Hoffman Reaction: Conversion of Amides to Amines

The correct answer is option 'C', Hoffman reaction. The Hoffman reaction is a chemical reaction that can convert amides into amines. This reaction involves the conversion of an amide functional group (-CONH2) to an amine functional group (-NH2). The reaction is named after the German chemist August Wilhelm von Hofmann, who first discovered this reaction in the mid-19th century.

The Hoffman reaction proceeds through a process known as Hofmann degradation. This reaction is typically carried out by treating the amide with a strong base, such as sodium or potassium hydroxide (NaOH or KOH), in the presence of an oxidizing agent, such as bromine (Br2) or chlorine (Cl2). The reaction can be summarized as follows:

RCONH2 + NaOH + Br2 → RNH2 + Na2CO3 + 2HBr

Where R represents an organic group.

The mechanism of the Hoffman reaction involves several steps:

1. Formation of the isocyanate intermediate: The strong base (NaOH or KOH) deprotonates the amide, forming an alkoxide ion. The alkoxide ion then reacts with the oxidizing agent (Br2 or Cl2) to form an isocyanate intermediate.

2. Rearrangement of the isocyanate: The isocyanate intermediate undergoes a rearrangement, resulting in the formation of an isocyanate ion. This rearrangement step is often referred to as the Hofmann rearrangement.

3. Hydrolysis of the isocyanate: The isocyanate ion is then hydrolyzed by water (H2O) to form an amine and a carbamate salt.

4. Formation of the amine: Finally, the carbamate salt is treated with acid to release the amine.

The Hoffman reaction is an important synthetic tool in organic chemistry, as it provides a straightforward method for converting amides to amines. Amines are versatile functional groups that can be found in many biologically active compounds and pharmaceuticals. Therefore, the conversion of amides to amines is of great significance in drug discovery and development.

In summary, the Hoffman reaction is a chemical reaction that can convert amides to amines. It involves the treatment of the amide with a strong base and an oxidizing agent, leading to the formation of an amine. This reaction is widely used in organic synthesis and has practical applications in the pharmaceutical industry.