Tellurium Carboxylate Halides

Equimolar amounts of diaryl tellurium dichlorides and sodium or silver trihaloacetates were stirred and refluxed for 3 h in benzene. The silver chloride was removed by filtration and the filtrate evaporated under reduced pressure. The residue was recrystallized from chloroform/petroleum ether (5 1) to give diorgano tellurium chloride trihaloacetates b 

When diaryl tellurium dichlorides and equimolar amounts of ketoximes were stirred for 3 h at 20° in benzene in the presence of triethylamine as hydrogen-chloride scavenger, diaryl tellurium ketoximate chlorides were obtained as white sohds.  

Bis[diorgano 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° T 

Irgolic Organo Tellurium Compounds with 2 Te—C Bonds or 1 Te=C Bond 

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

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Diorgano Tellurium Carboxylate Halides/Oximate Chlorides... 

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

This sequence of reactions transfers the alkyl group of a carboxylic acid to the tellurium atoms of a diaryl ditellurium. Because many carboxylic acids are commercially available at prices much lower than the corresponding alkyl halides, this reaction is a very useful alternative route to unsymmetrical diorgano tellurium compounds. 

To Diorgano Tellurium Dihalides/Pseudo halides/ Carboxylates... 

Ethynyl phenyl telluriums, obtained from ethynyl lithiums and phenyl tellurium halide, are carboxylated in methanol in the presence of triethylamine and palladium(II) chloride to methyl ethynylcarboxylates5. 1,4-Diorgano-1,3-butadiynes are by-products in these reactions. 

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. 

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