5,6-Dihydroxyindole

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  • Identifiers

    CAS number
    3131-52-0

    Molecular formula
    C8H7NO2

    SMILES
    C1=CNC2=CC(=C(C=C21)O)O

    Safety labels

    Corrosive
    Corrosive

    Irritant
    Irritant

    Environmental Hazard
    Environmental

  • Odor profile

    Fragrance
    Phenolic 56.99%
    Odorless 53.61%
    Burnt 45.81%
    Smoky 29.91%
    Medicinal 24.4%
    Meaty 23.82%
    Savory 21.52%
    Vanilla 18.91%
    Animal 18.9%
    Spicy 18.77%

     

    Flavor
    Bitter 87.13%
    Mild 25.94%
    Odorless 22.76%
    Very strong 22.18%
    Indole 21.46%
    Sweet-like 21.35%
    Flat 20.41%
    Rotten 20.33%
    Almond shell 20.07%
    Scallion 20.0%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    1.3

    pKa est.
    10.09 (weak base)

    Molecular weight
    149.15 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    403°C

    Flash point

    • 209.88 ˚C est.

  • Synonyms

    • 5,6-Dihydroxyindole
    • 3131-52-0
    • 1H-Indole-5,6-diol
    • Dopamine lutine
    • 3H-INDOLE-5,6-DIOL
    • Z3OC8499KG
    • IMEXINE OAY
    • CHEBI:27404
    • DTXSID20185242
    • RefChem:587786
    • CHEBI:23781
    • DTXCID30107733
    • 412-130-9
    • Dihydroxyindole
    • MFCD00798933
    • 5,6-Dihydroxy-1H-indole
    • dhi
    • 5,6-dihydroxy indole
    • CHEMBL92636
    • UNII-Z3OC8499KG
    • indole-5,6-diol
    • EC 412-130-9
    • Calcein Red? (sodium salt)
    • SCHEMBL48994
    • orb1710547
    • SCHEMBL9739171
    • SCHEMBL9740880
    • SCHEMBL31375351
    • SCHEMBL31375356
    • Dopamine lutine;Indole-5,6-diol
    • BBL102959
    • BDBM50028548
    • MSK001139
    • STL556768
    • AKOS005258825
    • CS-W018811
    • DB01811
    • FD52256
    • HY-W018025
    • AC-22682
    • DS-10556
    • SY041253
    • DB-008889
    • NS00001889
    • C05578
    • D-3560
    • F209033
    • Q9207472
    • InChI=1/C8H7NO2/c10-7-3-5-1-2-9-6(5)4-8(7)11/h1-4,9-11
    • 25656-67-1
    • 3131-52-0

