Pyridine‐4‐thiol and Amphoteric Analogs: Novel Protection of Aryl Bromides in Strong Alkali

Abstract

The use of pyridine-4-thiol (PT) to preserve certain aryl bromides in strong alkali is reported (Scheme 1). The presence of this additive or of some of its amphoteric analogs such as 3-hydroxypyridin-4(1H)-ones suppresses the replacement of the Br-substituent by hydroxide and alkoxide ions. A mechanistic interpretation of the effect is proposed.