Polycyclic N-hetero compounds. XXII Reaction of pyridine N-oxides and Pyrazine di-N-oxides with formamide

Reactions of pyridine N-oxides, pyrazine di-N-oxides, and their benzologues with formamide are described. Carbamoylation mainly occurred at aromatic ring with loss of the N-oxide oxygen atom, however, 2,4,6-trimethylpyridine 1-oxide gave 2- and 4-pyrimidinyl derivatives.