From sodium telluride and non-activated aryl halides

1 From sodium telluride and non-activated aryl halides 

The normal low reactivity of aryl halides towards nucleophilic reagents is not generally observed in their reaction with alkali tellurides. The observed reactivity seems to be 

Non-activated aryl halides react only moderately with sodinm tellnride prepared from the elements in inert solvents (DMF, iV-methyl-2-pyrrolidone (NMP), hexamethylphos-phoric acid triamide (HMPA)).  

Better results are achieved with tellurium and sodinm hydride in DMF.  

Diaryl tellurides (generalprocedure). A mixture of powdered Te (0.128 g, 1.0 mmol), NaH (0.053 g, 2.2 mmol, 60% suspension in oil, washed with hexane) and dry DMF (3 mL) is heated at 140°C for 1 h. Within 0.5 h the initial deep red colour is lost, and a pale yellow snspension is obtained. After cooling at room temperature, the aryl iodide (2.0 mmol) in dry DMF (3 mL) is added and the mixture heated at 130°C for 24 h. After cooling at room temperatnre, the mixture is quenched with 10% aqueous NH4HSO4 (10 mL) and extracted with ether (10 mL). The ethereal extract is washed with HjO, dried (Na2S04) and evaporated, giving the teUuride, which is purified by column chromatography on SiOj (elnent/hexane). 

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