2,5-Dihydroxybenzoic acid

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  • Identifiers

    CAS number
    490-79-9

    Molecular formula
    C7H6O4

    SMILES
    C1=CC(=C(C=C1O)C(=O)O)O

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Phenolic 68.63%
    Odorless 59.05%
    Balsamic 32.59%
    Burnt 32.47%
    Medicinal 31.75%
    Nutty 31.37%
    Bitter 27.91%
    Vanilla 27.24%
    Smoky 24.93%
    Aromatic 24.11%

     

    Flavor
    Phenolic 64.09%
    Odorless 49.25%
    Mild 48.3%
    Nutty 46.88%
    Faint 29.2%
    Bitter 29.13%
    Sour 28.08%
    Very mild 25.41%
    Urine 24.3%
    Musty 24.03%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    1.6

    pKa est.
    8.78 (weak base)

    Molecular weight
    154.12 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    357°C

    Melting point expt.

    • 199.5 °C

    Flash point

    • 184.65 ˚C est.

    Solubility expt.

    • 5.0 mg/mL at 5 °C

  • Synonyms

    • 2,5-DIHYDROXYBENZOIC ACID
    • gentisic acid
    • 490-79-9
    • Benzoic acid, 2,5-dihydroxy-
    • 5-Hydroxysalicylic acid
    • Gensigen
    • Gensigon
    • Hydroquinonecarboxylic acid
    • 2,5-Dhba
    • 2,5-Dioxybenzoic acid
    • Salicylic acid, 5-hydroxy-
    • Kyselina gentisinova
    • Acido gentisico
    • Acide gentisique
    • Acidum gentisicum
    • VP36V95O3T
    • NSC-27224
    • DTXSID4060078
    • CHEBI:17189
    • RefChem:639843
    • DTXCID6040660
    • 207-718-5
    • Gentisinic acid
    • MFCD00002460
    • Gentisic acid [INN]
    • Gentisinate
    • Mesalazine EP Impurity G
    • 3,6-dihydroxybenzoic acid
    • 2,5-Dihydroxy benzoic acid
    • NSC 27224
    • Kyselina 2,5-dihydroxybenzoova
    • CHEMBL1461
    • BENZOIC ACID,2,5-DIHYDROXY
    • Gentinatre
    • Gentalpin
    • Gentasol
    • Gentidol
    • Gentisan
    • Gentisod
    • Legential
    • Nagentis
    • Casate
    • Gabail
    • Nagent
    • Carboxyhydroquinone
    • Casate sodium
    • Gensalate sodium
    • Sodium-Gent
    • WLN: QVR BQ EQ
    • GENTISATE SODIUM
    • Kyselina gentisinova [Czech]
    • NSC8512
    • Acide gentisique [INN-French]
    • Acido gentisico [INN-Spanish]
    • Acidum gentisicum [INN-Latin]
    • EINECS 207-718-5
    • Acido 2,5-diidrossibenzoico [Italian]
    • BRN 2209119
    • gentisicacid
    • Kyselina 2,5-dihydroxybenzoova [Czech]
    • Acido 2,5-diidrossibenzoico
    • UNII-VP36V95O3T
    • AI3-60431
    • Dihydroxybenzoicacid
    • GTQ
    • 2,5-Dioxybenzoate
    • GENOP
    • 5-hydroxy-Salicylate
    • 3,6-Dihydroxybenzoate
    • Spectrum_001241
    • 2,5dihydroxybenzoic acid
    • 5-hydroxy-Salicylic acid
    • Spectrum2_000773
    • Spectrum3_001326
    • Spectrum4_001821
    • Spectrum5_000581
    • 2,5,dihydroxybenzoic acid
    • bmse000326
    • GENTISIC ACID [II]
    • GENTISIC ACID [MI]
    • SCHEMBL3690
    • 2,5-dihydroxy-benzoic acid
    • 2,5-Dihydroxybenzoate, VI
    • NCIOpen2_000913
    • Oprea1_039290
    • BSPBio_003051
    • KBioGR_002487
    • KBioSS_001721
    • 4-10-00-01441 (Beilstein Handbook Reference)
    • MLS002207134
    • DivK1c_000538
    • SCHEMBL446275
    • SPBio_000846
    • orb1304923
    • SCHEMBL6630470
    • SCHEMBL6631336
    • SCHEMBL6632202
    • GENTISIC ACID [WHO-DD]
    • SCHEMBL29349919
    • HMS501K20
    • KBio1_000538
    • KBio2_001721
    • KBio2_004289
    • KBio2_006857
    • KBio3_002271
    • 2,5-Dihydroxybenzoic acid, tech
    • NINDS_000538
    • 2,5-Dihydroxybenzoic acid, 98%
    • HMS5082M13
    • BB_NC-02255
    • HY-W001179R
    • KSB81567
    • MSK40048
    • NSC27224
    • NSC49098
    • BBL013232
    • BDBM50335808
    • CCG-40154
    • CK2181
    • EBC-48155
    • NSC-49098
    • s3799
    • SBB058777
    • STK426343
    • 2,5-Dihydroxybenzoic acid (Standard)
    • AKOS003267857
    • CS-W001179
    • 490-79-9

  • Applications

    2,5-Dihydroxybenzoic acid (CAS 490-79-9) is primarily used as an intermediate in organic synthesis across several industries. It serves as a building block for pharmaceutical compounds and for the synthesis of organic dyes and pigments. It is also evaluated as an antioxidant and stabilizing additive in polymer formulations, helping to improve durability of plastics and coatings. In cosmetics and personal care, it is studied as a polyphenolic-type ingredient with potential antioxidant activity. It may be employed as a precursor in coating and ink chemistries, where its phenolic functionality can participate in further derivatization. In analytical contexts, it may be used as a reference or reagent in chemical analyses. Note: use is subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 31.88
    methanol 90.3
    isopropanol 24.07
    water 7.7
    ethyl acetate 13.12
    n-propanol 22.73
    acetone 69.27
    n-butanol 29.56
    acetonitrile 12.21
    DMF 492.72
    toluene 1.05
    isobutanol 18.87
    1,4-dioxane 23.42
    methyl acetate 20.48
    THF 1931.53
    2-butanone 33.92
    n-pentanol 34.79
    sec-butanol 21.44
    n-hexane 0.89
    ethylene glycol 68.41
    NMP 112.71
    cyclohexane 0.19
    DMSO 958.71
    n-butyl acetate 20.21
    n-octanol 24.9
    chloroform 2.54
    n-propyl acetate 23.24
    acetic acid 10.75
    dichloromethane 3.34
    cyclohexanone 26.3
    propylene glycol 25.64
    isopropyl acetate 16.21
    DMAc 302.19
    2-ethoxyethanol 123.61
    isopentanol 43.57
    n-heptane 1.56
    ethyl formate 22.78
    1,2-dichloroethane 6.87
    n-hexanol 47.94
    2-methoxyethanol 188.64
    isobutyl acetate 8.34
    tetrachloromethane 4.51
    n-pentyl acetate 13.11
    transcutol 23.36
    n-heptanol 34.7
    ethylbenzene 2.68
    MIBK 43.97
    2-propoxyethanol 136.88
    tert-butanol 96.26
    MTBE 23.88
    2-butoxyethanol 66.3
    propionic acid 9.08
    o-xylene 2.25
    formic acid 40.33
    diethyl ether 8.62
    m-xylene 3.01
    p-xylene 3.04
    chlorobenzene 1.06
    dimethyl carbonate 33.45
    n-octane 0.87
    formamide 76.81
    cyclopentanone 190.71
    2-pentanone 41.84
    anisole 20.69
    cyclopentyl methyl ether 58.43
    gamma-butyrolactone 135.7
    1-methoxy-2-propanol 129.62
    pyridine 7.17
    3-pentanone 15.25
    furfural 50.29
    n-dodecane 1.02
    diethylene glycol 144.24
    diisopropyl ether 5.99
    tert-amyl alcohol 62.17
    acetylacetone 49.59
    n-hexadecane 1.08
    acetophenone 20.67
    methyl propionate 24.47
    isopentyl acetate 17.5
    trichloroethylene 7.55
    n-nonanol 23.15
    cyclohexanol 11.17
    benzyl alcohol 16.32
    2-ethylhexanol 22.95
    isooctanol 26.65
    dipropyl ether 19.66
    1,2-dichlorobenzene 2.59
    ethyl lactate 24.31
    propylene carbonate 27.41
    n-methylformamide 129.38
    2-pentanol 19.91
    n-pentane 0.42
    1-propoxy-2-propanol 65.17
