Reduction of Nitro Groups to Nitroso Groups
Reduction of Nitro Groups to Nitroso Groups: Mechanism
The first step consists of protonating the nitro group followed by reduction to a derivative with three-valent nitrogen.
Protonation and loss of water yield the nitroso compound.
Normally, the nitroso compound is further reduced rapidly and cannot be isolated during the reduction in acidic solution.
On the other hand, reduction of aromatic nitro compounds in alkaline solution give rise to competing reactions which significantly slow down further reduction . Under these conditions the nitroso compounds can be isolated .