Facile Preparation of 6-Bromopyridine-2-carboxamide and Pyridine-2,6-dicarboxamide: Partial Aminocarbonylation of 2,6-Dibromopyridine

Abstract

The palladium-catalyzed carbonylation of 2,6-dibromopyridine in the presence of primary amines under controlled conditions (carbon monoxide pressure) gives mainly N-aryl- or N-alkyl-6-bromopyridine-2-carboxamides accompanied by N,N′-diaryl- or N,N′-dialkylpyridine- 2,6-dicarboxamides. Further aminocarbonylation of the N-aryl- and N- alkyl-6-bromopyridine-2-carboxamides affords unsymmetric N,N′- diaryl, N-alkyl-N′-aryl-, or N,N′-dialkylpyridine-2,6-dicarboxamides.