Azo fuchsine

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  • Identifiers

    CAS number
    3567-66-6

    Molecular formula
    C16H11N3Na2O7S2

    SMILES
    C1=CC=C(C=C1)N=NC2=C(C3=C(C=C(C=C3C=C2S(=O)(=O)[O-])S(=O)(=O)[O-])N)O.[Na+].[Na+]

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Odorless 82.7%
    Cooked 21.33%
    Savory 19.58%
    Bitter 18.38%
    Burnt 15.28%
    Grape 14.77%
    Roasted 14.27%
    Meaty 13.31%
    Milky 12.44%
    Fruity 12.15%

     

    Flavor
    Bitter 90.2%
    Odorless 33.66%
    Bland 20.78%
    Nitrile 20.56%
    Very strong 18.29%
    Bread crust 18.21%
    Taco 18.2%
    Indole 17.93%
    Roasted peanuts 17.88%
    Sweet-like 17.61%

     

    Odor impact est.
    Odorless

  • Properties

    pKa est.
    4.51 (weak acid)

    Molecular weight
    467.4 g/mol

    Flash point

    • 327.54 ˚C est.

  • Synonyms

    • Azo fuchsine
    • Acid red 33
    • 3567-66-6
    • AZOFUCHSIN
    • D.C. Red No. 33
    • C.I. ACID RED 33
    • D&C Red 33
    • D&C Red No. 33
    • Azo grenadine
    • C.I. Acid Red 33, disodium salt
    • Acid fuchsine D
    • Redusol Z
    • Azo magenta G
    • Certicol Red B
    • Fast acid magenta
    • Hexalan Red B
    • Acetyl Red B
    • Naphthalene Red B
    • Colacid Red 2A
    • Acid Red B
    • Hispacid Fuchsin B
    • Brasilan fuchsine D
    • Hexacol Red 10B
    • Amacid fuchsine 4B
    • Eniacid fuchsine BN
    • Acid Red 2A
    • Acid Fuchsin Fast B
    • Fast Acid Magenta B
    • 11427 Red
    • Edicol Supra Red 10B
    • Red 10B
    • Edicol Supra Red 10BS
    • CI 17200
    • C.I. Food Red 12
    • C.I. Reducing Agent 6
    • Edicol Supra Red 10 BS
    • D and C Red No. 33
    • Red No. 227
    • 1424 Red
    • 9DBA0SBB0L
    • C.I. 17200
    • Disodium 2-phenylazo-3,5-naphthalenedisulfonate
    • disodium;5-amino-4-hydroxy-3-phenyldiazenylnaphthalene-2,7-disulfonate
    • 5-Amino-4-hydroxy-3-(phenylazo)-2,7-naphthalenedisulfonic acid, disodium salt
    • Edicol Supra 10B
    • Edicol Supra 10BS
    • 2,7-Naphthalenedisulfonic acid, 5-amino-4-hydroxy-3-(2-phenyldiazenyl)-, sodium salt (1:2)
    • D & C Red no. 33
    • NSC-5004
    • C.I. Red 33, disodium salt
    • NSC-12190
    • NSC 5004
    • EINECS 222-656-9
    • UNII-9DBA0SBB0L
    • NSC 12190
    • CCRIS 8575
    • 2,7-Naphthalenedisulfonic acid, 5-amino-4-hydroxy-3-(phenylazo)-, disodium salt
    • Disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate
    • FOOD RED 12
    • DC RED NO. 33
    • SCHEMBL186094
    • AKA227
    • RED 33
    • SCHEMBL4806483
    • DTXSID1044562
    • SCHEMBL29354476
    • Acid Red 33, analytical standard
    • D&C RED NO. 33 [II]
    • D & C RED #33 [VANDF]
    • 2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-6-phenylazo-, disodium salt
    • AKOS024429575
    • AKOS040768118
    • FD&C RED NO. 33 (DELISTED)
    • F D & C RED #33 [VANDF]
    • ACID RED 33 (C.I. 17200)
    • FD&C RED NO. 33 (DELISTED) [II]
    • NS00019522
    • C20346
    • Q5203006
    • DISODIUM 1-HYDROXY-2-PHENYLAZO-8-AMINONAPHTHALENE-3,6-DISULFONATE
    • Disodium 5-amino-4-hydroxy-3-(phenyldiazenyl)naphthalene-2,7-disulfonate
    • disodium;5-amino-4-hydroxy-3-[(E)-phenylazo]naphthalene-2,7-disulfonate
    • 3567-66-6

