EVIDENCE IN FAVOR OF LITHIUM HALOGEN EXCHANGE BEING FASTER THAN LITHIUM ACIDIC HYDROGEN (DEUTERIUM) EXCHANGE

Treatment of 2-iodo-3-(deuterioxymethyl)quinoline with 1.5 equiv of n-butyllithium in ether, followed by aqueous work up, furnished 2-deuterio-3-(hydroxymethyl)quinoline in greater than 50% yield, confirming our earlier report,2 which has been questioned by Beak and co-workers in this journal.1 A mechanism is proposed, in which the reaction of n-butyllithium is faster with C-I bond than with acidic deuterium. Further experiments are described in which the reaction of n-butyllithium is also faster with the C-I bond than with the ester carbonyl group. © 1990, American Chemical Society. All rights reserved.