Question

Which of the following reactions is appropriate for converting acetamide to methanamine ?

• A. Hoffmann hypobromamide reaction
• B. Stephen's reaction
• C. Gabriel phthalimide synthesis
• D. Carbylamine reaction

Answer 1

The Correct Option is A

To determine which reaction is appropriate for converting acetamide to methanamine, let's analyze the reactions given in the options.

1. Hoffmann hypobromamide reaction: This is a well-known reaction to convert amides to amines with one fewer carbon atom. This mechanism involves the reaction of an amide with bromine and an alkali, usually in the presence of a strong base like NaOH. The reaction pathway leads to the removal of one carbon atom as carbon dioxide, ultimately converting acetamide (CH₃CONH₂) to methanamine (CH₃NH₂):
   \text{RCONH}_2 + Br_2 + 4NaOH \rightarrow RNH_2 + Na_2CO_3 + 2NaBr + 2H_2O
2. Stephen's reaction: This reaction involves the reduction of nitriles to aldehydes using stannous chloride and hydrochloric acid in the presence of ether. It is not suitable for converting acetamide to methanamine since it deals with a different functional group conversion.
3. Gabriel phthalimide synthesis: This method is used to synthesize primary amines from alkyl halides using phthalimide. It is not applicable to converting acetamide to methanamine, as it does not involve amides as starting materials.
4. Carbylamine reaction: This reaction is used to synthesize isocyanides (carbylamines) from primary amines, chloroform, and an alkali. It is irrelevant for converting amides to amines and, thus, not suitable for this transformation.

In conclusion, the Hoffmann hypobromamide reaction is the correct choice for converting acetamide to methanamine. Other options either involve different reactant classes or serve entirely different synthetic purposes.