Reactions of polyfluoropyridines with bidentate nucleophiles: attempts to prepare deazapurine analogues

Reactions of pentafluoropyridine with guanidine, thiourea and urea with the hope of preparing derivatives which may be cyclised to polyfluorodeazapurines are described The reactions with urea and thiourea produced, somewhat unexpectedly, bis-(2,3,5,6-tetrafluoro-4-pyridyl)amine and bis-(2,3,5,6-tetrafluoro-4-pyridyl)sulfide, respectively, the structure of the amine was confirmed by X-ray crystallography. The product from the guanidine reaction was the expected 4-substituted tetrafluoropyridine derivative. Attempts to cyclise the latter are described and a rationalisation to explain the unexpected melamine derivatives which were produced is given.