1-Naphthalenol, 4-[(4-ethoxyphenyl)azo]-

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  • Identifiers

    CAS number
    6535-42-8

    Molecular formula
    C18H16N2O2

    SMILES
    CCOC1=CC=C(C=C1)N=NC2=CC=C(C3=CC=CC=C32)O

    Safety labels

  • Odor profile

    Fragrance
    Floral 54.51%
    Sweet 52.33%
    Vanilla 36.25%
    Powdery 32.99%
    Fruity 32.12%
    Spicy 30.68%
    Phenolic 29.81%
    Neroli 29.8%
    Animal 27.7%
    Grape 27.15%

     

    Flavor
    Bitter 85.53%
    Very strong 20.81%
    Indole 20.51%
    Nitrile 20.42%
    Orange blossom 20.3%
    Orange flower 19.74%
    Fruity 19.56%
    Mild 19.51%
    Moth ball 19.48%
    Naphthelene 19.39%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    4.9

    pKa est.
    7.7 (neutral)

    Molecular weight
    292.3 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    551°C

    Flash point

    • 243.59 ˚C est.

  • Synonyms

    • Solvent red 3
    • 6535-42-8
    • Fat Brown B
    • C.I. Solvent Red 3
    • 1-Naphthalenol, 4-[(4-ethoxyphenyl)azo]-
    • 4-[(4-ethoxyphenyl)diazenyl]naphthalen-1-ol
    • CI 12010
    • 1-Naphthalenol, 4-((4-ethoxyphenyl)azo)-
    • 4-((4-Ethoxyphenyl)diazenyl)naphthalen-1-ol
    • XNW2E18207
    • MFCD00009691
    • 1-Naphthalenol, 4-(2-(4-ethoxyphenyl)diazenyl)-
    • 4-[(1E)-2-(4-ethoxyphenyl)diazen-1-yl]naphthalen-1-ol
    • UNII-XNW2E18207
    • EINECS 229-439-8
    • CERES BROWN B
    • 4-((4-Ethoxyphenyl)azo)-1-naphthalenol
    • Fat brown b, technical grade
    • SCHEMBL157562
    • SCHEMBL341535
    • DTXSID6064402
    • SCHEMBL10429905
    • SCHEMBL29912875
    • MSK5890
    • 4-((4-Ethoxyphenyl)azo)naphthol
    • JSEYDVLGSMLKDL-UHFFFAOYSA-N
    • BRUN FONCE AU GRAS W 8201
    • AKOS003416718
    • 4-[(4-ethoxyphenyl)diazenyl]-alpha-naphthol
    • NS00047444
    • 4-((4-ETHOXYPHENYL)AZO)-1-NAPHTHOL
    • (4E)-4-[(4-ethoxyphenyl)hydrazono]naphthalen-1-one
    • Q27293920
    • 6535-42-8

