Question

Write Stephen reaction for the preparation of aldehyde.

Answer 1

Nitriles are reduced to imine hydrochloride by stannous chloride in the presence of hydrochloric acid which on acid hydrolysis gives corresponding aldehydes. This reaction is called Stephen reaction.

\[\ce{\underset{(Nitrile)}{R - C ≡ N}+ 2[H] ->[SnCl2,HCl] \underset{(lmmine hydrochloride)}{R - C ≡ N·HCl} ->[H+][H3O+] \underset{(Aldehyde)}{R - CHO} + NH4Cl}\]