Laboratory Methods of Organic Chemistry - Sciencemadness Dot Org

336 NAPHTHAZAKIN
namely, by reductive-oxidative fusion with fuming sulphuric acid and
sulphur (S2O3) in the presence of boric acid (R. Bohn, R. E. Schmidt).
The production of naphthazarin from 1 : 5- or 1 : 8-dinitronaphthalene
under similar conditions constitutes a more readily intelligible prototype
of this complicated reaction.
It consists essentially in a rearrangement to the quinoneoxime, which
is then hydrolysed and partially reduced.
0 NOH
NOHO