Carbocysteine

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  • Identifiers

    CAS number
    638-23-3

    Molecular formula
    C5H9NO4S

    SMILES
    C([C@@H](C(=O)O)N)SCC(=O)O

    Safety labels

    Corrosive
    Corrosive

  • Odor profile

    Fragrance
    Sulfurous 58.1%
    Meaty 55.22%
    Savory 48.86%
    Odorless 48.3%
    Roasted 35.35%
    Cooked 32.38%
    Onion 24.65%
    Cheesy 23.25%
    Alliaceous 21.1%
    Garlic 20.08%

     

    Flavor
    Odorless 57.03%
    Mild 36.02%
    Sulfury 30.43%
    Bland 29.71%
    Cooked 27.98%
    Roasted 26.82%
    Yeast 23.79%
    Very mild 23.29%
    Faint 22.46%
    Bitter 22.38%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    -3.1

    pKa est.
    5.36 (weak acid)

    Molecular weight
    179.2 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Melting point expt.

    • 185-187

    Boiling point

    • 417.3 ± 45.0

    Flash point

    • 206.57 ˚C est.

    Solubility expt.

    • 1.6g/L

  • Synonyms

    • carbocysteine
    • Carbocisteine
    • 638-23-3
    • S-Carboxymethyl-L-cysteine
    • S-(CARBOXYMETHYL)-L-CYSTEINE
    • carbocistein
    • Rhinathiol
    • Mucodyne
    • Transbronchin
    • Lisomucil
    • Muciclar
    • Mucolase
    • Reomucil
    • Mucocis
    • Siroxyl
    • Carbocisteina
    • Carbocit
    • Mucofan
    • Mucolex
    • Mucopront
    • l-carbocysteine
    • Pectox
    • L-Carbocisteine
    • (R)-S-(Carboxymethyl)cysteine
    • Carbocisteinum
    • Methista
    • Pulmoclase
    • S-(Carboxymethyl)-(R)-cysteine
    • L-3-((Carboxymethyl)thio)alanine
    • (L)-2-Amino-3-(carboxymethylthio)propionic acid
    • L-Cysteine, S-(carboxymethyl)-
    • (2R)-2-amino-3-[(carboxymethyl)sulfanyl]propanoic acid
    • AHR-3053
    • LJ 206
    • LJ-206
    • R05CB03
    • 740J2QX53R
    • LJ206
    • NSC-14156
    • Mucodine
    • CHEBI:16163
    • DTXSID30110060
    • Cysteine, S-(carboxymethyl)-
    • (2R)-2-azanyl-3-(2-hydroxy-2-oxoethylsulfanyl)propanoic acid
    • NSC-68427
    • L-Isomer Carbocysteine
    • S Carboxymethylcysteine
    • DTXCID702738
    • (2R)-2-amino-3-((carboxymethyl)sulfanyl)propanoic acid
    • Mucodyne fte
    • Carbocysteine, L
    • Carbocysteine, L-
    • RefChem:5649
    • DTXCID3065320
    • (2R)-2-Amino-3-carboxymethylsulfanylpropanoic acid
    • 211-327-5
    • 2-amino-3-(carboxymethylsulfanyl)propanoic acid
    • 3-(Carboxymethylthio)alanine
    • DTXSID9022738
    • Loviscol
    • Lisil
    • Bronchokod
    • Rinatiol
    • Mucotab
    • H-Cys(carboxymethyl)-OH
    • Thiodril
    • MFCD00002614
    • 186537-58-6
    • Carbocisteine [INN]
    • 3-(Carboxymethylthio)-L-alanine
    • (2R)-2-amino-3-(carboxymethylsulfanyl)propanoic acid
    • AHR 3053
    • (R)-2-Amino-3-((carboxymethyl)thio)propanoic acid
    • CHEMBL396416
    • 1391068-19-1
    • Carboxymethylcysteine
    • (2R)-2-Amino-3-[(carboxymethyl)thio]propionic acid
    • Carbocysteine [USAN]
    • Alanine, 3-((carboxymethyl)thio)-, L-
    • Chilvax
    • Mucosol
    • Mucotron
    • PectDrill
    • S-Carboxylmethyl-L-cysteine
    • (2R)-2-amino-3-(carboxymethylthio)propanoic acid
    • 3-[(Carboxymethyl)thio]alanine
    • Mukinyl
    • 3-((Carboxymethyl)thio)-L-alanine
    • Mucojet sirup
    • Mucolex sirup
    • Superthiol sirup
    • L-(Carboxymethyl)cysteine
    • SCMC
    • Carbocisteinum [INN-Latin]
    • (2R)-2-AMINO-3-((CARBOXYMETHYL)THIO)PROPIONIC ACID
    • Carbocisteina [INN-Spanish]
    • Car bocisteine
    • Carbocysteine;
    • UNII-740J2QX53R
    • Actithiol;
    • Mucodyne;
    • Thiodril;
    • Carbocysteine [USAN:INN:BAN]
    • L.J.206
    • Carbocisteine CRS
    • Mucodyne (TN)
    • DF 1794Y
    • EINECS 211-327-5
    • Carbocistein [JAN]
    • NSC 14156
    • Carbocysteine dl-form
    • BRN 1725012
    • L.J. 206
    • Carbocisteine (Standard)
    • Carbocysteine/Carbocisteine
    • CARBOCYSTEINE [MI]
    • L-Carbocisteine (JP18)
    • CARBOCISTEINE [JAN]
    • SCHEMBL20854
    • CARBOCISTEINE [MART.]
    • L-CARBOCISTEINE [JAN]
    • L-Cysteine, S-carboxymethyl-
    • HY-D0205AR
    • orb1304000
    • HY-D0205A
    • (Carboxymethyl)cysteine-, (L)-
    • L-CARBOCISTEINE [WHO-DD]
    • 638-23-3

