Tellurium Hydroxide Halides

Diorgano tellurium hydroxide halides with chloride bromide or iodide as the halogen are known. 

From Diorgano Tellurium Dihalides and Water or Aqueous Base 

Short chain dialkyl tellurium dichlorides are hydrolyzed to dialkyl tellurium hydroxide chlorides by the action of cold waterwhereas diaryl tellurium dihalides will react only when refluxed in water or water-containing organic solvents. Aqueous ammonia was employed to prepare dialkyl tellurium hydroxide halides  

Bis[4-hydroxyphenyl] Tellurium Chloride Hydroxide A mixture of 0.38 g (1 mmol) of bis[4-hydroxyphenyl] tellurium dichloride and 20 ml of distilled water is heated under reflux for 30 min. The solid material is filtered off, washed successively with water and water/acetone (4/1, v/v), and dried over phosphorus pentoxide yield 0.33 g (90%) m.p. 190° 

4-tetrahydro-2-benzotellurin 2-bromide 2-hydroxide diphenyl tellurium hydroxide bromide bis[3-methylphenyl] tellurium chloride hydroxide bis[2,4,6-trimethylphenyl] tellurium chloride hydroxide  

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From Diaryl Tellurium Hydroxide Halides and Potassium Iodide... 

Bisfdiorgano tellurium halide] oxides are the anhydrides of diorgano tellurium hydroxide halides. Aryl derivatives can be obtained by heating diaryl tellurium halide hydroxides to 150-180°3... 

Whether hydrolytic reactions of diorgano tellurium halides produce diorgano tellurium hydroxide halides or their anhydrides might be governed by the solubility of the anhydride, which is influenced by the halide. Treatment of the solutions obtained by boiling mixtures of diaryl tellurium dichlorides and water or treatment of aqueous solutions of diaryl tellurium hydroxide chlorides with potassium bromide1 or potassium iodide1 3 formed bis[diaryl tellurium halide] oxides. 

According to conductivity measurements, the aqueous ethanolic solutions obtained by mixing equimolar amounts of dialkyl tellurium dihalides and dihydroxides contain dialkyl tellurium hydroxide halides ... 

Alkyl and cycloalkyl halides react with benzenetellurolate to yield (cyclo)alkyl phenyl telluriums, which are converted to (cyclo)alkyl phenyl tellurium dibromides upon treatment with bromine. Stirring of a mixture of these tellurium dibromides and 0.5 M aqueous sodium hydroxide at 20° resulted in the formation of (cyclo)alkenes5. Alkyl phenyl tellurium oxides were postulated as intermediates that eliminated phenyl tellurium hydroxide. 

Dialkyl Ditellurium (Hydrazine Hydrate Method)1 6.35 g (50 mmol) tellurium is added to a stirred solution of 3.0 g sodium hydroxide (75 mmol) in 20 ml deoxygenated water. The mixture is cooled in a water bath. Hydrazine hydrate (100%, 2.5 g, 200 mmol) is added to the stirred suspension over 30 min. Stirring is continued for an additional hour at 20°. The alkyl halide (50 mmol) is then added dropwise over a period of 2-3 h. During the addition the temperature is maintained at 15 to 20". The end point of the alkylation is reached when the color of the solution changes from dark-brown to nearly colorless. The mixture is extracted with diethyl ether. The organic layer is washed with water, dried with anhydrous sodium sulfate, filtered, and the filtrate distilled to remove the solvent. The residue is distilled under reduced pressure. 

Dialkyl Ditellurium (Thiourea Dioxide Method)2 A mixture of 128 mg (1.0 mmol) of elemental tellurium, 4 mg (0.01 mmol) of cetyltrimethylammonium bromide, 0.75 ml tetrahydrofuran, and 0.5 ml dimethyl sulfoxide is heated at 80° for 15 min under an atmosphere of deoxygenated nitrogen. To this mixture is added 100 mg (1.0 mmol) of thiourea dioxide, 112 mg (2.6 mmol) sodium hydroxide, and 0.75 ml water. The resulting mixture is refluxed for 1 h. The purple solution is then cooled to 15°. Alkyl halide (2.0 mmol) is added and the mixture is stirred at 20° for 1 h. After normal work-up, the dark-red oils were passed through a pad of Celite with dichloromethane as the mobile phase. 

