From sodium telluride and two different alkyl halides

1 From sodium telluride and two different alkyl halides 

Unsymmetrical telluro-substituted fatty esters (of biological interest) are obtained in about 40% yield after chromatographic separation from the symmetrical tellurides.  

Aryl alkyl tellurides are prepared in medium yields by sequential arylation/alkylation of Na2Te generated by the described Te/NaH/NMP system (see Section 3.1.2.1).  

Methyl 2-naphthyl telluride (typicalprocedure 2-lodonaphthalene (0.150 g, 0.59 mmol) is added dropwise to a stirred solntion of NajTe (1.3 mmol) in NMP (4 mL) and the mixture is heated at 120°C for 5 h. An excess of Mel (0.40 mL, 4.3 mmol) is then added and the resulting mixtnre is stirred at 50°C for 2 h. Usual work-up gives the telluride as pale yellow crystals (0.110 g (67%) m.p. 59-60°C). 

The magnesium aryl tellurolates described earlier have seldom been employed for the preparation of unsymmetrical tellurides.  

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