2,5-Dimethylthiophene

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  • Identifiers

    CAS number
    638-02-8

    Molecular formula
    C6H8S

    SMILES
    CC1=CC=C(S1)C

    Safety labels

    Flammable
    Flammable

    Retention indicies (RI)

    • Carbowax: 1161.0

  • Odor profile

    Green 72.58%
    Sulfurous 69.16%
    Roasted 53.34%
    Alliaceous 51.59%
    Onion 51.15%
    Nutty 50.81%
    Meaty 50.65%
    Burnt 48.09%
    Vegetable 43.19%
    Fresh 41.69%

    Scent© AI

  • Properties

    XLogP3-AA
    2.4

    pKa est.
    8.03 (weak base)

    Molecular weight
    112.19 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Melting point expt.

    • -62.6 °C

    Boiling point

    • 135.00 °C. @ 760.00 mm Hg

    Flash point est.
    15.9 ˚C

  • Synonyms

    • 2,5-DIMETHYLTHIOPHENE
    • 638-02-8
    • Thiophene, 2,5-dimethyl-
    • 2,5-dimethyl-thiophene
    • UNII-V6DDX6WB12
    • V6DDX6WB12
    • MFCD00005452
    • EINECS 211-313-9
    • NSC-60689
    • DTXSID2074295
    • NSC 60689
    • NSC60689
    • 2,5 Dimethylthiophene
    • Thiophene,5-dimethyl-
    • 2,5-dimethyl thiophene
    • Thiophene, 2,5dimethyl
    • SCHEMBL64283
    • 2 pound not5-Dimethylthiophene
    • DTXCID0044103
    • 2,5-Dimethylthiophene, >=98%
    • 2,5-Dimethylthiophene, 98.5%
    • CHEBI:167073
    • AKOS000121512
    • AKOS016017809
    • PS-3263
    • AC-18077
    • SY018010
    • 2,5-Dimethylthiophene, analytical standard
    • DB-054553
    • CS-0022382
    • D1591
    • NS00022605
    • EN300-21089
    • F11266
    • 2,5-Dimethylthiophene, purum, >=98.0% (GC)
    • Q27291590
    • F0001-1465
    • 211-313-9

