MHT CET202613 April 2026Morning ShiftChemistryAminesActual
Which of the following reagents is used to convert -CN group to - CH ₂ NH ₂ group?
Options
- ACrO ₃
- BNa + C ₂ H ₅ OH
- CH ₃ PO ₄
- DAl ₂ O ₃
Correct answer
B. Na + C ₂ H ₅ OH
Step-by-step solution
The conversion of a cyano group ( -CN ) to a primary amine group ( -CH₂NH₂ ) is a reduction reaction. Sodium and ethanol ( Na + C₂H₅OH ) act as a reducing agent, providing nascent hydrogen which reduces the nitrile to a primary amine. This reaction is known as the Mendius reduction. R-CN + 4[H] Na + C₂H₅OH R-CH₂NH₂ The other reagents are not reducing agents for this conversion: CrO₃ is an oxidizing agent, while H₃PO₄ and Al₂O₃ are typically used for dehydration. Answer: Na + C ₂ H ₅ OH