2.6- diphenyl-4- ethylidene -47/-tellurin

Diphenylseleninium-4-yl)ethylidene]-2,6-diphenyl-4-oxo-4i/-tellurin4 0.50 g (1,4 mmol) 2,6-diphenyl-4-oxo-4/7-tellurin and 0,5 g (1.1 mmol) of 2,6-diphenyl-4-ethylseleninium hexafluorophosphate are heated in 2 ml acetic anhydride for 10 min on a steam bath. The mixture is diluted with 5 ml of acetonitrile and 40 m of diethyl ether. The product precipitates i n the form of green crystals on cooling. The crystals are isolated by filtration yield 33% m.p. 151-156°. 

When 2,6-diphenyl-4-methyl-l-tellurinium tetrafluoroborate and dimethylthioformamide were heated in acetic anhydride, 2,6-diphenyl-4-[2-(N,N-dimethyliminio)-ethylidene]-4H-tellurin tetrafluoroborate was isolated3. 

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