Dimethyl tellurium dichloride

Tellurium-induced demyelination seems to be a result of squalene monooxygenase inhibition, and dimethyl tellurium dichloride may be the neurotoxic species presented to Schwann cells in vivo. 

Dimethyl tellurium diiodide was treated with concentrated ammonia, then with silver nitrate to precipitate silver iodide, and finally with hydrochloric or hydrobromic acid to give dimethyl tellurium dichloride or dibromide4. 

Dimethyl Tellurium Dichloride4 Concentrated ammonia is added to dimethyl tellurium diiodide, and the grey paste that is formed is separated, and dissolved in water. A solution of silver nitrate is added until no more silver iodide precipitates. The silver halide is filtered off, hydrochloric acid is added to the filtrate, and the white precipitate of dimethyl tellurium dichloride is collected m.p. 95°. 

Dimethyl tellurium dichloride, diphenyl tellurium dichloride and heterocyclic tellurium diiodides reacted with sodium tetraphenylborate in methanol or ethanol to produce telluronium tetraphenylborates5. 

Diaryl tellurium dihalides condense with 5,5-dimethyl-l, 3-dioxocyclohexane in benzene in the presence of triethylamine to give cyclohexylidene diaryl tellurium compounds. Whether a reaction occurs at 20° or requires elevated temperatures is determined by the substituents on the aryl groups. Dimethyl tellurium dichloride and aryl methyl tellurium dichlorides react at 20°. 

Excess methyl trimethylsilyl tellurium with dimethyl germyl dichloride produced dimeth-ylgermylene bis [methyl tellurium] in 89% yield. Use of equimolar amounts of the reactants formed mainly dimethyl(chloro)germyl methyl tellurium2. 

Dimethyl-2-oxo-butyl 4-methoxyphenyl tellurium dichloride decomposed at 210730 torr to bis[4-methoxyphenyl ditellurium and l-chloro-3,3-dimethyl-2-oxobutane3. 

Evaporation of a solution of equimolar amounts of diphenyl tellurium dibromide and mercury(II) chloride in ethanol and extraction of the residue with hot chloroform gave diphenyl tellurium dichloride (m.p. 160°) in high yield. A similar reaction in chloroform converted dimethyl tellurium diiodide to the dichloride (m.p. 90°) in 95% yield3. 

Diphenyl Tellurium Diperchlorate/Dimethyl Sulfoxide Complex1 A mixture of 0.70 g (2 mmol) diphenyl tellurium dichloride, 0.83 g (4 mmol) silver perchlorate and 30 ml dichloromethane is stirred at 20° for 1 h. The precipitated silver chloride is removed by filtration. The filtrate is mixed with a solution of 0.15 g (2 mmol) dimethyl sulfoxide in 10 m/ dichloromethane. The mixture is refluxed for 5h. The solvent is distilled from the mixture. The residue is treated with petroleum ether (40 - 60°). The resulting white solid is recrystallized from petroleum ether (40-60°)/dichloromethane (3 1) and then dried under reduced pressure 95% yield m.p. 140°. 

Diphenyl Tellurium Bis[0,0 -dimethyl dithiophosphate]1 A mixture of 0.20 g (0.57 mmol) of diphenyl tellurium dichloride and 5 ml carbon disulfide is treated with 0.25 g (1.2 mmol) dry ammonium 0,0-dimethyl dithiophosphate. The stirred mixture is refluxed for 4 h, then coolded and filtered. The filtrate is concentrated under reduced pressure to approximately 1 ml. The residue is mixed with 1 m hexane and the mixture cooled to —4° yield 62% m.p. 116° (from carbon disulfide). 

Dimethyl-2-oxo-l-butyl 4-Methoxyphenyl Tellurium Dichloride A suspension of 1.02 g (3.0 mmol) of 4-methoxyphenyl tellurium trichloride in 10 m/ benzene is mixed with 0.516 g (3.0 mmol) 3,3-dimethyl-2-trimethylsiloxybut-l-ene. The mixture is refluxed for 10 h, then treated with 100 ml methanol/water (1 1), and extracted with chloroform. The organic phase is separated, dried with anhydrous magnesium sulfate, filtered, and the filtrate evaporated. The residue is chromatographed on silica gel with chloroform as the mobile phase. The product is recrystallized from chloroform/petroleum ether (30-60°) yield 80% m.p. 90-92°. 

The 1,4-oxateIIurin-7e,7h-dichloride and 5,5-dimethyl-l,3-dioxocyclohexane condensed to form a tellurium ylide ... 

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