With Replacement of a Methylene Hydrogen Atom in Telluraxanthene

With Replacement of a Methylene Hydrogen Atom in Telluraxanthene 

Telluraxanthene was converted to 9-lithiotelluraxanthene in a reaction with phenyl lithium. The lithiotelluraxanthene and carbon dioxide reacted to produced 9-carboxytellura-xanthene.  

9-Carboxytelluraxanthene A solution of phenyl lithium is prepared from 3.5 g (22 mmol) of bromobenzene and 0.3 g (44 mmol) of lithium in 50 ml of absolute diethyl ether. This solution is added to a stirred solution of 5.88 g (20 mmol) of telluraxanthene in 50 ml of absolute benzene, the mixture is stirred at 20° for 1 h, and then heated under reflux for 1 h. The resultant dark red solution of 9-lithioteUuraxanthene is poured onto dry ice, the carbon dioxide is allowed to evaporate, and the solution is shaken with aqueous sodium hydroxide solution. The aqueous layer is separated, extracted several times with benzene, and acidified with concentrated hydrochloric acid. The precipitate is filtered, washed with ice/water, and dried yield 4.4 g (65%) m.p. 209° (dec., from ethanol). 

Sadekov, A. A. Ladatko, V.l. Minkin, Khim. Geterotsikl. Soedin. 1978, 1567 engl. 1280. I.D. Sadekov, A.A. Ladatko, V.l. Minkin, Khim. Geterotsikl. Soedin 1980, 1342 engl. 1016. 

Lithium aluminum hydride reduced 9-hydroxy-9-(4-methylphenyl)-telluraxanthene to 9-(4-methy lphenyl)-telluraxanthene.  

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