 
       
      
    How is benzonitrile converted into benzaldehyde?
 
                
                  To convert benzonitrile (C6H5–CN) into benzaldehyde (C6H5–CHO), the reduction method used is Stephen's reduction.
The reagent used in the Stephen reduction is- Stannous chloride (SnCl2), Hydrochloric acid (HCl), followed by hydrolysis (with water). $$
C_{6}H_{5}–CN \text {(Benzonitrile)} → C_{6}H_{5}–CH=NH·HCl \text {(Imine Salt)} →C_{6}H_{5}–CHO (Benzaldehyde)
$$
 
                