Trimethyl orthoformate

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  • Identifiers

    CAS number
    149-73-5

    Molecular formula
    C4H10O3

    SMILES
    COC(OC)OC

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Ethereal 77.79%
    Fruity 51.78%
    Alcoholic 46.91%
    Fresh 42.77%
    Sweet 34.27%
    Rummy 34.17%
    Sharp 33.0%
    Fermented 31.09%
    Cognac 29.62%
    Winey 28.21%

     

    Flavor
    Green 65.76%
    Sweet 61.57%
    Ether 44.38%
    Bitter 40.04%
    Fruity 38.32%
    Alcoholic 36.51%
    Sharp 35.88%
    Earthy 35.74%
    Alcohol 33.68%
    Vegetable 33.41%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    0.2

    pKa est.
    6.85 (neutral)

    Molecular weight
    106.12 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Boiling point

    • 100.6 °C @ 760 MM HG

    Flash point

    • -0.26 ˚C est.

    Solubility expt.

    • SOL IN ETHANOL, IN ETHER

  • Synonyms

    • Trimethoxymethane
    • TRIMETHYL ORTHOFORMATE
    • 149-73-5
    • Methyl orthoformate
    • Methane, trimethoxy-
    • Orthoformic acid methyl ester
    • Orthoformic acid, trimethyl ester
    • Methoxymethylal
    • Orthomravencan methylnaty
    • Methylester kyseliny orthomravenci
    • NSC 147479
    • Orthoformic acid trimethyl ester
    • HSDB 1006
    • Orthomravencan methylnaty [Czech]
    • trimethoxy-methane
    • Trimethylester kyseliny orthomravenci
    • EINECS 205-745-7
    • BRN 0969215
    • XAM28819YJ
    • DTXSID7027122
    • Methylester kyseliny orthomravenci [Czech]
    • AI3-23842
    • PERMA-FLO OF
    • Trimethylester kyseliny orthomravenci [Czech]
    • NSC-147479
    • CH(OCH3)3
    • DTXCID307122
    • EC 205-745-7
    • 4-02-00-00022 (Beilstein Handbook Reference)
    • TRIMETHYL ORTHOFORMATE [HSDB]
    • MFCD00008483
    • ORTHOFORMIC ACID TRIMETHYL ESTER [MI]
    • ORTHOMRAVENCAN METHYLNATY (CZECH)
    • trimethyl ortho formate
    • METHYLESTER KYSELINY ORTHOMRAVENCI (CZECH)
    • Orthoformic acid trimethyl
    • UNII-XAM28819YJ
    • trimethoxy methane
    • trimethylorthoformat
    • Methane, trimethoxy
    • Methoxymethylal; Methyl Orthoformate; NSC 147479; Orthoformic Acid Methyl Ester; Perma-Flo OF; Trimethoxymethane
    • trimethylorthoformate
    • trimetyl orthoformate
    • trirnethylorthoformate
    • trimethyl-orthoformate
    • trimethylortho-formate
    • tri-methyl orthoformate
    • trim ethyl orthoformate
    • trimethyl ortho-formate
    • trimethyl-ortho-formate
    • (MeO)3CH
    • CH(OMe)3
    • HC(OMe)3
    • SCHEMBL6919
    • Trimethyl orthoformate, 99%
    • (CH3O)3CH
    • HC(OCH3)3
    • ortho-formic acid trimethylester
    • CHEMBL3187679
    • WLN: 1OYO1 & O1
    • ortho-formic acid trimethyl ester
    • PYOKUURKVVELLB-UHFFFAOYSA-
    • Tox21_200062
    • NSC147479
    • STL185659
    • AKOS000121043
    • NCGC00248510-01
    • NCGC00257616-01
    • BP-21313
    • CAS-149-73-5
    • LS-13013
    • Trimethyl orthoformate, anhydrous, 99.8%
    • NS00005988
    • O0068
    • EN300-21653
    • A808947
    • Q408190
    • F0001-0529
    • InChI=1/C4H10O3/c1-5-4(6-2)7-3/h4H,1-3H3
    • 205-745-7

