Jm. Bakke et J. Riha, Nitration of pyridine compounds. The reaction of N-nitro-1,4-dihydro-4-pyridinesulfonic acid, ACT CHEM SC, 53(5), 1999, pp. 356-359
The reactions of N-nitropyridinium nitrate (1) and 2,6-dideuterio-N-nitropy
ridium nitrate (2.6-d(2)-1) with SO(2)xH(2)O-HSO3- have been studied. The r
esults are consistent with a reaction scheme in which the formed N-nitro-1,
.4-dihydro-4-pyridinesulfonic acid (2) did not react directly to give 3-nit
ropyridine but existed in equilibrium with 1 and 2,6-d(2)-1 from which N-ni
tro-1,2-dihydro-2-pyridinesulfonic acid (3) was formed. From 3, 3-nitropyri
dine was formed by a [1,5] sigmatropic shift of the nitro group.