  • Applications

    5,6-Dihydroxyindole is primarily used as an intermediate and building block in the synthesis of melanin-like pigments and related polymer materials. In practice, it serves as a precursor for eumelanin-type colorants intended for coatings, inks, and pigment formulations. It is also investigated for surface-functional melanin-inspired coatings that enable adhesion and functionalization on diverse substrates, including metals and polymers. Additionally, it is studied as a monomer for melanin-inspired polymers and thin films with potential applications in electronics and sensing. The compound is considered a pigment/colorant precursor for cosmetics formulations, subject to regulatory constraints. In research contexts, it functions as a model compound for melanogenesis and is used in materials chemistry to understand oxidation and polymerization pathways of melanin.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 1.77
    methanol 3.18
    isopropanol 2.19
    water 0.9
    ethyl acetate 1.16
    n-propanol 1.61
    acetone 2.33
    n-butanol 1.76
    acetonitrile 0.34
    DMF 18.74
    toluene 0.02
    isobutanol 1.5
    1,4-dioxane 1.17
    methyl acetate 1.86
    THF 22.06
    2-butanone 2.64
    n-pentanol 2.94
    sec-butanol 2.49
    n-hexane 0.03
    ethylene glycol 8.67
    NMP 12.17
    cyclohexane 0.01
    DMSO 21.6
    n-butyl acetate 3.08
    n-octanol 2.79
    chloroform 0.07
    n-propyl acetate 2.44
    acetic acid 3.92
    dichloromethane 0.05
    cyclohexanone 1.51
    propylene glycol 5.67
    isopropyl acetate 1.48
    DMAc 38.93
    2-ethoxyethanol 26.65
    isopentanol 3.49
    n-heptane 0.1
    ethyl formate 1.51
    1,2-dichloroethane 0.08
    n-hexanol 5.47
    2-methoxyethanol 28.01
    isobutyl acetate 1.54
    tetrachloromethane 0.18
    n-pentyl acetate 3.04
    transcutol 13.9
    n-heptanol 5.41
    ethylbenzene 0.08
    MIBK 3.15
    2-propoxyethanol 28.99
    tert-butanol 8.12
    MTBE 1.52
    2-butoxyethanol 20.59
    propionic acid 2.21
    o-xylene 0.06
    formic acid 8.75
    diethyl ether 0.29
    m-xylene 0.07
    p-xylene 0.15
    chlorobenzene 0.03
    dimethyl carbonate 2.52
    n-octane 0.07
    formamide 13.53
    cyclopentanone 7.03
    2-pentanone 2.06
    anisole 1.0
    cyclopentyl methyl ether 1.39
    gamma-butyrolactone 9.38
    1-methoxy-2-propanol 23.42
    pyridine 0.26
    3-pentanone 0.81
    furfural 6.61
    n-dodecane 0.07
    diethylene glycol 36.51
    diisopropyl ether 0.36
    tert-amyl alcohol 7.82
    acetylacetone 4.34
    n-hexadecane 0.08
    acetophenone 2.11
    methyl propionate 1.78
    isopentyl acetate 3.89
    trichloroethylene 0.21
    n-nonanol 3.11
    cyclohexanol 0.72
    benzyl alcohol 1.57
    2-ethylhexanol 3.29
    isooctanol 4.94
    dipropyl ether 1.66
    1,2-dichlorobenzene 0.13
    ethyl lactate 6.04
    propylene carbonate 3.49
    n-methylformamide 6.46
    2-pentanol 1.66
    n-pentane 0.01
    1-propoxy-2-propanol 16.5
    1-methoxy-2-propyl acetate 6.61
    2-(2-methoxypropoxy) propanol 16.19
    mesitylene 0.1
    ε-caprolactone 2.91
    p-cymene 0.42
    epichlorohydrin 5.35
    1,1,1-trichloroethane 0.22
    2-aminoethanol 9.62
    morpholine-4-carbaldehyde 13.15
    sulfolane 18.44
    2,2,4-trimethylpentane 0.04
    2-methyltetrahydrofuran 3.49
    n-hexyl acetate 3.46
    isooctane 0.05
    2-(2-butoxyethoxy)ethanol 18.5
    sec-butyl acetate 1.84
    tert-butyl acetate 3.66
    decalin 0.03
    glycerin 23.03
    diglyme 31.39
    acrylic acid 2.38
    isopropyl myristate 1.96
    n-butyric acid 2.88
    acetyl acetate 0.85
    di(2-ethylhexyl) phthalate 3.07
    ethyl propionate 2.19
    nitromethane 8.5
    1,2-diethoxyethane 2.9
    benzonitrile 0.63
    trioctyl phosphate 3.18
    1-bromopropane 0.05
    gamma-valerolactone 10.57
    n-decanol 2.58
    triethyl phosphate 2.99
    4-methyl-2-pentanol 2.66
    propionitrile 0.49
    vinylene carbonate 1.65
    1,1,2-trichlorotrifluoroethane 11.53
    DMS 2.32
    cumene 0.18
    2-octanol 3.02
    2-hexanone 3.81
    octyl acetate 2.94
    limonene 0.47
    1,2-dimethoxyethane 22.26
    ethyl orthosilicate 2.92
    tributyl phosphate 2.68
    diacetone alcohol 16.21
    N,N-dimethylaniline 1.3
    acrylonitrile 0.86
    aniline 0.13
    1,3-propanediol 13.62
    bromobenzene 0.02
    dibromomethane 0.03
    1,1,2,2-tetrachloroethane 0.38
    2-methyl-cyclohexyl acetate 3.16
    tetrabutyl urea 5.1
    diisobutyl methanol 2.6
    2-phenylethanol 3.42
    styrene 0.05
    dioctyl adipate 2.9
    dimethyl sulfate 7.26
    ethyl butyrate 2.76
    methyl lactate 7.83
    butyl lactate 5.42
    diethyl carbonate 2.0
    propanediol butyl ether 10.92
    triethyl orthoformate 3.05
    p-tert-butyltoluene 0.47
    methyl 4-tert-butylbenzoate 7.17
    morpholine 2.46
    tert-butylamine 1.78
    n-dodecanol 1.96
    dimethoxymethane 8.3
    ethylene carbonate 1.33
    cyrene 15.94
    2-ethoxyethyl acetate 4.59
    2-ethylhexyl acetate 2.49
    1,2,4-trichlorobenzene 0.23
    4-methylpyridine 0.26
    dibutyl ether 1.23
    2,6-dimethyl-4-heptanol 2.6
    DEF 3.94
    dimethyl isosorbide 21.8
    tetrachloroethylene 0.41
    eugenol 10.72
    triacetin 4.14
    span 80 8.43
    1,4-butanediol 8.58
    1,1-dichloroethane 0.07
    2-methyl-1-pentanol 3.87
    methyl formate 4.03
    2-methyl-1-butanol 2.56
    n-decane 0.1
    butyronitrile 0.54
    3,7-dimethyl-1-octanol 2.98
    1-chlorooctane 0.42
    1-chlorotetradecane 0.26
    n-nonane 0.08
    undecane 0.08
    tert-butylcyclohexane 0.06
    cyclooctane 0.01
    cyclopentanol 2.36
    tetrahydropyran 0.4
    tert-amyl methyl ether 1.79
    2,5,8-trioxanonane 26.75
    1-hexene 0.1
    2-isopropoxyethanol 16.04
    2,2,2-trifluoroethanol 5.86
    methyl butyrate 3.54

    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