Tetramethoxymethane
Chemical compound
From Wikipedia, the free encyclopedia
Tetramethoxymethane is a chemical compound which is formally formed by complete methylation of the hypothetical orthocarbonic acid C(OH)4.
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| Names | |
|---|---|
| Preferred IUPAC name
Tetramethoxymethane | |
| Other names
Tetramethyl orthocarbonate | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.015.853 |
| EC Number |
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PubChem CID |
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| UNII | |
| UN number | 3272 |
CompTox Dashboard (EPA) |
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| Properties | |
| C5H12O4 | |
| Molar mass | 136.15 g·mol−1 |
| Appearance | colourless liquid[1] |
| Density | 1.023 g/cm3 (25 °C) |
| Melting point | −5.5 °C[1] |
| Boiling point | 114 °C[1] |
| Hazards | |
| GHS labelling: | |
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| Danger | |
| H225, H315, H319, H335 | |
| P210, P261, P305+P351+P338 | |
| Related compounds | |
Other cations |
Tetramethoxysilane |
Related compounds |
Tetraethoxymethane |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation
The obvious synthetic route from the tetrahalomethanes does not yield the desired product, instead giving orthoformates and a halohydrin byproduct.[2]: 13 The original preparation of the tetramethoxymethane was therefore based on chloropicrin:[1]
Because of the extreme toxicity of chloropicrin, other tetrasubstituted reactive methane derivatives were investigated as starting material for tetramethoxymethane. For example, trichloromethanesulfenyl chloride (also used as a chemical warfare agent and easily accessible from carbon disulfide and chlorine) was used:[3][4]
A less problematic synthesis is based on trichloroacetonitrile:[5][6]
Thallium methoxide reacts with carbon disulfide to give tetramethoxymethane and thallium sulfide;[7] likewise dimethyl dibutylstannate gives tetramethoxymethane and dibutyltin sulfide.[8] Further preparative methods are described in the literature.[7]
Synthesis from chloropicrin only yields about 50% product. Syntheses from trichloromethanesulfenyl chloride or trichloroacetonitrile or the thallium-sulfide route yield about 70-80% product,[3][7] but the tin-sulfide synthesis has a 95% yield.[8]
Properties
Tetramethoxymethane is a clear, colorless, aromatic-smelling, low-viscosity liquid which is stable against peroxide formation.[9]
Use
In addition to its use as a solvent, tetramethoxymethane is also used as a fuel in polymer fuel cells,[10] as an alkylating agent at elevated temperatures (180-200 °C),[11] as a transesterification reagent (but showing less reactivity than trimethoxymethane[2]), and as a reagent for the synthesis of 2-aminobenzoxazoles, which are used as molecular building blocks in pharmaceutical active ingredients used in neuroleptics, sedatives, antiemetics, muscle relaxants, fungicides and others.[12]
Depending on the substituents, the one pot reaction proceeds in "modest to excellent" yields.