Diaryl ditellurium compounds disproportionate in aqueous sodium hydroxide solution to arenetellurolate and arenetellurinate. In the presence of an alkyl halide, the arenetellurolate is alkylated to aryl alkyl tellurium compound. This reaction sequence that converts half of the diaryl ditellurium molecule into desired product gives the aryl alkyl tellurium compounds in approximately 60% yield5. 

Aryl tellurium trihalides treated with water are converted to arenetellurinyl halides. The susceptibility to hydrolysis decreases from the trichlorides to the triiodides2,3. With basic aqueous solutions (sodium carbonate, sodium hydroxide) tellurinic acids or tellurinic acid anhydrides are formed2 5. 

Bis[6-(tetrahydropyran-2-yl-oxy)-l-hexyl] Tellurium2 (Thiourea Dioxide Method) Under an atmosphere of nitrogen 200 mg (2 mmol) thiourea dioxide, 112 mg (2.6 mmol) sodium hydroxide, 0.75 mt water, 0.75 ml tetrahydrofuran and 128 mg (1 mmol) tellurium are mixed. The mixture is refluxed for 1 h. Then 2 mmol of the alkyl halide and 4 mg cetyltrimethylammonium bromide are added to the pale-pink solution.The mixture is refluxed for 1 h and then worked up in the usual way. The residue is purified by column chromatography on silica gel with petroleum ether as the mobile phase. The product is isolated in 72% yield. Similarly prepared were2 ... 

Alkyl vinyl tellurium compunds were obtained when tellurium was reacted with acetylene in the presence of an alkyl halide in a system consisting of potassium hydroxide, tin(II) chloride, water, and hexamethylphosphoric triamide2,3. Divinyl tellurium (53-60% yield) and dialkyl telluriums (4-12% yield) were also formed in these reactions. 

Alkoxycarbonylalkyl organo telluriums are conveniently prepared from tellurolates and alkoxycarbonylalkyl halides. The esters can be saponified in refluxing aqueous ethanol containing potassium hydroxide or sodium hydroxide. 

The tendency to replace halide by hydroxide decreases in diorgano tellurium dihalides from chlorine to iodine. In cold or boiling water the dichlorides are converted to diorgano... 

Some diaryl tellurium dihalides did not give diaryl tellurium halide hydroxides upon treatment with boiling water, but instead deposited the anhydrides3. 

Diphenyl Tellurium Dinitrate1 In a beaker are placed 5 g (18 mmol) of diphenyl tellurium, 20 ml of halide-free nitric acid (d = 1.2) are added, and the initially exothermic reaction is allowed to subside. The mixture is then heated on a boiling water bath for 10 min, the remaining nitric acid is allowed to evaporate in a vacuum dessicator over potassium hydroxide, and the solid residue is recrystallized from chloroform m.p. 160°. 

Solutions of sodium tellurite in water or prepared from tellurium dioxide and aqueous sodium hydroxide were acidified with sulfuric acid and treated with freshly prepared solutions of bis[2-hydroxyethyl]dithiocarbamic acid in aqueous methanol. Addition of aqueous solutions of potassium chloride, iodide, or thiocyanate led to the deposition of crystalline tris[bis(2-hydroxyethyl)dithiocarbamate] halides. 

Treatment of aryl tellurium halides with base (ethanolic potassium hydroxide , aqueous sodium hydroxide, triethylamine , tris[(-propyl] phosphite , triphenylphosphane ) leads to the formation of diaryl ditellurium compounds (p. 273). In the hydrolytically induced disproportionation reactions, aryl tellurinic acids are the other tellurium-containing products ... 

Disodium ditelluride can be prepared from tellurium and sodium in liquid ammonia, lithium triethylborohydride in THF, sodium borohydride in ethanol or THF" lithium or sodium in ethylenediamine , sodium hydride in DMF , hydrazine hydrate in aqueous sodium hydroxide , thiourea dioxide in DMF/THF/aqueous sodium hydroxide, and sodium formaldehyde sulfoxylate (Rongalite C) " in aqueous sodium hydroxide. The reducing agents compatible with organic solvents provide reaction media in which long-chain aliphatic halides are soluble. Such halides are insoluble in liquid ammonia, or aqueous media. 

The reduction of aryl tellurium halides to the corresponding diaryl ditelluriums is of synthetic utility only for compounds with stabilizing substituents in the orf/io-position to tellurium (p. 242). Diaryl ditellurium products are obtained in excellent yields from such aryl tellurium halides upon reduction with sodium disulfite, zinc, hydrazine hydrate, or sodium borohydride , or upon treatment with aqueous potassium hydroxide. ... 

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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