Reactions of bromo‐derivatives of 2‐ and 3‐ethoxypyridine when heated with hydrochloric acid solution

Abstract

Abstract The behaviour of bromo‐derivatives of 2‐ and 3‐ethoxypyridine, when heated with aqueous hydrochloric acid, has been investigated. From 6‐bromo‐2‐ethoxypyridine , 6‐chloro‐2‐hydroxypyridine and from 2‐bromo‐3‐ethoxypyridine , 2‐chloro‐3‐hydroxypyridine are formed together with the corresponding dihydroxypyridines. During the heating of 5‐bromo‐3‐ethoxypyridine the bromine atom is not replaced, but the ethoxy group is substituted by the hydroxyl group. Both 3‐bromo‐2‐ethoxypyridine and 5‐bromo‐2‐ethoxypyridine are converted into a mixture of 3,5‐dibromo‐2‐hydroxypyridine and 2‐hydroxypyridine. We also observed a migration of the bromine atom in the corresponding benzene derivative ( 4‐bromophenetole ), contrary to what is recorded in the literature. Halogeno‐derivatives of 6‐bromo‐2‐ethoxypyridine and 5‐bromo‐3‐ethoxypyridine react in the way expected from the data given above.