From Tellurium Dioxide or Sodium Tellurite

A mixture of tellurium dioxide and at least four molar equivalents of an alkanethiol reacted without solvent or in the presence of diethyl ether to yield bi alkylthio] tellurium derivatives.  

Bisfi-propylthio) tenurium A mixture of 1.9 / /(0.02 mol) of isopropanethiol, 0.8 g (0.005 mol) of tellurium dioxide, and 5 ml of diethyl ether is stirred for 2 h. The mixture is filtered. The filter cake is washed with 20 ml of methanol. The combined washings and filtrate are cooled to — 15°. The yellow crystals are collected by filtration, washed with methanol, and dried in air yield 0.48 g (35%) m.p. 33°. 

Irgolic Organo-tellurium Compounds without a C,Te-Bond 

Sodium tellurite, prepared by dissolution of tellurium dioxide in aqueous sodium hydroxide, reacted with carboxymethanethiol and with 1-carboxy-l-ethanethioP to form bis[carboxyalkylthio] tellurium compounds. The reactions must be carried out in acidic solutions, because base decomposes the bis[alkylthio] tellurium derivatives. With an excess of thiol, compounds with more than two alkylthio groups bonded to the tellurium atom were observed .  

Bis[1-carboxy-I-ethylthio] Tellurium 0.75 g (5 mmol) of tellurium dioxide are dissolved in 5 ml of 2 molar aqueous sodium hydroxide solution and this solution is added dropwise to a stirred solution of 2.5 g (24 mmol) of 1-carboxy-l-ethanethiol in 10 ml of water. The resultant yellow aqueous mixture is extracted several times with diethyl ether, the extracts arc combined, diethyl ether is removed at 20°, and the oily residue is kept under nitrogen for 7 days to allow crystals to form. The crystals are collected, dissolved in diethyl ether, and reprecipitated with petroleum ether yield 1.3 g (76%) m.p. 114°. 

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