cyclopentanol 626.75
    tetrahydropyran 1547.84
    tert-amyl methyl ether 852.67
    2,5,8-trioxanonane 810.5
    1-hexene 617.44
    2-isopropoxyethanol 622.17
    2,2,2-trifluoroethanol 247.6
    methyl butyrate 501.84

    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
Onion 8002-72-0 Allium cepa L., fam. Liliaceae 0.1%
Onion (shallot) 8002-72-0 Allium cepa L., Aggregatum g., fam. Liliaceae 0.2%
Onion, welsh 8002-72-0 Allium fistulosum L. var. Maichuon, fam. Liliaceae 1.85%
Scallion Allium fistulosum L. var. Caespitosum, fam. Liliaceae 0.07%
Scallion (Cuba) Allium fistulosum L., fam. Liliaceae 0.4%