  • Applications

    1-Naphthalenol, 4-[(4-ethoxyphenyl)azo]- (CAS 6535-42-8) is commonly used as an intermediate in the synthesis of azo dyes, serving as a colorant precursor for azo pigments. In the textile sector, it is employed as a color precursor for dyeing fabrics; in printing inks and coatings, it participates in pigment formulations to achieve the desired hues; in plastics and polymer formulations, it may be used to color resins and polymer blends; in leather finishing, it is considered for color development on hides and related materials.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 5.13
    methanol 5.3
    isopropanol 2.97
    water 0.0
    ethyl acetate 28.71
    n-propanol 5.55
    acetone 26.55
    n-butanol 5.44
    acetonitrile 15.35
    DMF 33.76
    toluene 22.4
    isobutanol 3.54
    1,4-dioxane 75.1
    methyl acetate 34.73
    THF 191.3
    2-butanone 33.43
    n-pentanol 7.06
    sec-butanol 4.38
    n-hexane 1.04
    ethylene glycol 1.3
    NMP 24.82
    cyclohexane 1.09
    DMSO 92.89
    n-butyl acetate 29.18
    n-octanol 2.98
    chloroform 163.98
    n-propyl acetate 28.4
    acetic acid 17.19
    dichloromethane 260.39
    cyclohexanone 50.42
    propylene glycol 1.79
    isopropyl acetate 19.77
    DMAc 72.16
    2-ethoxyethanol 22.7
    isopentanol 5.97
    n-heptane 1.39
    ethyl formate 13.93
    1,2-dichloroethane 155.99
    n-hexanol 6.56
    2-methoxyethanol 24.93
    isobutyl acetate 19.25
    tetrachloromethane 5.48
    n-pentyl acetate 12.94
    transcutol 166.45
    n-heptanol 3.86
    ethylbenzene 12.02
    MIBK 17.04
    2-propoxyethanol 27.86
    tert-butanol 5.69
    MTBE 14.97
    2-butoxyethanol 14.38
    propionic acid 10.11
    o-xylene 9.3
    formic acid 4.72
    diethyl ether 21.34
    m-xylene 8.59
    p-xylene 14.64
    chlorobenzene 34.88
    dimethyl carbonate 22.87
    n-octane 0.67
    formamide 13.55
    cyclopentanone 67.26
    2-pentanone 21.18
    anisole 35.48
    cyclopentyl methyl ether 31.88
    gamma-butyrolactone 81.32
    1-methoxy-2-propanol 16.61
    pyridine 76.23
    3-pentanone 25.77
    furfural 75.86
    n-dodecane 0.71
    diethylene glycol 18.73
    diisopropyl ether 6.14
    tert-amyl alcohol 6.58
    acetylacetone 50.73
    n-hexadecane 0.86
    acetophenone 32.36
    methyl propionate 24.84
    isopentyl acetate 28.38
    trichloroethylene 273.23
    n-nonanol 3.92
    cyclohexanol 7.05
    benzyl alcohol 17.82
    2-ethylhexanol 7.76
    isooctanol 4.3
    dipropyl ether 21.8
    1,2-dichlorobenzene 33.85
    ethyl lactate 12.37
    propylene carbonate 32.45
    n-methylformamide 13.06
    2-pentanol 3.85
    n-pentane 0.49
    1-propoxy-2-propanol 19.82
    1-methoxy-2-propyl acetate 43.38
    2-(2-methoxypropoxy) propanol 29.75
    mesitylene 4.88
    ε-caprolactone 41.99
    p-cymene 7.65
    epichlorohydrin 191.36
    1,1,1-trichloroethane 54.26
    2-aminoethanol 2.96
    morpholine-4-carbaldehyde 58.47
    sulfolane 84.06
    2,2,4-trimethylpentane 0.76
    2-methyltetrahydrofuran 47.88
    n-hexyl acetate 14.46
    isooctane 0.47
    2-(2-butoxyethoxy)ethanol 34.0
    sec-butyl acetate 21.14
    tert-butyl acetate 25.71
    decalin 1.78
    glycerin 5.26
    diglyme 93.94
    acrylic acid 11.45
    isopropyl myristate 10.3
    n-butyric acid 13.79
    acetyl acetate 27.73
    di(2-ethylhexyl) phthalate 10.69
    ethyl propionate 27.35
    nitromethane 59.28
    1,2-diethoxyethane 60.29
    benzonitrile 24.68
    trioctyl phosphate 6.15
    1-bromopropane 39.48
    gamma-valerolactone 85.5
    n-decanol 3.43
    triethyl phosphate 21.39
    4-methyl-2-pentanol 3.73
    propionitrile 15.3
    vinylene carbonate 36.87
    1,1,2-trichlorotrifluoroethane 63.54
    DMS 36.57
    cumene 7.96
    2-octanol 2.64
    2-hexanone 26.4
    octyl acetate 10.54
    limonene 9.4
    1,2-dimethoxyethane 74.56
    ethyl orthosilicate 19.53
    tributyl phosphate 10.56
    diacetone alcohol 21.47
    N,N-dimethylaniline 20.42
    acrylonitrile 25.26
    aniline 19.18
    1,3-propanediol 6.62
    bromobenzene 44.62
    dibromomethane 118.18
    1,1,2,2-tetrachloroethane 143.82
    2-methyl-cyclohexyl acetate 25.05
    tetrabutyl urea 14.01
    diisobutyl methanol 6.65
    2-phenylethanol 18.14
    styrene 16.14
    dioctyl adipate 19.92
    dimethyl sulfate 42.01
    ethyl butyrate 30.02
    methyl lactate 11.88
    butyl lactate 11.19
    diethyl carbonate 24.52
    propanediol butyl ether 8.94
    triethyl orthoformate 26.74
    p-tert-butyltoluene 7.01
    methyl 4-tert-butylbenzoate 24.69
    morpholine 57.38
    tert-butylamine 3.18
    n-dodecanol 3.18
    dimethoxymethane 50.8
    ethylene carbonate 28.18
    cyrene 25.93
    2-ethoxyethyl acetate 33.26
    2-ethylhexyl acetate 23.19
    1,2,4-trichlorobenzene 44.97
    4-methylpyridine 44.25
    dibutyl ether 14.47
    2,6-dimethyl-4-heptanol 6.65
    DEF 29.98
    dimethyl isosorbide 64.8
    tetrachloroethylene 72.08
    eugenol 24.28
    triacetin 30.77
    span 80 16.5
    1,4-butanediol 3.08
    1,1-dichloroethane 64.57
    2-methyl-1-pentanol 8.94
    methyl formate 14.58
    2-methyl-1-butanol 5.75
    n-decane 1.06
    butyronitrile 11.16
    3,7-dimethyl-1-octanol 5.24
    1-chlorooctane 4.44
    1-chlorotetradecane 2.58
    n-nonane 0.83
    undecane 0.85
    tert-butylcyclohexane 1.58
    cyclooctane 0.49
    cyclopentanol 7.04
    tetrahydropyran 46.38
    tert-amyl methyl ether 14.63
    2,5,8-trioxanonane 67.99
    1-hexene 6.7
    2-isopropoxyethanol 17.3
    2,2,2-trifluoroethanol 7.12
    methyl butyrate 31.14

    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