D. Cai, D. Hughes, T. Verhoeven
Apr 8, 1996
Citations
1
Influential Citations
49
Citations
Journal
Tetrahedron Letters
Abstract
Mono-lithiation of 2,6-dibromopyridine by n-BuLi is complicated by deprotonation of the pyridine ring by the resulting mono-lithium species. This problem can be eliminated by a reverse addition, but this causes formation of the undesired dilithio species. However, rapid lithium-halogen exchange between 2,6-dibromopyridine and 2,6-dilithiopyridine produces 2-bromo-6-lithiopyridine cleanly. Thus, using reverse addition, the mono-lithiated pyridine can be generated in 98% yield.