  • Applications

    Azo fuchsine (CAS 3567-66-6) is a synthetic azo dye used primarily as a colorant in textiles and leather, and as a colorant in inks, coatings and plastics. It also acts as a staining reagent in microbiology and histology, enabling visualization of cellular components. In analytical settings, it can be used as a dyeing indicator for endpoint detection in certain acid–base titrations and related assays, and it serves as a chemical intermediate for synthesizing other azo dyes.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 7.02
    methanol 7.34
    isopropanol 3.23
    water 0.03
    ethyl acetate 11.15
    n-propanol 4.49
    acetone 38.68
    n-butanol 2.66
    acetonitrile 13.24
    DMF 69.04
    toluene 1.4
    isobutanol 1.76
    1,4-dioxane 22.89
    methyl acetate 15.85
    THF 79.45
    2-butanone 25.58
    n-pentanol 1.48
    sec-butanol 2.76
    n-hexane 0.01
    ethylene glycol 3.34
    NMP 53.81
    cyclohexane 0.06
    DMSO 75.77
    n-butyl acetate 5.37
    n-octanol 1.65
    chloroform 3.22
    n-propyl acetate 5.97
    acetic acid 14.13
    dichloromethane 4.29
    cyclohexanone 22.43
    propylene glycol 3.26
    isopropyl acetate 5.74
    DMAc 72.98
    2-ethoxyethanol 14.32
    isopentanol 1.61
    n-heptane 0.04
    ethyl formate 9.48
    1,2-dichloroethane 4.13
    n-hexanol 1.3
    2-methoxyethanol 47.58
    isobutyl acetate 1.64
    tetrachloromethane 0.2
    n-pentyl acetate 4.57
    transcutol 24.52
    n-heptanol 1.51
    ethylbenzene 0.33
    MIBK 3.99
    2-propoxyethanol 15.9
    tert-butanol 2.54
    MTBE 1.73
    2-butoxyethanol 9.18
    propionic acid 6.43
    o-xylene 0.67
    formic acid 13.04
    diethyl ether 3.17
    m-xylene 0.52
    p-xylene 0.52
    chlorobenzene 1.36
    dimethyl carbonate 9.76
    n-octane 0.03
    formamide 29.21
    cyclopentanone 50.37
    2-pentanone 12.03
    anisole 3.05
    cyclopentyl methyl ether 4.91
    gamma-butyrolactone 48.37
    1-methoxy-2-propanol 20.42
    pyridine 21.15
    3-pentanone 7.63
    furfural 31.47
    n-dodecane 0.05
    diethylene glycol 14.24
    diisopropyl ether 0.39
    tert-amyl alcohol 2.18
    acetylacetone 27.46
    n-hexadecane 0.06
    acetophenone 5.35
    methyl propionate 11.7
    isopentyl acetate 3.24
    trichloroethylene 8.84
    n-nonanol 1.8
    cyclohexanol 1.81
    benzyl alcohol 2.98
    2-ethylhexanol 0.7
    isooctanol 0.91
    dipropyl ether 1.92
    1,2-dichlorobenzene 1.08
    ethyl lactate 4.2
    propylene carbonate 11.85
    n-methylformamide 28.55
    2-pentanol 1.18
    n-pentane 0.03
    1-propoxy-2-propanol 8.7
    1-methoxy-2-propyl acetate 9.98
    2-(2-methoxypropoxy) propanol 9.34
    mesitylene 0.25
    ε-caprolactone 17.01
    p-cymene 0.45
