Tellurium Acetate

Phenylazo)phenyl tellurium acetate was prepared from the aryl tellurium chloride and sodium acetate. The tellurium atom is in a trigonal bipyramidal environment with the oxygen and one nitrogen atom in the two axial positions1. 

In contrast to the alkyl aryl tellurium acetal derivates in which the acetal-carbon is bonded to an aryl group, 2-dialkoxyethyl phenyl tellurium compounds, derivatives of an aliphatic aldehyde, are decomposed when treated with acid and do not form the expected aldehyde1,2. 

Bis[diphenyl tellurium acetate oxide was obtained in 64% yield when equimolar amounts of diphenyl tellurium oxide and diphenyl tellurium diacetate were refluxed in benzene2. The corresponding trifluoroacetate was prepared with methanol as the reaction medium3 at 20°. 

Bis[diphenyl tellurium acetate] Oxide2 A hot solution of 13.44 g (33 mmol) of diphenyl tellurium diacetate in 30 ml benzene is added to a boiling suspension of 10 g (33 mmol) of diphenyl tellurium oxide in 50 ml benzene. Approximately 50 ml benzene are distilled from the reaction mixture and 30 ml hot hexane are added to the residual solution. The mixture is slowly cooled. Colorless crystals form yield 64% m.p. 143-146° (from acetone/hexanc). 

When these reactions are carried out in acetic acid as the reaction medium, the 2-acyloxyalkyl phenyl tellurium acetates are isolated (see page 610). 

When phenylacetylenes (3 mol), tellurium dioxide (1 mol), and a lithium halide (14-18 mol) were refluxed in acetic acid, 3-halobenzotellurophenes were obtained in yields ranging from 21 to 92%2. A tellurium(IV) acetate halide, formed from tellurium dioxide, lithium halide, and acetic acid, probably adds to the carbon-carbon triple bond of the phenylacetylene. The intermediary 2-phenyl-2-haloethenyl tellurium acetate halide cyclizes probably by loss of acetic acid. The 3-halobenzotellurophene Te, 7e-acetate halide is then reduced to 3-halobenzotellurophene by an excess of the phenylacetylene. Diphenylacety-lene and diphenyldiacetylene did not react under these conditions. 

Phenylazo)phenyI Tellurium Acetate A solution of 0.082 g (1 mmol) of sodium acetate in 20 w/ dry methanol is added under an atmosphere of nitrogen to a stirred solution of 2-(phenylazo)phenyl tellurium chloride (0.344 g, 1 mmol) in 25 mldichloromcthane at 20°. The mixture is stirred for 20 min and the solvents removed on a rotary evaporator. 100 ml dichloromethane are added to the residue. The mixture is stirred vigorously and then filtered to remove insoluble sodium chloride The solvent is removed from the filtrate on a rotary evaporator. 5 ml methanol are added to the residue, the mixture is stirred well, and then filtered to collect the product. The crude material is dissolved in petroleum ether (60-80°). Slow evaporation of the solvent caused golden-orange crystals to form yield 75% [Pg.238]

Phenylazo)phenyl tellurium chloride and sodium acetate produced the expected aryl tellurium acetate" (p. 238). 

Type 5 tellurenyl bromides are not easily accessible. They were prepared by refluxing an acetic acid solution of tellurium dibromides 6 in the presence of catalytic amounts of HBr [96ZOK1434 97JOM(536-537)233]. The reaction is not easily reproducible, affording the tellurenyl bromides in rather low yields. 

Blatter erde, /. potassium acetate. Oba. erz, n. foliated tellurium (oagyagite). blatterformig, a. in the form of leaflets or flakes laminated leaf-shaped. 

Tellurium Nitride. Te3N4, mw 438.87, N 9.58%, yellow amorph powd, mp (explds above 200° or when quickly heated). Decompd by w (under vac the heat of soln causes deton). Insol in aq ammonia dil acet ac. Prepd by reacting gaseous ammonia with TeCl4 at —15° Te3N4 is unaffected by heating to 150°. 

Sodium hydrogen telluride is prepared by reduction of tellurium with NaBH4 under several conditions. The original procedure uses ethanol as the solvent, adding, after complete reduction of the tellurium, an appropriate amount of acetic acid (see Section 4.1.2, ref. 10 Section 4.1.7, ref. 29). 

