Ring transformations in reactions of heterocyclic halogeno compounds with nucleophiles (iii) conversion of 2,6‐dibromopyridine by potassium amide in liquid ammonia into 4‐amino‐2‐methylpyrimidine

Abstract

Abstract Reactions of 6‐substituted derivatives of 2‐halogenopyridines with potassium amide in liquid ammonia have been investigated. Together with aminations leading to the formation of 2‐amino compounds, two unusual reactions were found to occur, i.e. reactions partially involving meta ‐rearrangement and conversions involving a ring transformation. The rearrangements took place in aminations of various substances ( e.g. of 2‐bromo‐6‐methylpyridine, 2‐chloro‐6‐methylpyridine and 2‐bromo‐6‐ethoxypyridine). Ring transformations occurred in aminations of 2,6‐dibromo‐ and 2,6‐dichloro‐pyridine, 4‐amino‐2‐methylpyrimidine being formed. The mechanism of the remarkable reaction last‐mentioned is discussed.