  • Applications

    2,5-Dimethylthiophene (CAS 638-02-8) is a sulfur-containing aromatic heterocycle used as an intermediate in organic and pharmaceutical synthesis, a building block for conjugated polymers and organic electronic materials (e.g., conducting polythiophene derivatives), a handle to access sulfoxide/sulfone motifs in medicinal chemistry, an analytical/aroma reference standard for gas chromatography and flavor research, a trace flavor ingredient to impart roasted, smoky, meaty, and nutty notes in foods and beverages (subject to flavor safety regulations), a model compound in studies of fuel hydrodesulfurization catalysis and adsorption of sulfur VOCs, and a precursor for 3,4-halogenation/functionalization to construct more complex heterocycles; in materials chemistry it is valued for aromatic stability and cross-coupling compatibility enabling design of conjugated systems for sensors, OLEDs, and optoelectronics, while practical use emphasizes odor control, industrial hygiene, and proper handling of sulfur-containing waste.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 253.82
    methanol 209.11
    isopropanol 208.09
    water 2.46
    ethyl acetate 537.77
    n-propanol 236.24
    acetone 412.06
    n-butanol 266.84
    acetonitrile 305.71
    DMF 352.79
    toluene 435.54
    isobutanol 187.66
    1,4-dioxane 746.37
    methyl acetate 434.49
    THF 905.42
    2-butanone 437.19
    n-pentanol 211.87
    sec-butanol 245.39
    n-hexane 155.59
    ethylene glycol 52.76
    NMP 552.89
    cyclohexane 196.01
    DMSO 249.15
    n-butyl acetate 450.17
    n-octanol 192.75
    chloroform 1182.68
    n-propyl acetate 298.96
    acetic acid 257.46
    dichloromethane 885.11
    cyclohexanone 586.41
    propylene glycol 85.04
    isopropyl acetate 364.33
    DMAc 426.14
    2-ethoxyethanol 320.46
    isopentanol 225.42
    n-heptane 183.75
    ethyl formate 258.07
    1,2-dichloroethane 508.43
    n-hexanol 374.93
    2-methoxyethanol 402.57
    isobutyl acetate 221.41
    tetrachloromethane 358.58
    n-pentyl acetate 282.98
    transcutol 717.89
    n-heptanol 211.51
    ethylbenzene 211.85
    MIBK 292.8
    2-propoxyethanol 547.79
    tert-butanol 288.87
    MTBE 444.22
    2-butoxyethanol 319.58
    propionic acid 226.25
    o-xylene 272.45
    formic acid 79.56
    diethyl ether 574.62
    m-xylene 311.08
    p-xylene 244.44
    chlorobenzene 445.71
    dimethyl carbonate 178.92
    n-octane 73.92
    formamide 135.0
    cyclopentanone 616.22
    2-pentanone 432.67
    anisole 401.0
    cyclopentyl methyl ether 593.89
    gamma-butyrolactone 584.23
    1-methoxy-2-propanol 353.34
    pyridine 544.61
    3-pentanone 372.03
    furfural 533.91
    n-dodecane 49.29
    diethylene glycol 269.72
    diisopropyl ether 258.03
    tert-amyl alcohol 295.41
    acetylacetone 429.5
    n-hexadecane 55.97
    acetophenone 301.89
    methyl propionate 356.03
    isopentyl acetate 379.87
    trichloroethylene 900.37
    n-nonanol 190.28
    cyclohexanol 302.27
    benzyl alcohol 233.94
    2-ethylhexanol 294.84
    isooctanol 181.24
    dipropyl ether 464.27
    1,2-dichlorobenzene 410.82
    ethyl lactate 137.2
    propylene carbonate 367.98
    n-methylformamide 199.34
    2-pentanol 247.33
    n-pentane 141.36
    1-propoxy-2-propanol 433.53
    1-methoxy-2-propyl acetate 434.71
    2-(2-methoxypropoxy) propanol 270.09
    mesitylene 213.69
    ε-caprolactone 513.71
    p-cymene 195.82
    epichlorohydrin 644.87
    1,1,1-trichloroethane 778.02
    2-aminoethanol 114.4
    morpholine-4-carbaldehyde 605.88
    sulfolane 485.11
    2,2,4-trimethylpentane 89.5
    2-methyltetrahydrofuran 759.85
    n-hexyl acetate 356.43
    isooctane 71.13
    2-(2-butoxyethoxy)ethanol 346.62
    sec-butyl acetate 251.01
    tert-butyl acetate 415.34
    decalin 116.37
    glycerin 116.37
    diglyme 612.19
    acrylic acid 187.42
    isopropyl myristate 183.21
    n-butyric acid 351.63
    acetyl acetate 369.34
    di(2-ethylhexyl) phthalate 139.35
    ethyl propionate 288.67
    nitromethane 423.41
    1,2-diethoxyethane 464.47
    benzonitrile 292.12
    trioctyl phosphate 106.93
    1-bromopropane 453.46
    gamma-valerolactone 677.96
    n-decanol 149.1
    triethyl phosphate 180.16
    4-methyl-2-pentanol 168.52
    propionitrile 272.95
    vinylene carbonate 354.06
    1,1,2-trichlorotrifluoroethane 439.97
    DMS 251.09
    cumene 158.03
    2-octanol 148.83
    2-hexanone 311.92
    octyl acetate 217.72
    limonene 298.86
    1,2-dimethoxyethane 490.57
    ethyl orthosilicate 187.9
    tributyl phosphate 128.69
    diacetone alcohol 348.87
    N,N-dimethylaniline 276.31
    acrylonitrile 268.17
    aniline 364.66
    1,3-propanediol 169.52
    bromobenzene 488.63
    dibromomethane 656.41
    1,1,2,2-tetrachloroethane 702.23
    2-methyl-cyclohexyl acetate 294.13
    tetrabutyl urea 153.6
    diisobutyl methanol 180.54
    2-phenylethanol 334.52
    styrene 253.78
    dioctyl adipate 204.12
    dimethyl sulfate 243.4
    ethyl butyrate 349.35
    methyl lactate 163.43
    butyl lactate 168.89
    diethyl carbonate 228.59
    propanediol butyl ether 191.36
    triethyl orthoformate 280.65
    p-tert-butyltoluene 207.29
    methyl 4-tert-butylbenzoate 308.68
    morpholine 691.44
    tert-butylamine 223.18
    n-dodecanol 121.41
    dimethoxymethane 405.43
    ethylene carbonate 312.8
    cyrene 279.19
    2-ethoxyethyl acetate 368.33
    2-ethylhexyl acetate 346.59
    1,2,4-trichlorobenzene 446.95
    4-methylpyridine 562.16
    dibutyl ether 292.08
    2,6-dimethyl-4-heptanol 180.54
    DEF 427.17
    dimethyl isosorbide 488.79
    tetrachloroethylene 501.79
    eugenol 261.19
    triacetin 301.37
    span 80 268.33
    1,4-butanediol 85.33
    1,1-dichloroethane 660.01
    2-methyl-1-pentanol 216.08
    methyl formate 166.97
    2-methyl-1-butanol 243.46
    n-decane 82.38
    butyronitrile 323.8
    3,7-dimethyl-1-octanol 212.03
    1-chlorooctane 204.89
    1-chlorotetradecane 100.35
    n-nonane 84.75
    undecane 61.34
    tert-butylcyclohexane 113.93
    cyclooctane 111.58
    cyclopentanol 295.89
    tetrahydropyran 683.39
    tert-amyl methyl ether 414.12
    2,5,8-trioxanonane 443.25
    1-hexene 271.37
    2-isopropoxyethanol 272.72
    2,2,2-trifluoroethanol 155.97
    methyl butyrate 309.58

    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 (shallot) 8002-72-0 Allium cepa L., Aggregatum g., fam. Liliaceae 0.05%
Onion, welsh 8002-72-0 Allium fistulosum L. var. Maichuon, fam. Liliaceae 0.1%
Scallion Allium fistulosum L. var. Caespitosum, fam. Liliaceae 0.06%