In the first step of the
reaction mechanism the precursor molecule 2-nitrobenzaldehyde
4 is protonated, often by
sulfuric acid, to intermediate
5, followed by an
electrophilic attack to
benzene (other arenes can be used as well). The resulting
benzhydrol 6 cyclisizes to
7 and finally to compound
8. Treatment of this intermediate with
nitrous acid (
sodium nitrite en sulfuric acid) leads to the N-
nitroso acridone
11 via intermediates
9 en
10. The N-nitroso group is removed by an
acid in the final step. The procedure is an example of a
one-pot synthesis. ==References==