  • Applications

    Trimethyl orthoformate (CAS 149-73-5) is primarily used in organic synthesis as a methoxymethylating agent and acetal-forming reagent. It enables installation of the methoxymethyl (MOM) protecting group on alcohols and amines under acid catalysis, supporting selective sequences in pharmaceuticals, fine chemicals, and polymer-related materials. It also serves as a convenient reagent for preparing acetals/ketals from aldehydes and ketones, thereby protecting carbonyl functionalities during multistep syntheses. In addition, it can function as a dehydrating solvent or reactant and as an intermediate in the preparation of pharmaceutical and specialty chemical intermediates. It is commonly evaluated for organic synthesis applications, subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 5807.11
    methanol 8152.53
    isopropanol 4553.75
    water 722.6
    ethyl acetate 2890.99
    n-propanol 4131.96
    acetone 4187.97
    n-butanol 3534.36
    acetonitrile 5663.68
    DMF 4178.03
    toluene 997.91
    isobutanol 3077.62
    1,4-dioxane 3785.68
    methyl acetate 2959.89
    THF 4012.82
    2-butanone 2799.81
    n-pentanol 2061.32
    sec-butanol 3686.3
    n-hexane 585.08
    ethylene glycol 1976.88
    NMP 2466.73
    cyclohexane 1298.84
    DMSO 4172.0
    n-butyl acetate 1037.82
    n-octanol 693.75
    chloroform 9131.82
    n-propyl acetate 1387.37
    acetic acid 10301.65
    dichloromethane 8183.44
    cyclohexanone 2643.95
    propylene glycol 1708.08
    isopropyl acetate 1461.56
    DMAc 2942.79
    2-ethoxyethanol 3737.06
    isopentanol 2506.62
    n-heptane 457.54
    ethyl formate 2688.89
    1,2-dichloroethane 3829.53
    n-hexanol 1113.02
    2-methoxyethanol 6284.89
    isobutyl acetate 658.27
    tetrachloromethane 3775.21
    n-pentyl acetate 809.81
    transcutol 2278.52
    n-heptanol 722.84
    ethylbenzene 460.87
    MIBK 1005.04
    2-propoxyethanol 1799.68
    tert-butanol 4758.85
    MTBE 2989.17
    2-butoxyethanol 1357.17
    propionic acid 3586.09
    o-xylene 689.12
    formic acid 7649.58
    diethyl ether 3732.4
    m-xylene 569.54
    p-xylene 703.25
    chlorobenzene 1258.41
    dimethyl carbonate 927.01
    n-octane 188.13
    formamide 7841.11
    cyclopentanone 2716.7
    2-pentanone 2183.23
    anisole 929.43
    cyclopentyl methyl ether 2247.72
    gamma-butyrolactone 3187.09
    1-methoxy-2-propanol 3406.22
    pyridine 2869.09
    3-pentanone 1695.62
    furfural 2876.19
    n-dodecane 91.18
    diethylene glycol 1542.98
    diisopropyl ether 904.38
    tert-amyl alcohol 3791.56
    acetylacetone 1732.66
    n-hexadecane 99.77
    acetophenone 818.0
    methyl propionate 1949.46
    isopentyl acetate 806.93
    trichloroethylene 6655.39
    n-nonanol 568.82
    cyclohexanol 2964.9
    benzyl alcohol 1006.91
    2-ethylhexanol 684.8
    isooctanol 580.57
    dipropyl ether 1165.52
    1,2-dichlorobenzene 1142.42
    ethyl lactate 623.26
    propylene carbonate 1652.69
    n-methylformamide 4314.34
    2-pentanol 2412.89
    n-pentane 900.86
    1-propoxy-2-propanol 1224.65
