Oxidation And Reduction Reactions

Step 1: Identifying the reaction type.
In this reaction, phosphorous acid ( ) is used as a reducing agent. The nitro group ( ) is typically reduced to an amine group ( ) under certain conditions, but in the presence of phosphorous acid, it gets reduced to a hydroxyl group ( ) instead.
Step 2: Reaction Mechanism.
The nitro group ( ) in the aromatic ring is reduced by phosphorous acid. The phosphorous acid acts as a reducing agent and reduces the nitro group to a hydroxyl group ( ) rather than reducing it to an amine ( ) or other products. The product formed is .
Step 3: Conclusion.
Therefore, the final product of the reaction is the methylated phenol (i.e., ).