Rearrangement of 4-amino-3-halo-pyridines by nucleophilic aromatic substitution.

The reaction of 3-halo-4-aminopyridines with acyl chlorides and triethylamine is described. The pyridin-4-y1 alpha-substituted acetamide products were obtained in moderate to high yields. The presented rearrangement reaction, in which the presumed N-acylated intermediate reacts intramolecularly via nucleophilic aromatic substitution, results in a formal two-carbon insertion.