This question involves identifying the correct functional group transformation from a carboxylic acid derivative to an amine. The scheme shows a reaction where a compound with a specific functional group X is converted to an amine (Ph-CH₂-CH₂-NH₂) using reagent Y.

The starting compound is Ph-CH₂-COOH (phenylacetic acid). To form an amine, we need to convert the carboxylic acid group into an amine group. This is typically achieved through the Hofmann bromamide degradation reaction.

Step 1: Formation of Amide
First, the carboxylic acid (Ph-CH₂-COOH) is converted to an amide. The amide functional group is CONH₂. So, X should be CONH₂.

Step 2: Hofmann Degradation
The amide (Ph-CH₂-CONH₂) undergoes Hofmann degradation with Br₂ and NaOH to form an amine with one less carbon atom. The reaction is:

This gives the desired product: phenylethylamine (Ph-CH₂-CH₂-NH₂). Note that the carbon chain length reduces by one.

Why other options are incorrect:

• X = CN: Reduction with H₂/Ni would give Ph-CH₂-CH₂-NH₂, but it requires an extra step to convert COOH to CN, and it is not direct.
• X = CONH₂, Y = H₂/Ni: Reduction of amide gives amine, but it would yield Ph-CH₂-CH₂-NH₂ without loss of carbon, which is not the case here.
• X = COOCH₃: Reduction with H₂/Ni would give alcohol, not amine.

Final Answer: X = CONH₂, Y = Br₂ / NaOH

Related Topics

Hofmann Bromamide Degradation: This reaction converts a primary amide to a primary amine with one less carbon atom using bromine and sodium hydroxide. It involves the formation of an isocyanate intermediate.

Conversion of Carboxylic Acids to Amines: Carboxylic acids can be converted to amines via the amide intermediate. The Hofmann degradation is specific for primary amides to yield primary amines.

Formulae

General reaction for Hofmann degradation: