Pyroglutamic Acid

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  • Identifiers

    CAS number
    98-79-3

    Molecular formula
    C5H7NO3

    SMILES
    C1CC(=O)N[C@@H]1C(=O)O

    Safety labels

    Corrosive
    Corrosive

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Sweet 57.9%
    Odorless 54.98%
    Caramellic 36.3%
    Nutty 32.05%
    Burnt 30.59%
    Ethereal 26.83%
    Buttery 21.49%
    Roasted 19.09%
    Popcorn 18.82%
    Bitter 17.98%

     

    Flavor
    Odorless 50.42%
    Bitter 35.76%
    Very mild 28.83%
    Nutty 22.45%
    Yeast 21.63%
    Urine 20.59%
    Mild 20.22%
    Sweet-like 20.2%
    Taco 20.0%
    Formyl 19.97%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    -0.8

    pKa est.
    6.9 (neutral)

    Molecular weight
    129.11 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    375°C

    Melting point expt.

    • 184.7 °C

    Flash point

    • 190.85 ˚C est.

    Solubility expt.

    • >19.4 [ug/mL] (The mean of the results at pH 7.4)
    • 476000 mg/L (at 13 °C)
    • 476.0 mg/mL at 13 °C

  • Synonyms

    • L-Pyroglutamic acid
    • 98-79-3
    • Pyroglutamic acid
    • Pidolic acid
    • 5-oxo-L-proline
    • (2S)-5-oxopyrrolidine-2-carboxylic acid
    • H-Pyr-OH
    • (S)-5-Oxopyrrolidine-2-carboxylic Acid
    • Pyroglutamate
    • pyroglu
    • GLUTIMIC ACID
    • L-Proline, 5-oxo-
    • 5-OXOPROLINE
    • (S)-(-)-2-Pyrrolidone-5-carboxylic acid
    • 5-L-Oxoproline
    • L-5-Oxoproline
    • Proline, 5-oxo-
    • Pidolidone
    • Pidolate
    • Pyrrolidonecarboxylic acid
    • AJIDEW A-100
    • (-)-2-Pyrrolidone-5-carboxylic acid
    • (S)-PYROGLUTAMIC ACID
    • Acide pidolique
    • Acido pidolico
    • 5-Carboxy-2-pyrrolidinone
    • L-5-Carboxy-2-pyrrolidinone
    • L-GLUTIMINIC ACID
    • L-5-Oxo-2-pyrrolidinecarboxylic acid
    • oxo-proline
    • GLUTIMINIC ACID
    • Pidolic acid [INN]
    • L-Pyroglutamate
    • 2-Pyrrolidinone-5-carboxylic acid
    • 5-Pyrrolidinone-2-carboxylic acid
    • (S)-5-Oxo-2-pyrrolidinecarboxylic acid
    • Acidum pidolicum
    • Pyroglutamic acid, l-
    • 2-L-Pyrrolidone-5-carboxylic acid
    • L-GLUTIMIC ACID
    • L-pca
    • 5-Pyrrolidone-2-carboxylic acid
    • Pyr-OH
    • 2-Pyrrolidone-5-carboxylate
    • L-5-Pyrrolidone-2-carboxylic acid
    • L-2-PYRROLIDONE-5-CARBOXYLIC ACID
    • l-pyrrolidone carboxylic acid
    • L-Glutamic acid gamma-lactam
    • Acide pidolique [INN-French]
    • Acido pidolico [INN-Spanish]
    • Acidum pidolicum [INN-Latin]
    • Glutiminate
    • Glutimate
    • NSC 143034
    • L-Glutiminate
    • L-Glutimate
    • (5S)-2-Oxopyrrolidine-5-carboxylic acid
    • PYRROLIDINONECARBOXYLIC ACID
    • 5-OXO-2-PYRROLIDINECARBOXYLIC ACID
    • L-PYRROLIDONECARBOXYLIC ACID
    • Proline, 5-oxo-, L-
    • 2-Oxopyrrolidine-5-carboxylic acid
    • Pidolic acid [INN:BAN]
    • NSC 9966
    • EINECS 202-700-3
    • L-PYRROLIDINONECARBOXYLIC ACID
    • PYRROLIDONE-5-CARBOXYLIC ACID
    • (S)-Pyroglutamate
    • OXOPROLINE
    • (-)-Pyroglutamate
    • 2-Benzothiazolesulfenic acid morpholide
    • NSC-760414
    • SZB83O1W42
    • DTXSID6046260
    • CHEBI:18183
    • Pyrrolidinonecarboxylate
    • Ajidew A 100
    • NSC9966
    • L-Pyrrolidonecarboxylate
    • Oxopyrrolidinecarboxylate
    • (-)-Pyroglutamic acid
    • L-Pyrrolidinonecarboxylate
    • Pyrrolidone-5-carboxylate
    • L-Glutamic acid g-lactam
    • MFCD00005272
    • (S)-2-Pyrrolidone-5-carboxylic acid
    • NSC-143034
    • Oxopyrrolidinecarboxylic acid
    • 2-Pyrrolidinone-5-carboxylate
    • 5-Pyrrolidinone-2-carboxylate
    • PIDOLIC ACID [WHO-DD]
    • 2-L-Pyrrolidone-5-carboxylate
    • L-2-Pyrrolidone-5-carboxylate
    • DTXCID4026260
    • L-PYROGLUTAMIC ACID [MI]
    • L-5-Oxo-2-pyrrolidinecarboxylate
    • (S)-2-Pyrrolidone-5-carboxylate
    • (-)-2-Pyrrolidone-5-carboxylate
    • 2-Oxopyrrolidine-5(S)-carboxylate
    • PYROGLUTAMIC ACID [USP-RS]
    • (S)-5-Oxo-2-pyrrolidinecarboxylate
    • (5S)-2-Oxopyrrolidine-5-carboxylate
    • pyrrolidone-COO
    • (S)-(-)-g-Butyrolactam-g-carboxylate
    • 2-Oxopyrrolidine-5(S)-carboxylic acid
    • (S)-(-)-2-Pyrrolidone-5-carboxylate
    • NCGC00160613-01
    • (S)-(-)-g-Butyrolactam-g-carboxylic acid
    • (S)-(-)-gamma-Butyrolactam-gamma-carboxylate
    • (S)-(-)-gamma-Butyrolactam-gamma-carboxylic acid
    • Acide pidolique (INN-French)
    • Acido pidolico (INN-Spanish)
    • Acidum pidolicum (INN-Latin)
    • PYROGLUTAMIC ACID (USP-RS)
    • PYRROLIDONE-CARBOXYLATE
    • CAS-98-79-3
    • pGlu-OH
    • SMR000857158
    • glutamic acid lactam
    • 16891-48-8
    • UNII-SZB83O1W42
    • 5oxoproline
    • pidolic-acid
    • pGlu
    • 5LOxoproline
    • 5OxoLproline
    • L5Oxoproline
    • NSC143034

  • Applications

    Pyroglutamic acid is primarily used as a versatile intermediate in organic synthesis, serving as a building block for pharmaceutical intermediates and other fine chemicals with chiral architecture. In cosmetics and personal care, it is a precursor to pyrrolidone carboxylic acid (PCA), a humectant and conditioning component derived from pyroglutamate derivatives. In polymers and materials science, it is employed as a precursor to lactam-based monomers and to polypeptide synthesis, enabling specialty polymers and bio-based materials. In general industrial manufacturing, it functions as a useful starting material for the preparation of diverse derivatives and scaffolds in synthetic chemistry, supporting process development and scale-up.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 85.94
    methanol 305.35
    isopropanol 36.51
    water 833.42
    ethyl acetate 2.42
    n-propanol 33.23
    acetone 15.1
    n-butanol 26.06
    acetonitrile 8.44
    DMF 338.4
    toluene 1.23
    isobutanol 23.75
    1,4-dioxane 25.33
    methyl acetate 4.44
    THF 27.81
    2-butanone 5.25
    n-pentanol 19.25
    sec-butanol 19.98
    n-hexane 0.58
    ethylene glycol 124.47
    NMP 127.16
    cyclohexane 0.44
    DMSO 284.38
    n-butyl acetate 4.45
    n-octanol 7.48
    chloroform 3.17
    n-propyl acetate 3.4
    acetic acid 82.26
    dichloromethane 6.92
    cyclohexanone 11.52
    propylene glycol 58.49
    isopropyl acetate 2.97
    DMAc 135.05
    2-ethoxyethanol 103.72
    isopentanol 25.85
    n-heptane 0.58
    ethyl formate 19.34
    1,2-dichloroethane 5.51
    n-hexanol 10.68
    2-methoxyethanol 179.11
    isobutyl acetate 1.92
    tetrachloromethane 1.1
    n-pentyl acetate 5.02
    transcutol 116.25
    n-heptanol 8.36
    ethylbenzene 1.39
    MIBK 7.12
    2-propoxyethanol 44.8
    tert-butanol 40.88
    MTBE 6.79
    2-butoxyethanol 32.79
    propionic acid 17.14
    o-xylene 2.22
    formic acid 398.35
    diethyl ether 4.99
    m-xylene 2.08
    p-xylene 1.94
    chlorobenzene 1.34
    dimethyl carbonate 6.77
    n-octane 0.42
    formamide 326.56
    cyclopentanone 16.94
    2-pentanone 6.09
    anisole 5.99
    cyclopentyl methyl ether 7.28
    gamma-butyrolactone 27.39
    1-methoxy-2-propanol 72.62
    pyridine 8.46
    3-pentanone 3.04
    furfural 55.3
    n-dodecane 0.33
    diethylene glycol 88.39
    diisopropyl ether 1.8
    tert-amyl alcohol 27.99
    acetylacetone 11.27
    n-hexadecane 0.34
    acetophenone 7.94
    methyl propionate 4.0
    isopentyl acetate 5.55
    trichloroethylene 6.27
    n-nonanol 7.11
    cyclohexanol 10.01
    benzyl alcohol 13.01
    2-ethylhexanol 4.93
    isooctanol 6.71
    dipropyl ether 3.37
    1,2-dichlorobenzene 2.13
    ethyl lactate 9.71
    propylene carbonate 14.67
    n-methylformamide 131.65
    2-pentanol 11.41
    n-pentane 0.62
    1-propoxy-2-propanol 21.76
