Tetrahedron

Directed lithiation of unprotected pyridinecarboxylic acids: syntheses of halo derivatives

J Lazaar, AS Rebstock, F Mongin, A Godard, F Trécourt…

Index: Lazaar, Jalal; Rebstock, Anne-Sophie; Mongin, Florence; Godard, Alain; Trecourt, Francois; Marsais, Francis; Queguiner, Guy Tetrahedron, 2002 , vol. 58, # 33 p. 6723 - 6728

Full Text: HTML

Citation Number: 29

Abstract

Deprotonation of all isomeric lithium pyridinecarboxylates and subsequent trapping with hexachloroethane or iodine afforded straightforward access to chloro-and iodopyridinecarboxylic acids, respectively. Starting from lithium 5-bromonicotinate, the introduction of an iodine atom at C4 and further halogen migration allowed the potential of this method to be extended to the synthesis of more elaborate derivatives.