Method B. Typical procedure. A mixture of elemental tellurium (0.127 g, 1 mmol) and sodium hydride (0.0528 g 2.2 mmol) in dimethylformamide (3 mL) was heated at 140°C under nitrogen and magnetic stirring for 1 h. The resulting violet solution was cooled to 0°C in an ice bath and treated dropwise with a solution of ethyl a-(phenylseleno) mesityl acetate (0.361 g, 1 mmol) in DML (2 mL). A vigorous reaction occurred and the colour of the solution changed from violet to dark brown. After the addition the mixture was diluted... 

Bis(p-methoxyphenyl) tellurium diacetate or ditosylate is generated by the electrolysis of the parent telluride in the presence of BU4N+ acetate or tosylate. Like the telluroxide, they accomplish the conversion of thioamides into nitriles and 1,2,4-thiadiazoles. Taking into consideration of these facts, the above conversion can be performed in an electrochemical... 

Diacetoxylation of olefins with benzenetellurinic anhydride (typical procedure) To a solution of (PhTe0)20 (0.95 g, 2.1 mmol) in dry HOAc (15 mL) is added styrene (0.208 g, 2.0 mmol) in HOAc (4 mL) and 98% H2SO4 (0.020 g, 0.2 mmol) in HOAc (1 mL). The mixture is gently refluxed for 24 h, which turns red with deposition of a small amount of elemental tellurium. After removal of tellurium (0.071 g, 0.56 mmol) by fdtration, the solvent is evaporated, the residue extracted with ether and the ether extract dried (MgS04). Chromatography on Si02 gives the v/c-diacetate (0.363 g (82%)) and 1-phenylethyl acetate (0.029 g (9%)). 

Typical procedure A solution of 4-pentenoic acid (0.0500 g, 0.500 mmol), bis(p-chlorophenyl)tellurium diiodide (0.302 g, 0.500 mmol) and pyridine (0.040 g, 0.500 mmol) was heated at reflux in 20 mL of chloroform for 5 days. The reaction mixture was concentrated in vacuo, and the residue was purified via chromatography on silica gel eluted with 1 1 hexane/ethyl acetate to give 0.073 g (66%) of the iodolactone and 0.140 mg (80%) of diaryl telluride. 

Tellurium dioxide in acetic acid/lithium chloride reacts with 2 equiv of / or 5-hydroxy-olefins, giving tetrahydrofuran or tetrahydropyran dichlorotelluro derivatives. ... 

Bromobenzotellurophene ° A mixture of 2.0 g (19.6 mmol) of phenylacetylene, 1.0 g (6.3 mmol) of tellurium dioxide, 2.0 g (23 mmol) of lithium bromide aud 50 uiL of acetic acid is heated uuder reflux for 20 h, cooled to 20°C, aud poured iuto 150 uiL of diethyl ether. Aqueous sodium hydrogeu carbouate solutiou (5%) is added uutil all the acid has beeu ueutralized. The orgauic phase is separated, dried with auhydrous calcium chloride, fdtered aud evaporated. The browu, oily residue is dissolved iu a mixture of 30 mL of carbou tetrachloride aud 10 mL of petroleum ether (b.p. 30 0°C). Chloriue is carefully bubbled through this solutiou uutil precipitatiou of the product ceases. The yellow precipitate is filtered and recrystallized from acetonitrile. Yield 2.2 g (92%) m.p. 263-265°C. 

Carboxybenzotellurophene A mixture of 15.5 g (53 mmol) of 2-formylphenyl car-boxymethyl tellurium, 50 niL of pyridine and 50 niL of acetic anhydride is heated under reflux for 2 h. Most of the solvent is then evaporated under vacuum, and the residue is extracted with boiling of 1 M aqueous sodium hydroxide solution. The extract is neutralized, the precipitate is filtered off and the solid is recrystallized from ethanol/benzene. Yield 11.6 g (80%) m.p. 206-208°C. 

Cadmium acetate is used for glazing ceramics and pottery in electroplating haths in dyeing and printing textiles and as an analytical reagent for sulfur, selenium, and tellurium. 

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