With Cleavage of the Tellurophene Ring

Butyl lithium in hexane cleaved 3-bromobenzotellurophene, even at — 50°, forming butyl 2-ethynylphenyl tellurium.  

Butyl 2-Ethynylphcnyl Tellurium A solution of 0.5 g (1.6 mmol) of 3-bromobenzotellurophene in 30 ml of diethyl ether is cooled to — 50°, 1.95 mmol of butyl lithium in hexane are added, and, after 30 min, the mixture is hydrolyzed with wet diethyl ether and then with water. The organic phase is separated, dried with anhydrous calcium chloride, filtered, and evaporated. The oily residue is chromatographed on silica gel with petroleum ether as the mobile phase to give an oil (Rf = 0.5) yield 0.33 g (71%). 

3-Oxo-2,3-dihydrobenzotellurophenes were cleaved by sodium hydrogen sulfite, hypo-phosphorous acid5 and concentrated hydrobromic acid . 

Benzo[l,2-c 3,4-c 5,6-c ]tritellurophene might have been prepared by dehydrogenation of the product obtained in the reaction between hexakis[bromomethyl]benzene and lithium telluride. Experimental details for the preparation of these compounds were not reported. 

Naphtho[l,2-6]tellurophene was obtained by dehydrogenation of 4,5-dihydronaphtho-[1,2-/)]tellurophene (see tellurophene, p. 733) with dichlorodicyanobenzoquinone .  

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