Electrophilic substitution of heteroaromatic compounds. Part 54. Intramolecular base-catalysed hydrogen exchange at the 3-position in substituted pyridines
Abstract
Various O-linked substituents at the 4-position of a pyridine ring enhance the rate of base-catalysed hydrogen exchange at the 3,5-ring positions. An intramolecular proton-abstraction mechanism is proposed.