Question
Which of the following reagents is used to convert -CN group to - CH _2 NH _2 group?
MHT CET
Chemistry
Amines
2026
MHT CET 2026 (13 April Shift 1)
MHT CET Chemistry Question (2026) — Solution
Options
- A. CrO _3
- B. Na + C _2 H _5 OH
- C. H _3 PO _4
- D. Al _2 O _3
Answer
B. Na + C _2 H _5 OH
Step-by-step solution
The conversion of a cyano group (-CN) to a primary amine group (-CH_2NH_2) is a reduction reaction. Sodium and ethanol (Na + C_2H_5OH) 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 + C_2H_5OH R-CH_2NH_2 The other reagents are not reducing agents for this conversion: CrO_3 is an oxidizing agent, while H_3PO_4 and Al_2O_3 are typically used for dehydration. Answer: Na + C _2 H _5 OH
Related: Chemistry — Amines · All PYQ Banks