Hetarynes IX: Reactions of some bromoethoxypyridines with lithium piperidide in piperidine

Reactions of 3-bromo-4-ethoxypyridine and 2-bromo-6-ethoxypyridine with lithium piperidide in piperidine have been investigated. It was found that in these compounds both substituents when occupying positions 2,4 or 6 are replaced by the piperidino group without rearrangements occurring. From 3-bromo-4-ethoxypyridine some 2,4-dipiperidinopyridine is formed as an additional product, probably via 4-piperidino-2,3-pyridyne as an intermediate.