NEETChemistryAmines
Given the following reaction sequence: Chloroethane Reagent A X Reagent B Propan-1-amine Identify the correct set of reagents A and B.
Options
- AA = alc. KCN , B = Na(Hg) / C ₂ H ₅ OH
- BA = AgCN , B = LiAlH ₄
- CA = alc. KCN , B = Sn + HCl
- DA = alc. KCN , B = Br ₂/ aq. NaOH
Correct answer
A. A = alc. KCN , B = Na(Hg) / C ₂ H ₅ OH
Step-by-step solution
The conversion of chloroethane (2 carbon atoms) to propan-1-amine (3 carbon atoms) involves an ascent of the amine series, which requires the addition of one carbon atom. Treatment of chloroethane with alcoholic KCN (Reagent A) results in nucleophilic substitution to form propanenitrile ( CH ₃ CH ₂ CN ) as the major product (Intermediate X). CH ₃ CH ₂ Cl + KCN (alc.) CH ₃ CH ₂ CN + KCl The reduction of propanenitrile to propan-1-amine requires a strong reducing agent such as LiAlH ₄ , H ₂/ Ni , or Na(Hg) / C ₂ H ₅