An alkyl cyanide froms an amide when it is treated with

Explanation

When an alkyl cyanide (R-CN) is treated with hydrogen peroxide (H₂O₂) in the presence of a base like sodium hydroxide (NaOH), it undergoes partial hydrolysis to form an amide (R-CONH₂). This reaction is known as the Kumaraswamy Reaction or Partial Hydrolysis of Cyanides.

Reaction Mechanism

Step 1: Hydroxylation of Cyanide Group

The cyanide group (-CN) reacts with hydrogen peroxide and hydroxide ions from NaOH, resulting in the formation of an imidic acid intermediate (R-C(=NH)(OH)).

Step 2: Tautomerization

The imidic acid tautomerizes to form the stable amide group (R-CONH₂).

Balanced Chemical Equation

R-CN + H₂O₂ + NaOH → R-CONH₂ + H₂O

Key Points

• Role of H₂O₂: Acts as an oxidizing agent, facilitating the hydroxylation of the cyanide group.
• Role of NaOH: Provides the necessary basic medium for the reaction to proceed efficiently.

Why Other Options Are Incorrect

• H₂O + HCl: In acidic conditions, alkyl cyanides undergo complete hydrolysis to form a carboxylic acid (R-COOH) instead of an amide.
• NaOH + H₂O: In basic conditions without H₂O₂, cyanides are hydrolyzed completely to carboxylates (R-COO^-).
• H₂SO₄ + H₂O: Sulfuric acid promotes complete hydrolysis to carboxylic acids, similar to HCl.

Final Answer

The reaction of an alkyl cyanide with H₂O₂ + NaOH results in the formation of an amide through partial hydrolysis. This method is efficient for controlled synthesis of amides without complete hydrolysis to carboxylic acids.