    1-methoxy-2-propyl acetate 31.26
    2-(2-methoxypropoxy) propanol 40.19
    mesitylene 3.44
    ε-caprolactone 21.66
    p-cymene 4.64
    epichlorohydrin 154.32
    1,1,1-trichloroethane 5.74
    2-aminoethanol 66.85
    morpholine-4-carbaldehyde 93.29
    sulfolane 202.78
    2,2,4-trimethylpentane 0.7
    2-methyltetrahydrofuran 107.1
    n-hexyl acetate 17.75
    isooctane 1.02
    2-(2-butoxyethoxy)ethanol 42.79
    sec-butyl acetate 12.93
    tert-butyl acetate 35.07
    decalin 0.7
    glycerin 71.84
    diglyme 82.71
    acrylic acid 9.53
    isopropyl myristate 11.75
    n-butyric acid 15.77
    acetyl acetate 7.02
    di(2-ethylhexyl) phthalate 10.28
    ethyl propionate 26.16
    nitromethane 62.03
    1,2-diethoxyethane 10.53
    benzonitrile 7.85
    trioctyl phosphate 14.19
    1-bromopropane 2.91
    gamma-valerolactone 84.59
    n-decanol 19.17
    triethyl phosphate 15.21
    4-methyl-2-pentanol 23.97
    propionitrile 13.81
    vinylene carbonate 14.6
    1,1,2-trichlorotrifluoroethane 60.73
    DMS 9.35
    cumene 3.9
    2-octanol 18.49
    2-hexanone 37.89
    octyl acetate 16.21
    limonene 5.18
    1,2-dimethoxyethane 192.96
    ethyl orthosilicate 13.89
    tributyl phosphate 10.09
    diacetone alcohol 86.26
    N,N-dimethylaniline 23.93
    acrylonitrile 20.36
    aniline 3.53
    1,3-propanediol 74.4
    bromobenzene 0.83
    dibromomethane 1.88
    1,1,2,2-tetrachloroethane 10.42
    2-methyl-cyclohexyl acetate 15.21
    tetrabutyl urea 20.46
    diisobutyl methanol 16.89
    2-phenylethanol 23.8
    styrene 1.82
    dioctyl adipate 13.65
    dimethyl sulfate 83.8
    ethyl butyrate 21.13
    methyl lactate 41.15
    butyl lactate 13.86
    diethyl carbonate 13.13
    propanediol butyl ether 29.06
    triethyl orthoformate 14.22
    p-tert-butyltoluene 5.51
    methyl 4-tert-butylbenzoate 31.26
    morpholine 44.6
    tert-butylamine 32.02
    n-dodecanol 14.93
    dimethoxymethane 213.84
    ethylene carbonate 13.45
    cyrene 48.72
    2-ethoxyethyl acetate 11.62
    2-ethylhexyl acetate 11.66
    1,2,4-trichlorobenzene 2.98
    4-methylpyridine 9.38
    dibutyl ether 8.79
    2,6-dimethyl-4-heptanol 16.89
    DEF 59.51
    dimethyl isosorbide 69.65
    tetrachloroethylene 8.59
    eugenol 36.59
    triacetin 10.85
    span 80 23.71
    1,4-butanediol 49.54
    1,1-dichloroethane 3.05
    2-methyl-1-pentanol 31.68
    methyl formate 93.23
    2-methyl-1-butanol 27.18
    n-decane 1.36
    butyronitrile 19.12
    3,7-dimethyl-1-octanol 18.05
    1-chlorooctane 6.66
    1-chlorotetradecane 3.49
    n-nonane 1.1
    undecane 1.18
    tert-butylcyclohexane 1.15
    cyclooctane 0.26
    cyclopentanol 44.77
    tetrahydropyran 14.14
    tert-amyl methyl ether 24.29
    2,5,8-trioxanonane 73.79
    1-hexene 3.37
    2-isopropoxyethanol 64.14
    2,2,2-trifluoroethanol 18.35
    methyl butyrate 39.28

    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