From Disodium Tellurides

Disodium telluride and chlorodi-t-butylphosphane or chlorodi-isopropylphosphane combined in toluene to produce bis[dialkylphosphano tellurium.  

Bis[di-t-butylphosphano] Tellurium Disodium telluride is prepared from 5.4 g (22 mmol) of sodium and 16.6 g (13 mmol) of tellurium and suspended in 100 of toluene. A solution of3.7g(20mmol)ofchlorodi- 

Diorganophosphano trimethylsilyl tellurium compounds rearrange in benzene solution to give the symmetrical bis[diorganophosphano] tellurium and bis[trimethylsilyl] tellurium compounds  

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The following diorgano tellurium derivatives were prepared from disodium telluride, for which the mode of synthesis is not reported, and the appropriate organic bromides in dimethylformamide as the reaction medium3 ... 

For methods to prepare acyl organo tellurium compounds from disodium telluride, carboxylic acid chlorides, and alkyl halides, see p. 500. 

H-, 3-Thiatelluroles were prepared from disodium telluride and (chloromethyl-thio)ethynes2. 

Dinitrotelluranthrene 140 has been prepared by treatment of 1,2-diiodo-4-nitrobenzene with a tellurium-copper slurry obtained in situ from disodium telluride and copper(l) iodide in A -methylpyrrolidine (NMP) (Equation 35)... 

Bis[di-t-bntylphosphano] Tellurium5 Disodium telluride is prepared from 5.4 g (22 mmol) of sodium and 16.6 g (13 mmol) of tellurium and suspended in 100 ml of toluene. A solution of 3.7 g(20 mmol) ofchlorodi-t-butylphosphane in 50 ml of toluene is added to the suspension and the mixture is stirred for 12 h. The resultant mixture is filtered and the solid is washed with toluene. The filtrate and washings are combined, the solvent is removed under reduced pressure, and the residue is recrystallized from pentane yield 32 g (80%) m.p. 77°. 

Sodium l-f-Butyl-2-formylethenetellurolates1 0.1 mol of disodium telluride is prepared from sodium and tellurium in anhydrous liquid ammonia under nitrogen. The ammonia is evaporated at 20°, the residue is cooled to — 15°, and 100 ml of pure DMF are added. To the well-stirred solution arc added 0.1 mol of the appropriate l-chloro-2-formylethene dissolved in 200 ml of DMF. The mixture is then stirred for 1 h. 

Unsymmetrical dialkyl tellurium derivatives were prepared by mixing an aqueous disodium telluride solution with equimolar amounts of two different alkyl halides. All three possible dialkyl tellurium products are formed. The unsymmetrical dialkyl tellurium is the predominant species. It can be separated from the symmetrical compounds by chromatography1. This one-pot procedure takes less time to complete than the alternative route employing alkyl tellurolates (p. 387) and was used to prepare unsymmetrical dialkyl telluriums containing radioactive tellurium. Sequential addition of two alkyl halides produced only symmetrical dialkyl telluriums. 

Disodium telluride, prepared from tellurium and sodium borohydride, and 2-chloro-3-(2-chloroethyl)quinoline formed 2,3-dihydroquinolo[3,2-d]tellurophene3. 

Disodium telluride, prepared from tellurium pieces, sodium, and naphthalene in tetra-hydrofuran, reacted with allyl bromide to give diallyl telluriuml. 

Disodium telluride can be efficiently prepared from the elements in dimethylformamide at 110° and alkylated without isolation2,3. 

Dihydro-l//-2-benzotellurin, prepared from 2-(2 -bromoethyl)benzyl bromide and disodium telluride, has a much greater stability than the telluranes2. 

The ditellurium compounds, in which a Te —Te group joins two carbonyl groups, can be considered to be the tellurium analogs of peroxy compounds derived from carbonic acid or benzoic acids (e.g. benzoyl peroxides). Only a few of these compounds are known. During the reduction of aromatic nitro compounds with disodium telluride in dimethylfor-mamide, bis[dimethylaminocarbonyl] ditellurium was formed as a by-product in yields from 5 to 15%. The formation of this compound was attributed to the capture of the dimethylaminocarbonyl radical by the telluride anion and subsequent oxidation of the tellurocarbamoyl species4. 

Diorgano-4-oxo-4H-tellurins were formed in 37-67% yield from dilithium or disodium telluride and bis[organoethynyl] ketones2-5. 

Dimcthyl-4-oxo-4-phenyl-/>v-4//-l,4-teUuraphosphorm This reaction must be performed under a nitrogen atmosphere. 17.4 g (100 mmol) of disodium telluride are prepared from 4.6 g (200 mmol) of sodium and 12.8 g (100 mmol) of tellurium in liquid ammonia. When the reaction between sodium and tellurium is complete, 175 ml of methanol are cautiously added to the sodium telluride suspension in liquid ammonia. The ammonia is allowed to evaporate, and the mixture is then heated on a water bath kept at 40". Methanol is added to bring the volume to 150 ml. 6.1 g (30 mmol) of bis[l-propyn-l-yl](phenyl)phosphine oxide are added, the mixture is stirred for 5 h, 500 ml of ice/water are added, and the resultant mixture is extracted several times with chloroform. The combined extracts are filtered, and the filtrate is washed with water, dried with anhydrous magnesium chloride, and filtered. The solvent is evaporated from the filtrate under aspirator vacuum and the residue is recrystallized several times from toluene yield 7.0 g (71%) m.p. 179-182". Similarly prepared were the following compounds1 ... 

Dimcthyl-t, 4-thiatellurin 1,1-Dioxide3 A solution of 5.2 g (30 mmol) of disodium telluride in 100 ml of methanol is prepared. A solution of 3.0 g (20 mmol) of bis[propynyl] sulfone in methanol is added to the disodium telluride solution at 20°. After 10 min, the reaction mixture is poured into 300 ml of ice/water and the organic product is extracted with five portions of chloroform. The combined extracts are washed with saturated aqueous ammonium chloride solution, the organic phase is dried with anhydrous magnesium sulfate, the mixture is filtered, the filtrate is concentrated under vacuum, and the product is recryslallized from diethyl ether/pentane by cooling the solution to —25° yield 3.6 g (65%) m.p. 158°. 

Sodium 1-methylethanetellurolate and hexadecanetellurolate were obtained from sodium hydrogen telluride and the appropriate alkyl halide in THF or THF/ethanol. The sodium hydrogen telluride was prepared from tellurium and sodium borohydride in water. Equimolar amounts of disodium telluride combined with aliphatic carboxylic acid chlorides in tetrahydrofuran at — 30" and with aromatic carboxylic acid chlorides in tetrahydrofuran at 0° to give sodium tellurolates that have an acyl group bonded to the tellurium atom. These tellurolates, the sodium salts of tellurolocarboxylic acids, are dark-red substances that were obtained in almost quantitative yields. 

The reaction of disodium telluride with alkyl halides is the oldest known method for the preparation of dialkyl telluriums. The required solutions of disodium telluride can be prepared from tellurium and sodium formaldehyde sulfoxylate (Rongalite C) in aqueous sodium hydroxide (Vol. IX, p. 1048), from tellurium and sodium in liquid ammonia " dimethylformamide or tetrahydrofuran in the presence of naphthalene , from tellurium and hydrazine hydrate/sodium hydroxide in water or dimethylformamide °, from tellurium and thiourea dioxide in aqueous tetrahydrofuranor from tellurium and sodium borohydride in methanol, ethanol, tetrahydrofuran, or aqueous sodium hydroxide ... 

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