# Reduction of nitrobenzene with LiAlH4 and NaBH4

After searching a lot on the internet I've found that nitrobenzene is reduced by LiAlH4 to the following compound whose naming I couldn't do.

I couldn't find the mechanism for this reaction anywhere. Can someone tell what is the mechanism for it?

## 1 Answer

The structure you provided is known as azobenzene . It is a parent compound in a well-known family of aromatic azo compounds. The compounds usually are not very thermally stable, but often have intense color and are used as light duty dies (or as pH or other indicators) Aliphatic azo compounds are not stable at all and very prone to fragmentation with formation of molecular nitrogen and free radicals and some of them are used exactly for that.

I couldn't find the mechanism for this reaction anywhere

The reduction of the nitro-group might procede through attack of hydride onto the nitrogen atom or electron transfer onto the group with subsequent reaction of the anion with proton (the exact mechanism depends on conditions and reagents). It can produce a wide amount of monomeric products, in particular: nitrosocompounds, hydroxilamines and amines. It is known, that amines can react with nitrosocompounds forming the $\ce{N=N}$ bond. It looks like the first step in the reaction is a nucleoplilic attack of the amine nitrogen onto nitroso nitrogene with subsequent elimination of water.

• +1 for providing reference to the mechanism. I saw the mechanism at many places but was not able to find a satisfying reference. You have one. – Weijun Zhou Jan 10 '18 at 12:03