With Anion Exchange Resins in the Carboxylate Form

Diaryl tellurium dicarboxylates were prepared in good yields from diaryl tellurium dichlorides and anion exchange resins such as Amberlite IR45 and Amberlite IR400 in their carboxylate form. The carboxylate resins were obtained by treating the resins in the OH -form with carboxylic acids or the resins in the Cl -form with sodium carboxylates .  

Diaryl TeUurium Dicarboxylates 5g of Amberlite IR45 resin in the OH -form (theoretical exchange capacity 2 mequiv/ml) are placed in a 10 mm ID glass tube. A 4% ethanolic solution of the carboxylic acid in ethanol is slowly passed through the resin until the conversion to the carboxylate form is complete. The resin is washed with ethanol to remove excess carboxylic acid and dried in a stream of nitrogen. 1 mmol of the diaryl tellurium dichloride is dissolved in 20 ml of THF/ethanol (1 /I, v/v) and this solution is slowly passed through the resin. The resin is rinsed with 50 ml of the solvent mixture, the combined effluents are evaporated in a rotary evaporator, and the crude dicarboxylates, obtained in 100% yield, are recrystallized from benzene/petroleum ether. 

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