POLYFLUOROHETEROCYCLIC COMPOUNDS .16. TETRAFLUOROPYRIDINE-3- AND -4-CARBALDEHYDES AND SOME DERIVATIVES OF LATTER

Tetrafluoro-3- and -4-lithiopyridines behave normally in reacting with N-methylformanilide to give tetrafluoropyridine-3- and -4-carbaldehydes. The 4-carbaldehyde can be oxidised and reduced to the corresponding acid and carbinol respectively. It also reacts with pentafluorophenyl-lithium and tetrafluoro-4-lithiopyridine to give the corresponding secondary alcohols, which can be oxidised to pentafluorophenyl tetrafluoro-4-pyridyl and bis(tetrafluoro-4-pyridyl) ketones. The latter will react with more tetrafluoro-4-lithiopyridine to give tris(tetrafluoro-4-pyridyl)methanol, which can also be prepared from ethyl tetrafluoroisonicotinate and tetrafluoro-4-lithiopyridine.