    1-methoxy-2-propyl acetate 759.76
    2-(2-methoxypropoxy) propanol 496.94
    mesitylene 400.28
    ε-caprolactone 2225.25
    p-cymene 369.82
    epichlorohydrin 3714.68
    1,1,1-trichloroethane 4683.7
    2-aminoethanol 3148.5
    morpholine-4-carbaldehyde 2513.12
    sulfolane 2721.93
    2,2,4-trimethylpentane 377.29
    2-methyltetrahydrofuran 3712.94
    n-hexyl acetate 881.4
    isooctane 205.21
    2-(2-butoxyethoxy)ethanol 777.94
    sec-butyl acetate 846.35
    tert-butyl acetate 1350.79
    decalin 278.96
    glycerin 2227.6
    diglyme 2028.69
    acrylic acid 3265.8
    isopropyl myristate 279.68
    n-butyric acid 4423.88
    acetyl acetate 1711.05
    di(2-ethylhexyl) phthalate 237.3
    ethyl propionate 1201.37
    nitromethane 8956.58
    1,2-diethoxyethane 1248.45
    benzonitrile 1212.16
    trioctyl phosphate 211.63
    1-bromopropane 2631.57
    gamma-valerolactone 3153.55
    n-decanol 357.62
    triethyl phosphate 448.72
    4-methyl-2-pentanol 986.31
    propionitrile 3064.9
    vinylene carbonate 1630.62
    1,1,2-trichlorotrifluoroethane 3850.07
    DMS 564.24
    cumene 353.23
    2-octanol 545.69
    2-hexanone 1160.93
    octyl acetate 379.63
    limonene 596.82
    1,2-dimethoxyethane 3814.42
    ethyl orthosilicate 490.41
    tributyl phosphate 251.36
    diacetone alcohol 1466.91
    N,N-dimethylaniline 690.26
    acrylonitrile 3248.3
    aniline 1468.49
    1,3-propanediol 4052.75
    bromobenzene 1242.65
    dibromomethane 5328.21
    1,1,2,2-tetrachloroethane 5156.23
    2-methyl-cyclohexyl acetate 517.57
    tetrabutyl urea 316.02
    diisobutyl methanol 489.67
    2-phenylethanol 648.24
    styrene 579.67
    dioctyl adipate 346.93
    dimethyl sulfate 1138.28
    ethyl butyrate 987.56
    methyl lactate 916.49
    butyl lactate 549.79
    diethyl carbonate 651.22
    propanediol butyl ether 726.58
    triethyl orthoformate 712.98
    p-tert-butyltoluene 370.12
    methyl 4-tert-butylbenzoate 666.65
    morpholine 4627.7
    tert-butylamine 3386.61
    n-dodecanol 253.27
    dimethoxymethane 2787.87
    ethylene carbonate 1483.88
    cyrene 594.6
    2-ethoxyethyl acetate 839.48
    2-ethylhexyl acetate 642.51
    1,2,4-trichlorobenzene 1290.75
    4-methylpyridine 2241.37
    dibutyl ether 758.96
    2,6-dimethyl-4-heptanol 489.67
    DEF 2576.15
    dimethyl isosorbide 780.48
    tetrachloroethylene 4904.49
    eugenol 564.97
    triacetin 668.67
    span 80 476.19
    1,4-butanediol 1686.0
    1,1-dichloroethane 4545.74
    2-methyl-1-pentanol 1479.68
    methyl formate 3153.04
    2-methyl-1-butanol 2706.89
    n-decane 191.76
    butyronitrile 3392.19
    3,7-dimethyl-1-octanol 582.21
    1-chlorooctane 503.87
    1-chlorotetradecane 158.75
    n-nonane 209.68
    undecane 120.64
    tert-butylcyclohexane 263.86
    cyclooctane 407.52
    cyclopentanol 3226.65
    tetrahydropyran 3800.89
    tert-amyl methyl ether 2225.54
    2,5,8-trioxanonane 922.65
    1-hexene 1097.4
    2-isopropoxyethanol 1905.69
    2,2,2-trifluoroethanol 4095.96
    methyl butyrate 1734.88

    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