Stephen aldehyde synthesis

Stephen aldehyde synthesis, a named reaction in chemistry, invented by Henry Stephen (OBE/MBE). This reaction involves the preparation of aldehydes (R-CHO) from nitriles (R-CN) using Tin(II) chloride (SnCl2), hydrochloric acid (HCl)  and quenching the resulting iminium salt ([R-CH=NH2]+Cl-) with water (H2O).

Overall, the reaction scheme is as follows: