Cytosine

Overview IFRA Request a quote

  • Identifiers

    CAS number
    71-30-7

    Molecular formula
    C4H5N3O

    SMILES
    C1=C(NC(=O)N=C1)N

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Odorless 57.2%
    Burnt 30.9%
    Nutty 27.75%
    Meaty 27.69%
    Roasted 27.1%
    Cooked 22.89%
    Bitter 22.76%
    Musty 20.83%
    Animal 20.14%
    Fishy 20.12%

     

    Flavor
    Bitter 64.6%
    Odorless 34.57%
    Nutty 30.03%
    Mild 25.18%
    Bread crust 22.03%
    Formyl 20.72%
    Nitrile 20.69%
    Roasted peanuts 20.62%
    Taco 20.39%
    Mold 20.22%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    -1.7

    pKa est.
    8.88 (weak base)

    Molecular weight
    111.1 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Boiling point est.
    374°C

    Melting point expt.

    • > 300 °C

    Flash point

    • 205.68 ˚C est.

    Solubility expt.

    • 8.0 mg/mL
    • >16.7 [ug/mL] (The mean of the results at pH 7.4)

  • Synonyms

    • cytosine
    • 71-30-7
    • 4-Amino-2-hydroxypyrimidine
    • 4-aminopyrimidin-2(1H)-one
    • Cytosinimine
    • 2(1H)-Pyrimidinone, 4-amino-
    • 4-Amino-2(1H)-pyrimidinone
    • 6-amino-1H-pyrimidin-2-one
    • DTXSID4044456
    • NSC-27787
    • 8J337D1HZY
    • CHEBI:16040
    • 4-amino-3h-pyrimidin-2-one
    • DTXCID2024456
    • NSC27787
    • 6-amino-1,2-dihydropyrimidin-2-one
    • RefChem:5728
    • 200-749-5
    • 4-Aminouracil
    • 6-Aminopyrimidin-2(1h)-One
    • MFCD00006034
    • 4-aminopyrimidin-2-ol
    • Cytosin
    • 2(1H)-pyrimidinone, 6-amino-
    • Cyt
    • 4-amino-2-oxo-1,2-dihydropyrimidine
    • 4-amino-2-pyrimidinol
    • Zytosin
    • AI3-52281
    • 107646-83-3
    • 134434-40-5
    • 107646-84-4
    • 134434-39-2
    • 2(1H)-Pyrimidinone, 3,4-dihydro-4-imino-, (E)- (9CI)
    • 4-Aminopyrimidin-2-(1H)-one
    • 2(1H)-Pyrimidinone, 3,4-dihydro-4-imino-, (Z)- (9CI)
    • 4-Aminopyrimidin-2(1H)-one (Cytosine)
    • Cytosine-5,6-d2
    • 6-amino-3-hydropyrimidin-2-one
    • pyrimidine, 4-amino-2-hydroxy-
    • 4-Amino-1H-pyrimidin-2-one
    • SMR000857094
    • EINECS 200-749-5
    • Lamivudine EP Impurity E
    • 4-amino-1,2-dihydropyrimidin-2-one
    • NSC 27787
    • 2-Pyrimidinol, 1,4-dihydro-4-imino-
    • aminopyrimidone
    • UNII-8J337D1HZY
    • iminopyrimidinone
    • 3h-cytosine
    • 66460-18-2
    • 66460-21-7
    • Cytosine (8CI)
    • Cytosine (Standard)
    • Lamivudine impurity c
    • 2-Pyrimidinol, 1,4-dihydro-4-imino-, (Z)- (9CI)
    • 106391-24-6
    • Cytosine, >=99%
    • 2(1H)-Pyrimidinone, 4-amino- (9CI)
    • Lamivudine impurity c rs
    • CYTOSINE [MI]
    • 4-amino-pyrimidin-2-ol
    • 4-Amino-2-oxypyrimidine
    • 2(1H)-Pyrimidinone, 3,4-dihydro-4-imino-
    • bmse000180
    • CYTOSINE [USP-RS]
    • CYTOSINE [WHO-DD]
    • Epitope ID:167475
    • 4-Amino-2(1H)pyrimidone
    • EC 200-749-5
    • Gemcitabine impurity A CRS
    • SCHEMBL4059
    • SCHEMBL8618
    • 4-Amino-2(1H)-pyrimidone
    • 2-Hydroxy-6-amino-pyrimidin
    • MLS001332635
    • MLS001332636
    • CHEMBL15913
    • SCHEMBL308339
    • SCHEMBL437958
    • SCHEMBL437959
    • SCHEMBL655341
    • 2-Pyrimidinol, 1,6-dihydro-6-imino-, (E)- (9CI)
    • GTPL8490
    • orb1302527
    • SCHEMBL4818561
    • SCHEMBL6547006
    • SCHEMBL8921275
    • SCHEMBL10402537
    • HY-I0626R
    • MSK6920
    • HMS2233N21
    • HMS3369N05
    • HMS5083D22
    • Cytosine, >=99.0% (HPLC)
    • ALBB-021996
    • HY-I0626
    • STR01426
    • Tox21_302139
    • EBC-06142
    • EBC-44129
    • s4893
    • SBB071711
    • STK366767
    • STL455080
    • AKOS000120336
    • AKOS005443393
    • AKOS015896942
    • AC-2489
    • CCG-266052
    • CS-W020703
    • FC03781
    • 2-Pyrimidinol, 1,6-dihydro-6-imino-
    • CAS-71-30-7
    • CID 5274263
    • SRI-2354-05
    • NCGC00247019-01
    • NCGC00255926-01
    • 66398-98-9
    • 66460-19-3
    • BP-20183
    • Cytosine, Vetec(TM) reagent grade, 99%
    • NCI60_012445
    • SY001643
    • 4-imino-3,4-dihydropyrimidin-2(1H)-one
    • DB-029615
    • 71-30-7

