Tetraethoxymethane Explained

Tetraethoxymethane is a chemical compound which is formally formed by complete ethylation of the hypothetical orthocarbonic acid C(OH)₄ (orthocarbonic acid violates the Erlenmeyer rule and is unstable in free state).

History

Tetraethoxymethane was described the first time in 1864.^[1]

Synthesis

The preparation of tetraethoxymethane from the highly toxic trichloronitromethane is known in the literature^{[1] [2] [3]} and achieves only yields of 46-49 to 58%:^[3]

The obvious synthetic route from tetrachloromethane does not provide the desired product, as in the homologous tetramethoxymethane.^[4]

Starting from the less toxic trichloroacetonitrile (compared with trichloronitromethane), higher yields can be obtained (up to 85%).^[5] An alternative reaction, bypassing problematic reactants, is the reaction of dialkyltin dialkoxides with carbon disulfide at elevated temperature in an autoclave:^[6]

Another route reacts thallous ethoxide with carbon disulfide in dry methylene dichloride.^[7]

A more recent synthesis starts directly from sodium ethoxide, tin(IV)chloride, and carbon disulfide.^[8]

Properties

Tetraethoxymethane is a water-clear, aromatic or fruity smelling,^[9] liquid of low-viscosity which is unstable against strong acids and strong bases.

Uses

Tetraethoxymethane can be used as a solvent and for the alkylation of CH-acidic compounds (e.g. phenols and carboxylic acids). In addition, it reacts with amines, enol ethers and sulfonamides,^[10] whereby spiro compounds can also be obtained. Spiro orthocarbonates (SOCs)^[11] are of some industrial interest, as they are used as additives for reducing shrinkage during the polymerization of epoxides (they are used as expanding monomers).^[12]

References

1. H. Bassett, Ueber das vierfach-basische kohlensaure Aethyl, Ann. 132, 54 (1864), .
2. H. Tieckelmann, H.W. Post, The preparation of methyl, ethyl, propyl, and butyl orthocarbonates, J. Org. Chem., 13 (2), 265–267 (1948), .
3. Europäische Patentschrift EP 0881212 B1, Production method of aminobenzene compound, Erfinder: H. Hashimoto et al., Anmelder: Takeda Chemical Industries, Ltd., veröffentlicht am 30. Oktober 2001.
4. R.H. De Wolfe, Carboxylic ortho acid derivatives: preparation and synthetic applications, Organic Chemistry, Vol. 14, Academic Press, Inc. New York – London, 1970, .
5. US-Patent US 6825385, Process for the preparation of orthocarbonates, Erfinder: G. Fries, J. Kirchhoff, Anmelder: Degussa AG, erteilt am 30. November 2004.
6. S. Sakai et al., Reaction of Dialkyltin Dialkoxides with Carbon Disulfide at Higher Temperature. Preparation of Orthocarbonates, J. Org. Chem., 36 (9), 1176 (1971), .
7. Shizuyoshi Sakai, Yoshitaka Kuroda, Yoshio Ishii (1972): "Preparation of orthocarbonates from thallous alkoxides and carbon disulfide". Journal of Organic Chemistry, volume 37, issue 25, pages 4198–4200.
8. S. Sakai et al., A new method for preparation of tetraalkyl orthocarbonates from sodium alkoxides, tetrachlorostannane, and carbon disulfide, Synthesis 1984 (3), 233–234, .
9. J. H. Ruth, Odor Thresholds and Irritation Levels of Several Chemical Substances: A Review, Am. Ind. Hyg. Assoc. J. 47, A-142 – A-151, (1986).
10. W. Kantlehner et al., Die präparative Chemie der O- und N-funktionellen Orthokohlensäure-Derivate, Synthesis, 1977, 73–90.
11. Vodak . David T. . Braun . Matthew . Iordanidis . Lykourgos . Plévert . Jacques . Stevens . Michael . Beck . Larry . Spence . John C. H. . O'Keeffe . Michael . Yaghi . Omar M. . One-Step Synthesis and Structure of an Oligo(spiro-orthocarbonate) . Journal of the American Chemical Society . American Chemical Society (ACS) . 124 . 18 . 2002-04-11 . 0002-7863 . 10.1021/ja017683i . 4942–4943. 11982342 .
12. R. Acosta Ortiz et al., Novel diol spiro orthocarbonates derived from glycerol as anti-shrinkage additives for the cationic photopolymerization of epoxy monomers, Polymer International, 59(5), 680–685 (2010), .