    1-methoxy-2-propyl acetate 8.89
    2-(2-methoxypropoxy) propanol 31.74
    mesitylene 1.74
    ε-caprolactone 14.13
    p-cymene 1.62
    epichlorohydrin 25.4
    1,1,1-trichloroethane 1.71
    2-aminoethanol 134.38
    morpholine-4-carbaldehyde 116.92
    sulfolane 64.42
    2,2,4-trimethylpentane 0.4
    2-methyltetrahydrofuran 11.54
    n-hexyl acetate 6.52
    isooctane 0.32
    2-(2-butoxyethoxy)ethanol 46.72
    sec-butyl acetate 2.39
    tert-butyl acetate 5.64
    decalin 0.36
    glycerin 122.49
    diglyme 79.34
    acrylic acid 26.72
    isopropyl myristate 3.08
    n-butyric acid 17.64
    acetyl acetate 3.32
    di(2-ethylhexyl) phthalate 7.34
    ethyl propionate 2.79
    nitromethane 73.81
    1,2-diethoxyethane 12.52
    benzonitrile 6.58
    trioctyl phosphate 5.29
    1-bromopropane 2.14
    gamma-valerolactone 52.9
    n-decanol 5.34
    triethyl phosphate 4.67
    4-methyl-2-pentanol 8.85
    propionitrile 4.72
    vinylene carbonate 15.59
    1,1,2-trichlorotrifluoroethane 40.16
    DMS 5.8
    cumene 1.57
    2-octanol 5.26
    2-hexanone 4.81
    octyl acetate 4.7
    limonene 2.01
    1,2-dimethoxyethane 87.81
    ethyl orthosilicate 4.33
    tributyl phosphate 5.58
    diacetone alcohol 23.85
    N,N-dimethylaniline 8.0
    acrylonitrile 9.94
    aniline 4.66
    1,3-propanediol 107.04
    bromobenzene 0.94
    dibromomethane 3.41
    1,1,2,2-tetrachloroethane 5.73
    2-methyl-cyclohexyl acetate 4.96
    tetrabutyl urea 10.45
    diisobutyl methanol 4.16
    2-phenylethanol 9.52
    styrene 1.33
    dioctyl adipate 5.73
    dimethyl sulfate 21.72
    ethyl butyrate 4.12
    methyl lactate 18.2
    butyl lactate 10.47
    diethyl carbonate 3.51
    propanediol butyl ether 38.01
    triethyl orthoformate 4.86
    p-tert-butyltoluene 1.6
    methyl 4-tert-butylbenzoate 14.03
    morpholine 36.15
    tert-butylamine 13.69
    n-dodecanol 3.94
    dimethoxymethane 57.89
    ethylene carbonate 10.61
    cyrene 35.93
    2-ethoxyethyl acetate 9.02
    2-ethylhexyl acetate 3.74
    1,2,4-trichlorobenzene 2.69
    4-methylpyridine 8.81
    dibutyl ether 3.94
    2,6-dimethyl-4-heptanol 4.16
    DEF 21.74
    dimethyl isosorbide 36.72
    tetrachloroethylene 5.17
    eugenol 20.67
    triacetin 9.41
    span 80 20.87
    1,4-butanediol 64.91
    1,1-dichloroethane 2.14
    2-methyl-1-pentanol 17.73
    methyl formate 86.04
    2-methyl-1-butanol 20.96
    n-decane 0.52
    butyronitrile 7.1
    3,7-dimethyl-1-octanol 7.0
    1-chlorooctane 1.51
    1-chlorotetradecane 0.76
    n-nonane 0.49
    undecane 0.4
    tert-butylcyclohexane 0.37
    cyclooctane 0.29
    cyclopentanol 15.91
    tetrahydropyran 6.96
    tert-amyl methyl ether 6.5
    2,5,8-trioxanonane 60.64
    1-hexene 1.68
    2-isopropoxyethanol 42.93
    2,2,2-trifluoroethanol 45.96
    methyl butyrate 6.34

    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