Answer to Question #169558 in Organic Chemistry for khushi

Question

Explain the reduction of nitrobenzene using different reagents.

Answer 1

The reduction of nitrobenzene in an acidic medium can be described by the equations:

Ph-NO2-->Ph-N=O-->Ph-NH-OH-->Ph-NH2

The reduction of nitrobenzene in an alkaline medium can be described by the equations:

Ph-NO2-->Ph-N=O-->Ph-NH-OH, where Ph-N=O can react with Ph-NH-OH with formation Ph-N=NO-Ph (compound with carges: N+ and O-), then it forms Ph-N=N-Ph, later it can be reductied into Ph-NH-NH-Ph. A strongly alkaline environment leads to the formation of by-products, recovery should be carried out carefully, for example, with NaHS: 4Ph-NO2+6NaHS+H2O=4 Ph-NH2+3Na2S2O3