N-Methyl-N-pyridylnitramines form corresponding methylamino-nitropyrid
ines in 74-90 % yield when heated (120-130 degrees C) in chlorobenzene
without an acidic catalyst. N-(P-Pyridyl) nitramine behaves analogous
ly while remaining primary pyridylnitramines rather decompose than rea
rrange. The rearrangement can he carried out in the anisole or m-xylen
e solutions without cross-nitration, hence migration of the nitro grou
p must have an intramolecular character. Some analogies in the thermal
and acid-catalyzed rearrangements have been observed. Various ortho/p
ara ratios can be explained assuming different mechanisms of hydrogen
transfer in the intermediary sigma-complexes.