  • Applications

    Carbocysteine (CAS 638-23-3) is used as a building block and intermediate in the synthesis of cysteine-derived compounds and other sulfur-containing derivatives for the chemical industry. It commonly serves as an intermediate in the production of pharmaceutical precursors and other thiol-containing specialty chemicals, while providing a functional thiol group for subsequent transformations and disulfide-formation steps in synthetic routes. Its carboxyl and thiol functionality also makes it a relevant starting material for polymer-related applications, including crosslinking and surface modification chemistries, as well as for metal-binding contexts in formulations, subject to regulatory requirements.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 0.26
    methanol 1.65
    isopropanol 0.1
    water 83.05
    ethyl acetate 0.06
    n-propanol 0.14
    acetone 0.42
    n-butanol 0.08
    acetonitrile 0.04
    DMF 4.36
    toluene 0.05
    isobutanol 0.08
    1,4-dioxane 0.2
    methyl acetate 0.06
    THF 0.28
    2-butanone 0.12
    n-pentanol 0.06
    sec-butanol 0.08
    n-hexane 0.03
    ethylene glycol 9.89
    NMP 16.07
    cyclohexane 0.05
    DMSO 33.96
    n-butyl acetate 0.11
    n-octanol 0.09
    chloroform 0.01
    n-propyl acetate 0.04
    acetic acid 2.95
    dichloromethane 0.02
    cyclohexanone 0.38
    propylene glycol 2.42
    isopropyl acetate 0.06
    DMAc 5.12
    2-ethoxyethanol 0.92
    isopentanol 0.09
    n-heptane 0.08
    ethyl formate 0.19
    1,2-dichloroethane 0.03
    n-hexanol 0.19
    2-methoxyethanol 3.25
    isobutyl acetate 0.02
    tetrachloromethane 0.04
    n-pentyl acetate 0.07
    transcutol 1.65
    n-heptanol 0.17
    ethylbenzene 0.04
    MIBK 0.15
    2-propoxyethanol 1.25
    tert-butanol 0.35
    MTBE 0.05
    2-butoxyethanol 0.7
    propionic acid 0.55
    o-xylene 0.15
    formic acid 37.35
    diethyl ether 0.04
    m-xylene 0.09
    p-xylene 0.05
    chlorobenzene 0.01
    dimethyl carbonate 0.27
    n-octane 0.02
    formamide 19.56
    cyclopentanone 0.55
    2-pentanone 0.14
    anisole 0.07
    cyclopentyl methyl ether 0.23
    gamma-butyrolactone 0.79
    1-methoxy-2-propanol 1.29
    pyridine 0.1
    3-pentanone 0.15
    furfural 1.88
    n-dodecane 0.01
    diethylene glycol 5.82
    diisopropyl ether 0.05
    tert-amyl alcohol 0.28
    acetylacetone 0.6
    n-hexadecane 0.01
    acetophenone 0.19
    methyl propionate 0.14
    isopentyl acetate 0.1
    trichloroethylene 0.04
    n-nonanol 0.1
    cyclohexanol 0.17
    benzyl alcohol 0.14
    2-ethylhexanol 0.15
    isooctanol 0.12
    dipropyl ether 0.13
    1,2-dichlorobenzene 0.03
    ethyl lactate 0.34
    propylene carbonate 0.37
    n-methylformamide 2.53
    2-pentanol 0.06
    n-pentane 0.02
    1-propoxy-2-propanol 0.8
    1-methoxy-2-propyl acetate 0.43
