From Disodium Ditelluride

Diaryl Ditellurium Compounds Preparation 1. From Disodium Ditelluride... 

The halogenolysis of dialkyl ditellurium compounds is a convenient method for the preparation of alkyl tellurium trihalides because dialkyl ditellurium compounds are easily accessible through alkylation of disodium ditelluride (p. 258). Diaryl ditellurium compounds generally obtained via reduction of organo tellurium trichlorides (p. 274), serve as starting materials for the syntheses of aryl tellurium tribromides and triiodides (Vol. IX, p. 1156) that are not obtainable from the hydrocarbons and tellurium telrabromide or tetraiodide. 

Disodium ditelluride can be prepared from tellurium and sodium in liquid ammonia, lithium triethylborohydride in THF, sodium borohydride in ethanol or THF" lithium or sodium in ethylenediamine , sodium hydride in DMF , hydrazine hydrate in aqueous sodium hydroxide , thiourea dioxide in DMF/THF/aqueous sodium hydroxide, and sodium formaldehyde sulfoxylate (Rongalite C) " in aqueous sodium hydroxide. The reducing agents compatible with organic solvents provide reaction media in which long-chain aliphatic halides are soluble. Such halides are insoluble in liquid ammonia, or aqueous media. 

Ditellurane (26) is formed in 11-15% yield from 1,4-diiodobutane and freshly prepared disodium ditelluride in a water-benzene system containing a phase transfer agent (Equation (2)). Unfortunately, the yield is low and the product is accompanied by a polymer [Te2(CH2)4] <88JOM(338)9>. 

Biphenylene was observed among the products of the reaction of o-chloronitrobenzene with disodium ditelluride, and is thought to arise from benzyne dimerization. The major product, however was phenazine (102). 

Benzo-1,3-ditellurole 54 was prepared in 40-47% yield by reacting dibro-momethane with disodium benzene-o-ditellurolate in ethanol, the latter generated in situ through reduction of poly(o-phenylene)ditelluride 55 with NaBH4 (88KGS1144 91 MI 1). The polymeric ditelluride 55, in turn, was obtained from a two-step procedure starting with bis-(o-trimethylsilyl)-benzene. 

---