The halogen-metal interconversion reaction now makes possible the preparation of hitherto difficultly or completely inaccessible organolithium compounds from the corresponding bromo- or iodo-nuclear substituted nitrogen heterocycles by means of other organolithium compounds like n-propyllithium and n-butyllithium : C5H4NBr +n-C4H9Li ( 3-bromopyridine) → C5H4NLi +n-C4H9Br ( 3-pyridyllithium). These organolithium compounds of the nitrogen heterocycles are of a relatively high order of reactivity with other functional groups. Some of the types reported on in the pyridine series are: 1. 3-pyridyllithium in 70 per cent yield from 3-bromopyridine and n-butyllithium, 2. 3-quinolyllithium in 52 per cent yield from 3-bromopyridine, 3. 5-bromo-3-pyridyllithium in 41 per cent yield from 3, 5-dibromopyridine and slightly more than two equivalents of n-butyllithium. In the carbazole series, some of the organolithium compounds rep0rted are: 1. N-ethyl-2, 8-dilithiocarbazole in 84-91 per cent yield from N-ethyl-2, 8-dibromocarbazole, and in 79-92 per cent yield from the corresponding di-iodo-compound. 2. N-ethyl-2-lithiocarbazole 1 from the corresponding iodocarbazole in 68 per cent yield.
Proceedings of the Iowa Academy of Science
©1940 Iowa Academy of Science, Inc.
Spatz, Sydney M. and Gilman, H.
"New Synthetic Tools in the Pyridine, Quinoline and Other Nitrogen-Heterocyclic Series,"
Proceedings of the Iowa Academy of Science, 47(1), 262-263.
Available at: https://scholarworks.uni.edu/pias/vol47/iss1/51