From Organo Tellurium Halides and Metal Cyanides

From Organo Tellurium Halides and Metal Cyanides 

Exchange of halide for cyanide in organo tellurium halides occurs easily when the tellurium halide is fused with anhydrous silver cyanide or treated with potassium cyanide in methanoP, DMSO or ethanol/dimethyl sulfoxide . 

2-Benzoylphenyl Tellurium Cyanide An intimate mixture of 1.65 g (5 mmol) of 2-benzoylphenyl tellurium chloride and 1.5 g (10 mmol) of anhydrous silver cyanide is heated in an oil bath until the material has melted. The mixture is then allowed to cool to 20° and is extracted with chloroform. The chloroform extract is evaporated to dryness and the residue is recrystallized from hexane/benzene yield 1.3 g (80%) m.p. 135°. Similarly prepared was  

2-Ethoxycarbonylbenzyl Tellurium Cyanide A dark colored solution of 0.52 g (1.28 mmol) of 2-bromocarbonylbenzyl tellurium bromide in 10 ml of ethanol is added dropwise to a suspension of 0.30 g (4.6 mmol) of potassium cyanide in 5 ml of DMSO. The resultant yellow solution is stirred for 30 min and then poured into a mixture of 50 ml water/50 ml diethyl ether. The organic phase is separated, extracted several times with water, and dried with anhydrous calcium chloride. The diethyl ether is evaporated and the oily residue crystallizes on standing yield 0.28 g (69%) m.p. 72-73 (carbon tetrachloride/hexane). Similarly prepared was  

The aryl tellurium halides do not have to be isolated but can be generated by reduction of aryl tellurium trihalides and reacted in situ with potassium cyanide s. 

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