  • Applications

    Cytosine (CAS 71-30-7) is a natural pyrimidine base primarily used as an intermediate in the synthesis of nucleosides and nucleoside derivatives for pharmaceutical applications; in laboratory settings it serves as a reagent for biochemical research and the synthesis of nucleic acids and oligonucleotides, and can also function as a building block for nucleic acid-based polymers or related biobased materials; additionally, Cytosine acts as a precursor for the production of cytidine and related nucleoside derivatives in the pharmaceutical industry, with applications subject to local regulations.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 0.55
    methanol 1.75
    isopropanol 0.24
    water 7.34
    ethyl acetate 0.21
    n-propanol 0.36
    acetone 0.39
    n-butanol 0.25
    acetonitrile 0.26
    DMF 19.63
    toluene 0.02
    isobutanol 0.2
    1,4-dioxane 0.31
    methyl acetate 0.35
    THF 1.61
    2-butanone 0.31
    n-pentanol 0.21
    sec-butanol 0.18
    n-hexane 0.01
    ethylene glycol 3.94
    NMP 22.89
    cyclohexane 0.0
    DMSO 15.42
    n-butyl acetate 0.37
    n-octanol 0.09
    chloroform 0.03
    n-propyl acetate 0.29
    acetic acid 3.53
    dichloromethane 0.04
    cyclohexanone 0.57
    propylene glycol 3.77
    isopropyl acetate 0.17
    DMAc 19.33
    2-ethoxyethanol 2.26
    isopentanol 0.24
    n-heptane 0.01
    ethyl formate 0.67
    1,2-dichloroethane 0.03
    n-hexanol 0.18
    2-methoxyethanol 5.73
    isobutyl acetate 0.2
    tetrachloromethane 0.02
    n-pentyl acetate 0.22
    transcutol 2.99
    n-heptanol 0.16
    ethylbenzene 0.02
    MIBK 0.24
    2-propoxyethanol 2.65
    tert-butanol 0.27
    MTBE 0.07
    2-butoxyethanol 1.79
    propionic acid 1.58
    o-xylene 0.04
    formic acid 10.55
    diethyl ether 0.05
    m-xylene 0.04
    p-xylene 0.04
    chlorobenzene 0.03
    dimethyl carbonate 1.14
    n-octane 0.0
    formamide 9.12
    cyclopentanone 1.56
    2-pentanone 0.25
    anisole 0.11
    cyclopentyl methyl ether 0.3
    gamma-butyrolactone 3.87
    1-methoxy-2-propanol 3.71
    pyridine 0.28
    3-pentanone 0.19
    furfural 4.68
    n-dodecane 0.0
    diethylene glycol 6.56
    diisopropyl ether 0.02
    tert-amyl alcohol 0.24
    acetylacetone 0.62
    n-hexadecane 0.0
    acetophenone 0.33
    methyl propionate 0.61
    isopentyl acetate 0.39
    trichloroethylene 0.08
    n-nonanol 0.09
    cyclohexanol 0.15
    benzyl alcohol 0.29
    2-ethylhexanol 0.14
    isooctanol 0.15
    dipropyl ether 0.17
    1,2-dichlorobenzene 0.04
    ethyl lactate 1.43
    propylene carbonate 2.12
    n-methylformamide 5.58
    2-pentanol 0.11
    n-pentane 0.01
    1-propoxy-2-propanol 1.74
    1-methoxy-2-propyl acetate 1.16
    2-(2-methoxypropoxy) propanol 2.72
    mesitylene 0.04
    ε-caprolactone 0.97
    p-cymene 0.06
    epichlorohydrin 0.88
    1,1,1-trichloroethane 0.04
    2-aminoethanol 3.6
    morpholine-4-carbaldehyde 11.94
    sulfolane 11.19
    2,2,4-trimethylpentane 0.01
    2-methyltetrahydrofuran 0.36
    n-hexyl acetate 0.2
    isooctane 0.0
    2-(2-butoxyethoxy)ethanol 2.45
    sec-butyl acetate 0.15
    tert-butyl acetate 0.27
    decalin 0.0
    glycerin 13.32
    diglyme 4.35
    acrylic acid 2.98
    isopropyl myristate 0.11
    n-butyric acid 1.1
    acetyl acetate 0.24
    di(2-ethylhexyl) phthalate 0.55
    ethyl propionate 0.31
    nitromethane 4.95
    1,2-diethoxyethane 0.23
    benzonitrile 0.22
    trioctyl phosphate 0.3
    1-bromopropane 0.02
    gamma-valerolactone 5.18
    n-decanol 0.07
    triethyl phosphate 0.54
    4-methyl-2-pentanol 0.12
    propionitrile 0.2
    vinylene carbonate 1.73
    1,1,2-trichlorotrifluoroethane 4.63
    DMS 0.48
    cumene 0.03
    2-octanol 0.07
    2-hexanone 0.26
    octyl acetate 0.16
    limonene 0.07
    1,2-dimethoxyethane 2.24
    ethyl orthosilicate 0.41
    tributyl phosphate 0.38
    diacetone alcohol 1.36
    N,N-dimethylaniline 0.21
    acrylonitrile 0.52
    aniline 0.15
    1,3-propanediol 2.28
    bromobenzene 0.01
    dibromomethane 0.02
    1,1,2,2-tetrachloroethane 0.09
    2-methyl-cyclohexyl acetate 0.39
    tetrabutyl urea 0.65
    diisobutyl methanol 0.13
    2-phenylethanol 0.29
    styrene 0.02
    dioctyl adipate 0.34
    dimethyl sulfate 4.79
    ethyl butyrate 0.42
    methyl lactate 3.84
    butyl lactate 1.1
    diethyl carbonate 0.43
    propanediol butyl ether 2.28
    triethyl orthoformate 0.48
    p-tert-butyltoluene 0.06
    methyl 4-tert-butylbenzoate 1.1
    morpholine 0.82
    tert-butylamine 0.09
    n-dodecanol 0.06
    dimethoxymethane 2.52
    ethylene carbonate 1.08
    cyrene 5.17
    2-ethoxyethyl acetate 0.49
    2-ethylhexyl acetate 0.28
    1,2,4-trichlorobenzene 0.08
    4-methylpyridine 0.28
    dibutyl ether 0.06
    2,6-dimethyl-4-heptanol 0.13
    DEF 1.18
    dimethyl isosorbide 4.29
    tetrachloroethylene 0.07
    eugenol 1.71
    triacetin 0.75
    span 80 1.63
    1,4-butanediol 1.25
    1,1-dichloroethane 0.02
    2-methyl-1-pentanol 0.2
    methyl formate 3.41
    2-methyl-1-butanol 0.23
    n-decane 0.0
    butyronitrile 0.19
    3,7-dimethyl-1-octanol 0.11
    1-chlorooctane 0.01
    1-chlorotetradecane 0.01
    n-nonane 0.0
    undecane 0.0
    tert-butylcyclohexane 0.01
    cyclooctane 0.0
    cyclopentanol 0.41
    tetrahydropyran 0.1
    tert-amyl methyl ether 0.1
    2,5,8-trioxanonane 4.03
    1-hexene 0.03
    2-isopropoxyethanol 1.01
    2,2,2-trifluoroethanol 3.18
    methyl butyrate 0.53

    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