From Other Dibenzoyl Tellurium Compounds

Bis[2-nitrobenzoyl] and bis[4-nitrobenzoyl] tellurium dichlorides were reduced to the corresponding amino derivatives by Raney Nickel/hydrogen or hydrazine. The bis[ami-nobenzoyl] tellurium dichlorides were converted to the hydroxy derivatives via the diazonium salts. The same hydroxy derivatives were obtained through demethylation of the methoxy compounds with aluminum trichloride .  

Bis[2-aminobenzoyl] Tellurium Dichloride 0.5 g (1 mmol) of bis[2-nitrobenzoyl] tellurium dichloride are dissolved in too w/of absolute ethanol, 100 mg of Raney nickel are added, and 5 m/of hydrazine are added to the stirred ethanol solution kept at 20°. The mixture is stirred for 6h, filtered, and the filtrate is concentrated. The residue is recrystallized form absolute ethanol yield 0.27 g (55%) m.p. 330°. Similarly prepared was bis[4-aminobenzoyl tellurium dichloride yield 70% m.p. 120°. 

Hydrazine, that generally reduces diorgano tellurium dihalides in refluxing ethanol to diorgano telluriums (p. 430), does not react with the TeClj group of dibenzoyl tellurium dichlorides at 20°. 

Bis[2-hydroxybenzoyl] Tellurium Dichloride (Diazonium Method) 0.44 g (1 mmol) of bis[2-aminobenzoyl] tellurium dichloride are suspended in 2.5 ml of 5 molar hydrochloric acid and the suspension is cooled to 0°. 0.4 g of sodium nitrite dissolved in 5 ml of water are gradually added to the stirred suspension of the tellurium compound. The diazonium solution is then added dropwise to 50 ml of 2 molar sulfuric acid at 60° and the mixture is stirred for 6 h. The resultant mixture is repeatedly extracted with chloroform, the combined extracts are dried with anhydrous sodium sulfate, filtered, and concentrated. The residue is rccrystallized from petroleum ether (b.p. 60-80°) yield 0.18 g (48%) m.p. 290°. 

Similarly prepared was bis 4-hydroxybenzoyl tellurium dichloride yield 55% m.p. 163°. 

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