    epichlorohydrin 39.65
    1,1,1-trichloroethane 1.61
    2-aminoethanol 5.55
    morpholine-4-carbaldehyde 46.57
    sulfolane 48.71
    2,2,4-trimethylpentane 0.01
    2-methyltetrahydrofuran 13.43
    n-hexyl acetate 4.56
    isooctane 0.01
    2-(2-butoxyethoxy)ethanol 13.39
    sec-butyl acetate 2.46
    tert-butyl acetate 5.02
    decalin 0.02
    glycerin 8.71
    diglyme 26.78
    acrylic acid 7.87
    isopropyl myristate 2.02
    n-butyric acid 6.45
    acetyl acetate 8.23
    di(2-ethylhexyl) phthalate 2.37
    ethyl propionate 4.95
    nitromethane 58.08
    1,2-diethoxyethane 7.43
    benzonitrile 4.45
    trioctyl phosphate 1.7
    1-bromopropane 1.06
    gamma-valerolactone 74.32
    n-decanol 1.33
    triethyl phosphate 1.79
    4-methyl-2-pentanol 0.54
    propionitrile 6.86
    vinylene carbonate 10.22
    1,1,2-trichlorotrifluoroethane 19.23
    DMS 5.45
    cumene 0.18
    2-octanol 1.02
    2-hexanone 6.2
    octyl acetate 3.25
    limonene 0.51
    1,2-dimethoxyethane 26.16
    ethyl orthosilicate 1.49
    tributyl phosphate 1.9
    diacetone alcohol 10.07
    N,N-dimethylaniline 1.4
    acrylonitrile 13.31
    aniline 3.07
    1,3-propanediol 9.1
    bromobenzene 0.92
    dibromomethane 1.85
    1,1,2,2-tetrachloroethane 5.83
    2-methyl-cyclohexyl acetate 2.73
    tetrabutyl urea 4.64
    diisobutyl methanol 0.47
    2-phenylethanol 3.6
    styrene 0.51
    dioctyl adipate 3.78
    dimethyl sulfate 13.6
    ethyl butyrate 4.4
    methyl lactate 10.04
    butyl lactate 4.44
    diethyl carbonate 2.86
    propanediol butyl ether 6.4
    triethyl orthoformate 3.11
    p-tert-butyltoluene 0.4
    methyl 4-tert-butylbenzoate 5.4
    morpholine 28.18
    tert-butylamine 0.7
    n-dodecanol 0.95
    dimethoxymethane 33.94
    ethylene carbonate 8.22
    cyrene 9.28
    2-ethoxyethyl acetate 10.19
    2-ethylhexyl acetate 2.21
    1,2,4-trichlorobenzene 2.18
    4-methylpyridine 10.68
    dibutyl ether 1.67
    2,6-dimethyl-4-heptanol 0.47
    DEF 13.24
    dimethyl isosorbide 16.39
    tetrachloroethylene 2.77
    eugenol 6.52
    triacetin 5.93
    span 80 6.01
    1,4-butanediol 1.99
    1,1-dichloroethane 2.32
    2-methyl-1-pentanol 0.93
    methyl formate 23.94
    2-methyl-1-butanol 1.54
    n-decane 0.07
    butyronitrile 4.63
    3,7-dimethyl-1-octanol 0.99
    1-chlorooctane 0.47
    1-chlorotetradecane 0.22
    n-nonane 0.05
    undecane 0.06
    tert-butylcyclohexane 0.01
    cyclooctane 0.02
    cyclopentanol 4.08
    tetrahydropyran 9.82
    tert-amyl methyl ether 1.52
    2,5,8-trioxanonane 20.11
    1-hexene 0.13
    2-isopropoxyethanol 6.03
    2,2,2-trifluoroethanol 5.69
    methyl butyrate 6.71

    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