With Hydrazine or Sodium Sulfide

The ethynyl group is cleaved in phenylethynyl alkyl telluriums by hydrazine in basic ethanolic medium. The sodium alkanetellurates were oxidized to the corresponding dialkyl ditelluriums. 

Sodium sulfide will split the benzoylmethyl group from 4-methoxyphenyl phenacyl tellurium dichloride as evidenced by the formation of bis[4-methoxyphenyl] ditellurium. The aryl phenacyl tellurium is the intermediate in this reaction. 

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Dimethyl-lO-ethylphenotellurazine reacted with sulfuryl halides or bromine in diethyl ether solution to quantitatively precipitate re,7e-dihalides. The dihalides were recrystallized from chlorobenzene. The dihalides can be reduced to the parent heterocycle with hydrazine or sodium sulfide. ... 

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