    2-(2-methoxypropoxy) propanol 1.26
    mesitylene 0.13
    ε-caprolactone 0.32
    p-cymene 0.13
    epichlorohydrin 0.16
    1,1,1-trichloroethane 0.02
    2-aminoethanol 3.86
    morpholine-4-carbaldehyde 5.38
    sulfolane 10.14
    2,2,4-trimethylpentane 0.02
    2-methyltetrahydrofuran 0.12
    n-hexyl acetate 0.09
    isooctane 0.02
    2-(2-butoxyethoxy)ethanol 1.28
    sec-butyl acetate 0.03
    tert-butyl acetate 0.19
    decalin 0.03
    glycerin 18.3
    diglyme 1.8
    acrylic acid 1.51
    isopropyl myristate 0.06
    n-butyric acid 0.31
    acetyl acetate 0.13
    di(2-ethylhexyl) phthalate 0.2
    ethyl propionate 0.07
    nitromethane 1.84
    1,2-diethoxyethane 0.1
    benzonitrile 0.04
    trioctyl phosphate 0.16
    1-bromopropane 0.01
    gamma-valerolactone 1.76
    n-decanol 0.08
    triethyl phosphate 0.25
    4-methyl-2-pentanol 0.08
    propionitrile 0.03
    vinylene carbonate 0.33
    1,1,2-trichlorotrifluoroethane 2.85
    DMS 0.17
    cumene 0.05
    2-octanol 0.08
    2-hexanone 0.08
    octyl acetate 0.08
    limonene 0.18
    1,2-dimethoxyethane 0.73
    ethyl orthosilicate 0.2
    tributyl phosphate 0.16
    diacetone alcohol 1.16
    N,N-dimethylaniline 0.21
    acrylonitrile 0.08
    aniline 0.11
    1,3-propanediol 1.54
    bromobenzene 0.01
    dibromomethane 0.01
    1,1,2,2-tetrachloroethane 0.06
    2-methyl-cyclohexyl acetate 0.18
    tetrabutyl urea 0.41
    diisobutyl methanol 0.16
    2-phenylethanol 0.22
    styrene 0.03
    dioctyl adipate 0.12
    dimethyl sulfate 1.82
    ethyl butyrate 0.13
    methyl lactate 1.3
    butyl lactate 0.38
    diethyl carbonate 0.09
    propanediol butyl ether 1.07
    triethyl orthoformate 0.18
    p-tert-butyltoluene 0.14
    methyl 4-tert-butylbenzoate 0.76
    morpholine 0.24
    tert-butylamine 0.13
    n-dodecanol 0.07
    dimethoxymethane 0.94
    ethylene carbonate 0.19
    cyrene 3.17
    2-ethoxyethyl acetate 0.15
    2-ethylhexyl acetate 0.08
    1,2,4-trichlorobenzene 0.04
    4-methylpyridine 0.08
    dibutyl ether 0.04
    2,6-dimethyl-4-heptanol 0.16
    DEF 0.57
    dimethyl isosorbide 2.4
    tetrachloroethylene 0.14
    eugenol 0.86
    triacetin 0.33
    span 80 1.06
    1,4-butanediol 0.59
    1,1-dichloroethane 0.01
    2-methyl-1-pentanol 0.07
    methyl formate 1.76
    2-methyl-1-butanol 0.08
    n-decane 0.02
    butyronitrile 0.02
    3,7-dimethyl-1-octanol 0.08
    1-chlorooctane 0.02
    1-chlorotetradecane 0.01
    n-nonane 0.02
    undecane 0.01
    tert-butylcyclohexane 0.02
    cyclooctane 0.05
    cyclopentanol 0.22
    tetrahydropyran 0.06
    tert-amyl methyl ether 0.1
    2,5,8-trioxanonane 2.19
    1-hexene 0.03
    2-isopropoxyethanol 0.34
    2,2,2-trifluoroethanol 2.92
    methyl butyrate 0.1

    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